Contents...In the preparation of organometallic compounds of pEatinum metals removal of solvents may...

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PLATINUM METALS REVIEW

A quarterly survey of research on the platinum metals and of developments in their applications in industry

V O L . 1 8 O C T O B E R 1 9 7 4

Contents

Coordination Compounds of the Platinum Group Metals

Ruthenium as a Binder for Cemented Carbides

The Behaviour of Platinum Catalysts for Ammonia Oxidation

Macroscopic Aggregation in Palladium Blacks

The Fabrication of Iridium Crucibles

The Izvestiya of the Platinum Institute

Modern History of Temperature Measurement

Abstracts

New Patents

Index to Volume 18

N O . 4

Communications should be addressed to The Editor, Platinum Metals Review

Johnson Matthey & Co Limited, Hatton Garden, London ECl P 1 A E

Platinum Metals Rev., 1974, 18, (4),

Coordination Compounds of the Platinum Group Metals A REVIEW OF THEIR PREPARATIVE METHODS AND APPLICATIONS

By M. J . Cleare Research Laboratories, Johnson Matthey & Co Limited

Strictly speaking, most compounds of the platinum group metals can be classified as coordination compounds. For our purposes they will be divided into three main groups :

(n) The common commercially available starting materials such as oxides and chlorides. Organometallic complexes - which usually contain at least one metal- carbon bond, are soluble in organic solvents and are generally hydrophobic in nature. (This includes phosphine complexes.) Purely inorganic complexes-which are usually soluble in aqueous systems and are generally hydrophilic in nature.

The compounds in group (a) account for the greatest proportion of the production of platinum group metal chemicals. However, the other coordination complexes in groups (b) and (c ) are starting to find increasing applications in various fields. This article discusses the methods of manufacture and uses of these compounds. Those in group (c) can often be produced relatively easily by modification and scale-up of laboratory preparations but group (b ) contains many compounds which involve new technology if multiple small batches are to be avoided. Volatile and odorous solvents, inert atmospheres and high pressure syntheses are sometimes involved.

Homogeneous Catalysis Over the last decade interest and expansion

in the field of homogeneous catalysis have

been phenomenal. Many of the systems employed have involved noble metal coordination compounds, particularly those with dS electronic configurations that tend to perform oxidative addition reactions. A majority of these complexes fall into group (b) and require relatively sophisticated preparative and recovery techniques. Hydrogenation and hydroformylation reactions have attracted most attention but oxidation, olefin isomerisation and hydrosilation have also been investigated.

Effective catalysts for hydrogenation of olefins and acetylenes include the ds complexes [Rh(H)CO(PPh,),], [RhCI(PPh,),],

[Ir(CO)Cl(PPh,),] with trans-[Pt(H)Cl (PEtJ2] and [PtCl(SnCl,)(PEt,),] somewhat less potent. Also, Ru(I1) and Os(I1) d6 species such as [RuC12(PPh,),] and [Os(H)Cl (CO)(PPh,),] have been extensively studied (I) .

The complex [RhCl(PPh,),] (often known as Wilkinson's catalyst) is probably the most important hydrogenation compound. It has been shown to hydrogenate successfully -C=C- bonds in a wide variety of substrates (e.g. olefins, cyclic monoenes and dienes, terpenes , and exocyclic methylene groups) with the great advantage that under mild conditions it does not reduce other functional groups (I) (e.g. keto, hydroxy, cyano, nitro, chloro, azo, ether, ester, carboxylic acid). A cyclic mechanism has been proposed and this is probably typical (2). (See opposite, where S =solvent.)

[Rh(CO)W'PhJJ, [Ir(H)CO(PPh,)J, and

Platinum Metals Rev., 1974, 18, (4), 122-129 122

I n the preparation of organometallic compounds of the pEatinum metals the removal of solvents may be achieved rapidly by rotary evaporation. Here dimethyl formamide is being removed from a rhodium carbonyl complex

RhC1(PPh,)zolefm cis-RhH2C1(PPh,),S

/ I-/ RhC1(PPh3)& + paraffin

These phosphine compounds can be prepared by reduction of the halide starting materials from group (a). The reaction can often be achieved in one step, particularly where the reducing agent can also act as a carbonyl donor. For example, the action of formic acid or formaldehyde on rhodium trichloride gives a pale yellow solution containing [Rh(CO),Cl,]- which yields [Rh(CO) Cl(PPh,),] on the addition of triphenylphosphine (2, 3). In the preparation of


[RhCl(PPh,),] from rhodium trichloride, reduction occurs with triphenylphosphine and ethanol (2).

Similarly, [Os(H)Cl(CO)(PPh,),] can be prepared directly from (NH,),[OsCI,] and triphenylphosphine in 2-(P-methoxyethoxy)- ethanol with the hydride and carbonyl ligands arising from decomposition of the solvent. However, the rate of heating is critical if a high yield and good quality product are to be obtained. The above preparations are generally carried out in a single vessel and are relatively easy to scale up.

In general, heterogeneous techniques are well established for hydrogenations and widespread industrial usage of coordination compounds is unlikely. However, the specific case of asymmetric hydrogenation is more promising (4). In this case a complex con-

123

taining asymmetric phosphine ligands cataly- However, the preparation of these asym- ses a hydrogenation reaction to give an excess metric complexes is a complicated procedure of a particular optical isomer. The chirality involving several steps. For example, o-ani- of the phosphine ligand can be centred either sylmethylcyclohexylphosphine requires six on the phosphorus atom or on a hydrocarbon stages (4) : side chain. A pertinent example is found in the pharmaceutical industry in the manufacture of a amino acid derivatives of both the natural (L) and \

CH3X

heat P(OCHS)L -~

'\ unnatural (D) series. S0Cl2'

o - A n i s y l m e t h y l - ,-

cyc lohexy 1 phos phine (-)-'-u 0 (A) (5): when com- + IISlC1, I

I I stei eospecific

OCH3 in the form [RhA, ' QCH, reduchon 1 L nicntlml P-CH~ (A) plexed with rhodium

" CH3 (diene)]BF,, (diene= 7 TH3 resolution step I ( >) -;;-O-menthsl r,~-hexadiene), can (, 1-i-b --=--

catalyse the hydrogenation of a-acyl- tWO o ~ ~ l c a l 0 &M@r 0 i - 1

aminoacrylic acids to give L o r D amino ((R) and (S) forms)

R, cow \ / 25°C

COOT1 Rhodium complexes are beginning to I replace the traditional cobalt carbonyls R, CH,- C -1I \ / 4

H2, isopropanol

p r e s s u r e s H NHCOK, sub-atmospheric NHCOR, in hydroformylation (0x0) reactions :

acids with optical yields of 80 to 90 per cent, as shown here. The (4 )-phosphine gives the L acid and the (-)- phosphine yields an excess of the unnatural D series. Effectively one is resolving a few kilograms of catalyst to save resolving thousands of kilograms of product.

Freeze drying is used to remove water from heat-sensitive compounds. This technique is being employed here to d T three platinum group metal compounds simubaneously

Platinum Metals Rev., 1974, 18, (4), 124

two odical isomers MFBr

CO,H 2 RCH==CH2-+ R.CH,.CH,.CHO

The major advantages of the rhodium system are the higher straight chain: branched chain ratio of the product and the use of a much lower reaction pressure which still gives an activity that may be orders of magnitude higher than for the cobalt catalyst (I). The active species is generally considered to be [Rh(H)CO(PPh,),] (6). These reactions are generally performed in the presence of excess triphenylphosphine and, consequently, many %(I) complexes that are soluble in the reaction system are active catalysts since they are converted to the above species in the presence of H, and CO. Suitable compounds include [Rh(H)CO

acac] (acac =acetylacetonate anion). The preparative intermediate for these

species is a solution containing [Rh(CO),Cl,]- (which yields the important starting material [Rh(CO),Cl] on evaporation to dryness), which can be produced

(PPh&I, [Rh(CO)C1(PPhJJ and [R-WCO),

_.I

NaBH, + PPh, trichloride by the action of L s PPh, 1 from hydrated rhodium 'Rh(Co)z

several reducing carbonyla-

The large excess of triphenylphosphine is thought to suppress dissociation but it gives rise to much more complex rhodium recovery procedures.

Other potential homogeneous catalytic applications include olefin isomerisation, which usually occurs to some extent during hydrogenation, but this has found little industrial application compared to the heterogeneous type. The dioxygen complex [Pt(PPh,),O,] is very reactive and can catalyse the oxidation of triphenylphosphine to its oxide ( IO), isocyanides to isocyanates ( IO), hydrocarbons to hydrocarbon hydro- peroxides (II), and cyclohexene to cyclohex- 3-one and cyclohexene oxide (12). This complex may find industrial application and it is fairly readily prepared from K,[PtCl,] by reaction with excess triphenylphosphine in ethanol. The initial product is [Pt(PPh,),], which is converted to the catalyst by the passage of oxygen. Hydrosilation of olefins

IRhCOCI(PPh,) .,I

ting agents such as formic acid or carbon monoxide (3). The relevant reactions are indicated here (7, 8).

.1 [ Rh(H)CO(PPh3)3] (absence of an infra-red band at 1960 cm-1 indicates that the reaction is complete)

A possible mechanism has been suggested by Wilkinson et al. and this corresponds closely with that proposed for the cobalt system (6, 9). Starting with [Rh(H)CO(PPh,),] we have :

[Rh(H)CO(PPh,),] -= [Rh(H)CO(PPh,),] + PPh3

CO addition li dissociation

olefin [Rh(H)(CO),(PPh,),(R.CH = CHZ)] 7- [Rh(H)(C0)2(PPh,),I tl f a s t

[Rh(H) CO(PPh,),] + - - - [Rh(H)z(CO)(PPh,)z(R.CH2.CH2.Co)] -t

R . C H ~ . C H ~ . C H O


iourifv bv vacuum sublimation at 80°C

hydride transfer

carbonyl transfer

dihydride formation

excess PPhl

acac/Na,CO,

has been achieved using &(I) and, particularly, Pt(I1) complexes. One such patented process uses considerable quantities of trum-[Pt(Et,S),Cl,] (13). This is prepared by the action of the ligand on K,[PtCl,] but the crude product needs careful recrystallisation and characterisation (infrared spectrum and melting point) to separate and identify the isomers.

Plating Electrolytes Most platinum metal plating solutions are

based on specific coordination complexes which fall into group (c). Indeed, some of the most successful baths have been discovered via the routine screening of ionic complexes. The preparative methods are generally quite simple and the compounds are produced on a relatively large scale. Ammine and nitro ligands figure prominently. A successful platinum bath is based on the acid form of [Pt(NO,),SOJ--, which is prepared from [Pt(NO,),IZ- by the action of sulphuric acid. Semi-bright palladium baths are based on [Pd(NH,),](NO,),, which is prepared by dissolving palladium in dilute nitric acid, followed by warming with excess ammonia. Thin bright palladium deposits are produced from trans-[Pd(NH,), (NO2),], which is made up to pH 8-9 with ammonia before use and thus must exist in solution largely as [Pd(NH,),](NO,),. The mechanism by which ionic (particularly anionic) complexes electroplate is not well understood and does not appear to have been studied extensively. Small changes in the complex structure can cause large differences in plating ability and quality. A particularly interesting example is the successful ruthenium plating salt Ks[Ru,NCls(HzO)z], which contains a bridging nitrido ligand and was prepared during investigations into nitrosyl complexes (14). Without routine screening it would have been difficult to predict that this very stable complex would be the best ruthenium plating salt yet discovered. I t performs best with the addition of ammonium formate-a mild reducing agent. It is pre-

pared by the action of SnC1, on K,[Ru(NO) Cl,], followed by careful recrystallisation to remove any traces of impurities containing coordinated (SnC1,)-.

Special additives to electroplating baths are usually required to give brighter and less stressed deposits, and these can be as important as the complex itself to the final result. Chelating agents such as EDTA or EDTA complexes often perform this function.

The other class of coordination complexes -referred to as group (b) earlier in this article-has found limited application in the area of vapour deposition techniques. Some organometallics, particularly acetyl- acetonates and other p-diketone complexes, have sufficiently low decomposition temperatures to enable plating to be done on plastics, rubber and even paper (IS, 16).

Biological Applications It has been demonstrated recently that

certain Pt(I1) amine complexes have potent anti-tumour activity against a wide range of transplantable animal tumours. These studies have been covered previously in this journal (17). A number of compounds are at present undergoing extensive animal trials, while cis-[Pt(NH,) ,Cl,] is entering the second stage of human clinical trial. Although it has some toxicity problems, this compound has shown genuine activity against human neoplasms, particularly those arising in the testicles or ovaries. Active complexes (against transplantable animal turnours) have been of the general type cis-[PtA,X,] and are all neutral with cis leaving (reactive) groups X of intermediate lability, e.g. C1-, Br-. However, some dicarboxylate groups, which are relatively non-labile in vitro, e.g. oxalate and malonate, can give rise to active compounds. The amine ligands A also play an important role and should be relatively inert and neutral. They have a pronounced effect on the activity, and this has not yet been related to any physical parameter, such as kinetic or solubility effects.


A smaI1 scale autoclam jitted with a glandless rotary agitator used in the preparation qf platinum group metal cnr- bortyls

These anti-tumour amine complexes, cis-[PtA,X,] and [Pt(A)X,], may be prepared by several routes (18). The most generally applicable method involves the initial precipitation of the corresponding iodo complex by the reactionofthe amineand K,[PtI*I.

K,[PtIJ -]-2A+ cis-[PtA,I,] 4 f 2 K I

The iodide can be converted to complexes containing other anionic ligands via the aquo species produced using silver nitrate.

cis-[PtAJ,] 1. 2AgN0, + 2H,O+ C~~-[P~A,(H,O),](NOJ, + 2AgI

The discovery of anti-tumour activity was preceded by the finding that certain platinum complexes were strong bacteriocides and at certain concentrations below a lethal dose could cause filamentous growth in Escherichia coli (19). This property of affecting cell division but not growth led to the anti- cancer investigations. As yet all complexes which show anti-tumour activity also cause


some filamentous growth but the reverse is not true. Anti-bacterial applications are obviously limited, not only due to the wide spectrum of relatively non-toxic (to humans) antibiotics but also because silver, with its powerful “oligodynamic” effect at 0.5 p.p.m. or less, is already in considerable use and has fewer toxic effects,

Certain complexes of ruthenium and rhodium have also shown the ability to cause filamentous growth in bacteria. Again this is mainly limited to chloro and chloroamine species. Truns-[Rh(py),Cl,]Cl and [ R u ( N H ~ ) ~ Cl,] are particularly potent in this respect but neither has shown any appreciable anti- tumour activity (20). However, mer- [Rh(NH,),CI,] and some of its derivatives have shown activity against the ADJ/PCBA

A wide range (4000 to 200 cm-') infra-red spectrophotometer used to charaeterise platinum group metal coordination complexes. The low frequency region (600 to 2 0 0 ~ m - ~ ) is particularly useful for this type of compound

and Walker carcinosarcoma tumours (21).

These amine and ammine complexes are usually prepared by direct reaction with the corresponding chloro species, although controlled ammination agents, such as ammonium acetate or carbonate or a buffered system, are often preferred.

Other Applications An interesting new application for @-diketo-

natobis(carbony1)-rhodium complexes is in gas chromatography columns for the separation of olefins (22). The 3-trifluoroacetyl- camphorate is particularly good and is marketed for this purpose. The complexes are prepared by the action of the corresponding p-diketone on [Rh(CO),CI] 2. The columns contain approximately 0.02 per cent of the rhodium complex and the separation is due to the different degrees of interaction of the olefins with the square planar Rh(1) system.

Other uses for compounds in group (b) include additives for industrial purposes

(solubility in heavy organic solvents is a necessary requirement) and both groups (b) and (c) are occasionally involved as starting materials for the preparation of certain heterogeneous catalysts.

Characterisat ion The characterisation of industrially pro-

duced coordination compounds is generally achieved by elemental analysis and comparison of spectral data with that available in the literature. In this respect infrared spectroscopy is the major technique and a wide range instrument is essential in order to study the interesting metal-ligand modes below 650 cm-I. These often allow isomeric variations (both structural and linkage) to be detected. The degree of characterisation depends on the eventual use. For example, the anti-tumour complex cis-[Pt(NH,),Cl,] is subjected to a variety of techniques, including ultra-violet/visible spectroscopy and paper chromatography, while criteria for plating salts are not usually as severe. The


presence of cis-[Pt(Et,S),Cl,] in the trans isomer causes a lowering in melting point, making this a sensitive criterion in this case, more so than the far infra-red spectrum. In catalysis applications chloride is often un- desirable and strict limits are placed on its presence.

References I B. R. James, “Homogeneous Hydrogenation”,

Wiley-Interscience, 1973 2 J. A. Osborn, F. H. Jardine, J. F. Young

and G. Wilkinson, J. Chem. SOC., A, Inorg. Phys. Theor., 1964, 1711

3 M. J. Cleare and W. P. Griffith, J . Chem. SOC., A, Inorg. Phys. Theor., 1969, 372

4 W. S. Knowles, M. J. Sabacky and B. D. Vineyard, Chem. Technol., 1972, (Oct.), 590

5 W. S. Knowles, M. J. Sabacky and B. D. Vineyard, Chem. Commun., 1972, 10

6 D. Evans, J. A. Osborn and G. Wilkinson, J. Chem. SOC., A, Inorg. Phys. Theor., 1968, 3133

7 F. Bonati and G. Wilkinson, J. Chem. SOC., 1964,3156

8 D. Evans, G. Yagupsky and G. Wilkinson, J. Chem. SOC., A , Inorg. Phys. Theor., 1968, 2660

9 C. K. Brown and G. Wilkinson, J . Chem. SOC., A, Inorg. Phys. Theor., 1970, 2753

10 S. Takahashi, K. Sonagashira and N. Hagihara, J . Chem. SOC. Japan, 1966, 87, 610

11 E. W. Stern, Chem. Commun., 1970, 736 12 A. Fusi, R. Ugo, F. Fox, A. Pasini and S.

Cenini, J . Organomet. Chem., 1971, 26, 417 13 Imperial Chemical Industries Ltd., British

Patent 1,023,797; French Patent 1,437,798 14 C. W. Bradford, M. J. Cleare and H

Middleton, Platinum Metals Rev., 1969, 13,

15 E. C. Marboe, U.S. Patent 2,430,520 16 “Vapour Deposition”, ed. C. F. Powell,

J. H. Oxley and J. M. Bloeher, Wiley, New York, 1966

17 B. Rosenberg, Platinum Metals Rev., 1971, 15, (z), 42; M. J. Cleare and J. D. Hoeschele, Platznum Metals Rev., 1973, 17, (I), 2

18 M. J. Cleare and J. D. Hoeschele, Bioinorg. Chem., 1973, 2, 187

19 B. Rosenberg, T. Krigas and L. Van Camp, Nature, 1965,205,698

20 M. J. Cleare, Coord. Chem. Rev., 1974, 12,

21 M. J. Cleare, T. A. Connors, J. D. Hoeschele, B. Rosenberg and L. Van Camp, presented at 2nd Internat. Conf. on Platinum Com- plexes in Cancer Chemotherapy, Oxford, 1973, to be published

22 E. Gil-Av and V. Schurig, Anal. Chem.,

(3x90

(4), 349

1971, 43, (141, 2030

Ruthenium as a Binder for Cemented Carbides A potential means of improving the per-

formance of cemented carbides is to raise the melting point of the binder constituent, thereby increasing the hardness and reducing the amount of wear at the high temperatures involved in machining operations. Whereas conventional binder phases are based on nickel, cobalt or iron, which form eutectics with the carbides at melting points between 1300 and 14oo3C, suitable binders for higher melting points must be chosen from refractory transition or platinum metals. Most platinum metals, however, decompose transition metal carbides but ruthenium has been shown to form an eutectic with titanium carbide at 1840°C.

Two papers giving a deeper insight into the Tic-Ru system were presented recently at the 8th International Plansee Seminar on “Refractory and Wear Resistant Materials”. J. S. Jackson of Production Tool Alloys Ltd., Sharpenhoe, Bedford and R. Warren and Professor M. B. Waldron of the University of Surrey studied the sintering behaviour,

microstructure, hardness, and resistance to cracking over the whole Tic-Ru composition range. They found that titanium carbide did not decompose to form graphite during sintering and that after sufficient milling alloys of almost full density were produced below the 1840°C eutectic temperature. Good sinterability is partly the effect of good ad- hesion between the carbide and ruthenium. These alloys are harder than cemented carbides incorporating a nickel binder but ruthenium is less effective than either cobalt or nickel in preventing cracking of T i c .

The studies also showed that Tic-Ru is particularly promising as a potential cutting tool material. Small amounts of nickel, cobalt or iron picked up during milling assist full densification of Tic-Ru at I~oo‘C, which is a convenient sintering temperature. Nickel, for example, does not seriously affect the properties of Tic-Ru and the melting point of a binder phase containing both ruthenium and nickel remains higher than that of conventional cemented carbides.


The Behaviour of Platinum Catalysts for Ammonia Oxidation STUDIES BY CONTROLLED ATMOSPHERE MICROSCOPY

By R. T. K. Baker and R. B. Thomas Atomic Energy Research Establishment, Harwell

and J. H. F. Notton Research Laboratories, Johnson Matthey & Co Limited

Continuous observations by controlled atmosphere microscopy of the efects of heating platinum and rhodium-platinum alby wires in ammonia- air mixtures indicated that attack on the wire surfaces predominates at the grain boundaries. The alloy wires, including used commercial catalyst gauzes, exhibited the formation of mobile promontories preceding the formation of angular crystalline platelets, whereas pure platinum wires did not show so much promontory growth, even at higher temperatures.

The first stage in the production of nitric acid is the catalytic oxidation of ammonia with air to give nitric oxide. This process is usually carried out over a multi-layered stack of rhodium-platinum alloy gauzes at operating temperatures of 800 to goo"C. Owing to increased demand for nitric acid, relatively high operating pressures (-8 atm) are now being used. Of major concern in this process is the anomalous loss of platinum from the catalyst gauzes. This is a function of such variables as local temperature, oxygen concentration and linear gas velocity, and, consequently, is most pronounced at high pressures. I t is thought that adsorption of reactants on the catalyst surface results in a weakening of the Pt-Pt bonds, and at 900°C platinum is lost as platinum oxide, PtO,

In the present investigation we have used controlled atmosphere microscopy techniques in an attempt to observe and understand the initial stages in the behaviour of the catalyst when heated in a 10 per cent ammonia-air mixture. In these experiments we have

(1,2).

compared the behaviour of pure platinum, 10 per cent rhodium-platinum and specimens of used commercial catalyst gauzes.

Controlled Atmosphere Electron and Optical Microscopy

Transitory features of systems undergoing change often remain unobserved during conventional post-reaction examination. At Harwell we have overcome this restriction with the use of controlled atmosphere electron microscopy (3). The equipment consists of a JEM 7A electron microscope fitted with a gas reaction cell, enabling the specimen to be observed continuously by electron transmission while exposed to gas atmospheres with pressures of up to 230 torr and temperatures of up to IZOO'C.

Figure I is a schematic representation of the JEOL AGI gas reaction cell (B) and stage (A). Gas passes through a channel in the cell to a region between two 70 pm diameter apertures (C), one in the body of the cell and the other mounted in the top cap. The specimen lies on its heater between these


Fig. 1 Diagram of the JEOL AGI gas reaction cell ( B ) and stage (A) used at Harwell for controlled atmosphere electron microscopy of platinum and rhodium-platinum specimens

apertures. Gas exits into the specimen chamber through the apertures and is all pumped away via an auxiliary vacuum line, thus preventing gas leakage into the main microscope column.

To take full advantage of the microscope (Fig. 2), sophisticated continuous recording facilities are incorporated. Part of the electron beam falls upon a transmission phosphor screen and this image is focused on to a high sensitivity “Plumbicon” television camera outside the vacuum chamber. The output from the camera is fed to a monitor and is recorded simultaneously on video-tape.

The specimen is mounted over a 300 pm diameter hole in a platinum heater ribbon supported on a mica ring. A platinum: 13 per cent rhodium-platinum thermocouple is spot welded to a point close to the hole. A direct current passed through the heater ribbon heats the specimen.

Controlled atmosphere optical microscopy studies were carried out with a Leitz 1750

heating stage fitted to a Vickers M4a Photo- plan microscope (4). This technique enabled the reaction between the ammonia-air mixture and platinum to be examined at higher pressures (2 atm) and over longer periods than was convenient in the electron microscope gas cell.

The platinum catalyst wires used in this work were supplied by Johnson Matthey & CO Limited. The optical studies were carried out with specimens containing a platinum: 10 per cent rhodium-platinum junction. Specimens were connected directly to the electrical leads of the cell and were positioned so that the junction could be observed. The temperature at this point was measured with an optical pyrometer. The 10 per cent ammonia-air mixture was maintained at a pressure of t atm and a flow rate oft llmin. Contamination of the quartz viewing window of the cell by water vapour prevented continuous observation of the reaction by closed circuit television but the window could be


cleared for long enough periods to take photographs at hourly intervals and record the temperature.

Specimens and Studies Specimens for electron microscopy in-

vestigations were prepared by threading platinum wires, 10 per cent rhodium-platinum wires and sections of used gauze through holes in the heater ribbon on either side of the 300 pm diameter viewing hole so that the wire stretched across the central region. In all cases experiments were carried out with specimens in the “as received” condition and also with similar specimens that had received a rigorous cleaning treatment.

The gases used in this work-ammonia and air-were obtained from Air Products Limited


Fig. 2 The apparatus used .for controlled atmosphere electron microscopy includes the microscope itselJ together with equipment to display and record images of the specimens wnder test

and were both of 99.5 per cent purity. They were used without further purification.

Two series of studies were carried out. In the first, experiments were conducted in the optical gas cell on platinum: 10 per cent rhodium-platinum thermocouples and, in the second, experiments were carried out in the electron microscope gas cell with fine wires. All these experiments were conducted in 10 per cent ammonia-air mixtures up to temperatures of at least 900°C.

Optical Microscopy Studies Figures 3a and 3b show the effect of heating

the specimen platinum : 10 per cent rhodium- platinum thermocouple in 10 per cent ammonia-air at z atm to 950°C. Before the reaction the surface of the specimen was

132

Fig. 3a

Fig. 3b Fig. 3 Controlled atmosphere optical microscopy qj' 10 per cent rhodium-platinum thermocouple w i r e in 10 pc'r cent ammonia-air at 2 atm to 95OOC: ( a ) before reaction, (0) after 12 hours exposure with sonic indictit ion o j the~formation of pits or knolls

Fig. 4 Controlled atmosphere electron microscopy showed that the 10 per cent rhodium-platinum wire is generally quite smooth before reaction i n 10 per rent ammonia-air

quite smooth but after one hour's reaction it was observed to have roughened considerably. Examination after a two-hour period showed that attack had occurred predominantly in the region of grain boundaries. There are indications from the micrograph in Fig. gb, taken after 12 hours exposure, of either pits or knoll formation. These two features could not be distinguished by reflectance microscopy


Electron Microscopy Studies The results reported in this section are in

each case taken from five reproducible experiments, and in the cases of platinum and 10 per cent rhodium-platinum wires the behaviour was found to be unaffected by the cleaning treatment.

When a piece of platinum wire was heated in 10 torr of 10 per cent ammonia-air in the gas cell of the electron microscope, the original smooth surface of the specimen did not change until 970°C. At this temperature knolls, some of which appeared to be triangular in shape, were formed on the surface. The size of these growths was observed to increase in width from 50 to 125 nm over a period of 26 min at 970°C. On raising the temperature to IIOO'C secondary growths in the form of needles and platelets appeared on the knolls, giving rise to a more ragged appearance of the original growths.

Similar experiments were conducted with 10 per cent rhodium-platinum wire specimens. The appearance of the wire before reaction was generally quite smooth, as seen in Fig. 4, but on heating to 700°C in 10 torr of 10 per cent ammonia-air the surface took on a rippled form. When the temperature was raised to 8 ~ 5 ° C ~ isolated knolls were observed to form. These moved quite freely along the surface, as shown in Figs. 5a and 5b and sometimes collided to form larger growths. The knolls ranged in width from IOO to 200 nm and were too dense for penetration by the electron beam. Figures 6a to 6d form a sequence taken from the T V display showing the effect of heating the specimen from 890 to 925°C. As the temperature was increased

Fig. 5 Knolls formed on the surface of 10 per cent rhodium-platinum wire above 800°C moved quite freely along the wire surface. The interval between f r a m e ( a ) (lef) and f rame (b) (right) was 1 s

Fig. 6 Promontory formation on 10 rhodium-platinum wire heated in 10 % ammonia-air at 10 torr. Secondary platelet and needle growth took place on the sides of the promontories, e.g. A and R. ( a ) (upper Zeft) 890"C, 0 m i n ; ( b ) (upper right) 890"C, 2.3 rnin; (c ) (lower left) 890"C, 6.1 min; ( d ) (Zower rzght) 925"C, 8.0 min


from 855 to 890°C the knolls increased in size to produce eventually large promontories, and secondary platelet and needle growth took place on the sides of the promontories, e.g. A and B, shown in Figs. 6a and 6b, respectively. The platelets were much thinner than the parent growths and the appearancc of ex- tinction contours across their surfaces indicated their crystalline nature. Several features of the reaction are clear from Fig. 6, not least being the dramatic change in morphology of the surface on increasing the temperature from zs to 890°C. The growth of the promontory with platelet A at its tip can be seen and, moreover, this facet retains the shape of its leading edge, indicating that growth is occurring by transport of material from the bulk rather than by gas phase deposition. There are also indications that material might also be lost at this stage, e.g. platelet B appears to increase in size and then disappears. In one sequence a needle was observed to grow and eventually break off' at its base. I t was also evident that many of the platelets were quite flexible at 924°C and were getting progressively thinner; the density was decreasing towards the edges, suggesting that material was being lost preferentially from these areas.

Finally, specimens of used commercial catalyst gauze were examined by this technique to discover whether further reaction with 10 torr of 10 per cent ammonia-air took place. An initial survey of the specimen showed that there were a number of promontories on the roughened surface, some of which had platelets associated with them. As the temperature was raised to 700°C, slight changes in the profile of the promontories were noted and these became appreciable at 890°C. The length of promontories increased at the expense of a decrease in width. Platelet growth occurred at the edges of the promontories. High magnification examination of the platelets showed that they were crystalline and had well defined angular shapes, as shown in Fig. 7 , and in some cases there was denser material within them. As the reaction

Fig. 7 Crystalline platelets formed on the sides of promontories on a commercial catalyst gauze when heated in 10 % ammonia-air at 10 torr to 980°C

progressed some platelets continued to grow whereas others decreased in size. The sequence shown in Fig. 8 gives an indication of the extent of the reaction. I t can be seen that there is a dramatic change in the outline of the tip of the promontory and, although this growth appears to increase in length, this is accompanied by a general decrease in its width. All these observations indicate that there could be appreciable restructuring and transport of material within the bulk.

Behaviour of the Wires The behaviour of the platinum gauze

catalyst and of the 10 per cent rhodium- platinum wire appeared to be identical in many respects, whereas platinum wire was significantly less reactive under the same conditions. This difference could be due to a variation in the actual surface temperatures of specimens during reaction, associated with the exothermicity of ammonia oxidation. 10 per cent rhodium-platinum alloy, being the more active catalyst, might be expected to be at the higher temperature and hence exhibit the more active behaviour. Garton and Turkevich (5) have demonstrated that structural changes in platinum occur only in the presence of both ammonia and air, no such changes being observed in either the individual reactants or any of the products.


Fig. 8 Increase i n length and decrease in width of the tip of a promontory formed on the surface of a used commercial catalyst gauze specimen heated to 890°C in 10 per cent ammonia-air at 10 torr. (a ) before reaction, room temperature; ( b ) 890°C- 2 min; ( c ) 890"C, 4.5 min; (d) 890"C, 20.0 min

The present experiments clearly indicate that platelets are produced on the edges of the wires by a consecutive process, their growth being preceded by the agglomeration of mobile surface knolls to form promontories, and it was these features which gave rise to platelet formation. Continuous observation of platelet growth suggests that the latter stage involves platinum transport from the bulk rather than vapour transport of volatile platinum oxides.

It is tempting to speculate that attack on the catalyst surface occurs preferentially at grain

boundaries with the eventual formation of promontories and the platelet material, and that ultimately platinum is lost from the platelets as volatile compounds.

References I R. W. Bartlett, J. Electrochem. Sac., 1967, 114,

z E. J. Nowak, Chem. Engng. Sci., 1966, 21, 19;

3 R. T. K. Baker and P. S . Harris, J. Phys. E,

4 R. T. K. Baker and R. B. Thomas, J . Crystal

5 G. Garton and J. Turkevich, J. Chem. Phys.,

547

1969,24,42I

Sci. Imtrum., 1972,5, (8), 793

Growth, I972,1z, 185

19543 51, 516


Macroscopic Aggregation in Palladium Blacks OPTIMISATION OF CATALYTIC AND SORPTIVE PROPERTIES

By P. A. Sermon Department of Industrial Chemistry, Brunel University, Uxbridge, England

The basic particles of palladium blacks have been observed to cluster into macroscopic aggregates. Hydrogen treatment increases remarkably both the extent and degree of ordering of these aggregates. This may result in a substantial percentage of their surface areas being unavailable for adsorption. A theoretical model is proposed to account for the effects of this phenomenon in these and other unsupported and supported catalysts. Its predictions can be used to optimise their surface area and activity.

Microscopic aggregation or sintering involves the clustering of atoms. It is well known that this increases the size of the basic particles and thus the physical properties (I), the sorptive properties (2) and the catalytic properties (3) of materials. Macroscopic aggregates are the result of the clustering of these basic particles and their effects upon the activity of a catalyst have not been considered previously.

Macroscopic aggregation has been studied in five palladium black samples denoted A, B, C, D, and E. These samples, which were prepared by Johnson Matthey & Co. Limited, contained widely differing average particle sizes (A: 141 nm; B: 69 nm; C: 16 nm; D: 14 nm; E: 7 nm) (4, 5) . Figure I shows a macroscopic aggregate in palladium black A, which is typical of those found in all untreated palladium blacks. It is readily seen that macroscopic aggregates are relatively large open-structured ensembles of basic particles. These aggregates can be defined in terms of the average coordination number, N, for each particle, the average size, 2R, of each particle (R equals the radius of a basic particle which is spherical), and the number, n, of constituent particles,

The simplest macroscopic aggregate, involving two basic particles in contact at point X, is illustrated in Fig. 2. It is clear that molecules of thickness d normal to the surface of the particles cannot adsorb in the area bounded by B, B’, C and C’. This surface area of each particle that is unavailable for adsorption, SNON, is given by 2xR2>: [d/(R+d)] (5) . It can readily be shown (5)

Fig. 1 A scanning electron micrograph of the untreated palladium black sample A (R= 70.5 rim) X 7600


that in general the percentage surf- -ce area unavailable for adsorption by these molecules is given by 5oN/(K+1), where K is the ratio R/d. This percentage increases as N increases, R decreases or d increases. Despite this and an abundance of other theoretical predictions (6) of the effects of macroscopic aggregation upon the surface area available for adsorption, little evidence exists (7) for such effects. This is presumably due to the low values of N normally found in aggregates (7) and other random packed beds (8), or to high ratios R/d that are unfavourable for detection.

Palladium Aggregates after Hydrogen Treatment

Hydrogen pretreatment of the palladium blacks at temperatures between ambient and 60°C caused each of the samples to form a single macroscopic aggregate. Figure 3 shows

Fig. 3 A single macroscopic aggregate (0.6 c m ~ 0.6 cmXI.0 cm) formed on treating palladium black sample C ( R - 8 nm) with hydrogen at 50°C for two hours

such an aggregate (0.6 cm x0.6 cm X 1.0 cm) formed by palladium black C, containing basic particles 8 nm in radius. I t is clear that this mild hydrogen treatment caused a remarkable increase in the extent of macroscopic aggregation. However, very little agitation (mechanical or ultrasonic) of an aggregate resulted (4) in its disintegration and thus the bonding between basic particles in the aggregates was not strong. It may be that these inter- particular chemical bonds or menisci (4, 9) are formed at the local temperatures produced on the surface of the particles during the hydrogen treatment of these blacks which possessed oxidised surfaces.

Sorptive and Catalytic Effects of Aggregation

Hydrogen chemisorption at ambient temperature has shown (4) that no sintering occurs in the samples during hydrogen treatment at temperatures up to 60°C. Now nitrogen


adsorption (4) at - 196°C and alkene titration (10) at 50°C have been used to estimate the surface areas available for adsorption of nitrogen and pent-I-ene in a series of palladium blacks which had been subjected to this mild hydrogen pretreatment and which had formed single macroscopic aggregates. Their estimates of the total surface area are compared with the true surface areas of the samples in Fig. 4. From this it is seen that the total surface areas estimated for black D (by alkene titration) is only 35 per cent of its true surface area and that the surface area for black E is only 37 per cent (by nitrogen adsorption) or 70 per cent (by alkene titration) of its true surface area. Since it is known that under the conditions used no sintering occurred, these differences in surface area must be the result of macroscopic aggregation.

Assuming that the thicknesses, d, normal to the surface of nitrogen at -196°C and of pent-I-ene at 50°C are 0.35 (11) and 0.81 nm (5) respectively, and knowing that these two palladium samples have average particle

radii, R, of 7 nm (black D) and 3.5 nm (black E) (4), the value of R/d or K can be determined for each adsorbate/adsorbent system. Experimental values of the percentage surface area which is unavailable for adsorption equal 5oN/(K + I) and sub- stituting in the corresponding estimates of K we find that within experimental error N has the values of 12 (data for black D estimated by alkene titration and data for black E estimated by nitrogen adsorption) and 3 (data for black E estimated by alkene titration).

Twelve is the maximum value of the average coordination number N and corresponds to close-packing of basic particles within the macroscopic aggregates. This is the first time that such high coordination numbers have been found in unsupported adsorbents or catalysts. The value of N in untreated samples is known ( 5 ) to be low and therefore it follows that the mild hydrogen pretreatment induces a high degree of ordering in the macroscopic aggregates in addition to increasing the extent of the phenomenon.

Despite the effects of macroscopic aggregation upon the surface area available for adsorption, no effect upon the ability of these blacks to catalyse the hydrogenation/isomerisation of pent-I-ene has been detected (5).

Optimisation of Specific Surface Area and Activity

Macroscopic aggregation after hydrogen pretreatment has been shown to cause a significant diminution of the specific surface area which is available for adsorption in a series of palladium blacks. It follows that it also reduces their activity per unit weight. The effects of the phenomenon increase as N increases, R decreases or d increases.

Although the phenomenon has been observed for a series of palladium blacks, it undoubtedly occurs in other unsupported catalysts and even in supported catalysts (12). Let us consider if it is possible to maximise the surface area, and hence activity, of a catalyst using the model of macroscopic aggregation postulated here.


As an example, in Fig. 5 the surface areas per gram of palladium (47-cR2-N.SNON).n, where n is the number of constituent particles n=3/(4pnR3) (5) and p is the particle density, are plotted as a function of R for various values of d, assuming N is twelve. I t is normally assumed that, in the absence of special adsorption sites at certain values of R(2), decreasing the value of R always increases the specific surface area available for adsorption and thus the activity of the catalyst. However, it can be seen in Fig. 5 that the available surface area goes through a maximum at RSnsv determined by the size of the adsorbate molecule. It is only if R is greater than RsmaxJ that the specific surface area does indeed increase with decreasing R, but below Rsmm decreasing R has the opposite effect. Therefore, the maximum available surface area and thus maximum

activity for a catalyst is given for any adsorbate at Rsmax.

If we calculate ( 5 ) approximate values of d for pent-I-ene, stilbene, ethylene and methanol to be 0.81, 0.57, 0.50 (13) and 0.07 nm, then for palladium samples exhibiting maximum macroscopic aggregation (N = IZ), RSmav has the values 7, 4.5, 3.5 and less than I nm respectively. Thus for a palladium black required for the hydrogenation of pent-I-ene, the hydrogenation of stilbene in the liquid- phase (14)~ the hydrogenation of ethylene or as the electro-catalyst for the reforming of methanol in a fuel cell (IS), it would be disadvantageous to decrease the average particle size of the catalyst below 14, 9, 7 and about I nm respectively. Clearly, whether macroscopic aggregation must be considered an important factor when designing a catalyst of optimum surface area and activity depends

Platinum Metals Rev., 1974, 18, (4), 1 40

upon the size of the adsorbate molecules. I n the case of methanol reforming the phenomenon will not be an important consideration, unlike the position for the hydrogenation of the unsaturated hydrocarbons, where RSmiLx is greater than the smallest palladium crystallite radii which can be prepared in the unsupported state.

Catalyst Design The wide variation in the value of N found

in the palladium blacks after hydrogen pretreatment and the uncertainty in the value of d makes precise estimates of KSmax for other catalysts difficult. Nevertheless, it would not be unprofitable when designing a catalyst (particularly an unsupported one, but also a supported one), to use an average value of N (i.e. N =6) and approximate estimates of d, to predict the optimum particle size which will give the maximum specific surface area available for adsorption (2RS,J and thus maximum activity. There is no justification for decreasing ad infinitum the crystallite size of unsupported catalyst particles (16) in macroscopic aggregates without regard to this perhaps eventually having a detrimental effect upon the activity per unit weight of the catalyst.

References I H. Kubicka, J . Catalysis, 1966, 5, (I), 39 2 R. van Hardeveld and A. van Montfoort,

Surface Sci., 1966~4,396 3 J. W. E. Coenen, R. Z. C. van Meerten and

H. T. Rijnten, Proc. 5th Internat. Cong. Catalysis, 1973, I, 671; J. R. Anderson and Y. Shimoyama, Ibid., 695

4 P. A. Sermon, J. Catalysis, 1972,24,460,471 5 P. A. Sermon, 3. Catalysis, in press 6 B. G. Aristov, A. P. Karnaukhov and A. V.

Kiselev, Russ.J. Pkys. Chem., 1962, 36, 1159; S. J. Gregg and K. S. W. Sing, “Adsorption, Surface Area and Porositv”. Academic Press.

7 8

9

I0

I1

I2

13

I4

I5

16

1967, p. 178; W. H. Wid;, J . Pkys. Chem.; 1964,68, 1029; D. Dollimore and G. R. Heal, J. Colloid Interface Sci., 1973, 42, 233; A. P. Karnaukhov and A. V. Kiselev, Russ. J . Phys. Chem., 1960, 34, 1019 W. H. Wade, J . Phys. Ckem., 1965, 69, 322 W. 0. Smith, P. D. Foote and P. F. Busang, Phys. Rev., 1929, 34, 1271 T. Baird, Z. Pahl and S . J. Thompson, J. Chem. Soc., Faraday Trans. I , 1973, 69, 5 0 G. C. Bond and P. A. Sermon, Reaction Kinet. Catalysis Lett., 1974, I, (I), 3 S. J. Gregg and K. S. W. Sing, “Adsorption, Surface Area and Porosity”, Academic Press, 19679 P. I57 D. Pope, D. S. Walker, L. Whalley and R. L. MOSS, J. Catalysis, 1973, 31, 335 J. H. Cfint,J. Ckem. SOC., Faraday Trans. I, 1973169, 1320 R. L. Augustine, “Catalytic Hydrogenation, Techniques and Applications in Organic Synthesis”, Arnold, London, 1965, p. 59 D. P. Gregory, “Fuel Cells”, Mills & Boon, London 1972 For example, see British Patent 1,322,330

The Fabrication of Iridium Crucibles DEEP DRAWING TECHNIQUES INVESTIGATED

Iridium has the greatest tensile strength of the platinum group metals and its melting point is 2443°C. Consequently, it has not proved to be an easy metal to fabricate in the past but efforts are continuing to improve the methods of working it. This technology has been stimulated by the incrcasing use of iridium in crucibles for growing single crystals from oxide melts (B. Cockayne, Platinum Metals Rev., 1974, 18, (3), 86-91).

A recent report from G. Reinacher of Degussa, Hanau (Metall, 1974, 28, (7), 657-661) now shows that iridium can only be deep drawn satisfactorily to form seamless crucibles if the work on the iridium sheet is carried out above the recrystallisation tem-

perature of the metal at -~ooo”C. Tests included cupping from iridium discs 0.3 mm thick and 55 mm diameter, some being of cast iridium sheet and others of sintered iridium with and without ruthenium additions. The former for shaping the iridium was first heated to 62oOC and later to 750°C. Variations in technique also included trials at pressures between 200 and 1000 kp, various widths of drawing gap, and intermediate annealing after the first 5.5-8 mm cupping. However, none of these techniques eliminated the formation of creases and the conclusion that working above -IOOO”C is necessary was therefore reached.

F. J. S.


The Izuestiya c of the Platinum Institute THE WORLD’S FIRST PLATINUM METALS JOURNAL

By Professor George B. Kauffman California State University, Fresno, California, U.S.A.

The thirty-two volumes of the Izvestiya Sektora Platiny i Drugikh Blagorodnykh Metallov (Annals of the Sector for Platinum and Other Noble Metals, hereafter called Izvestiya for the sake of simplicity) bear more than a passing resemblance to the thirty-two piano sonatas of Ludwig van Beethoven. Beethoven’s sonatas span a period of 27 years (1796 to 1823), through which can be traced the composer’s increasing mastery of form and the development of his unique genius. Similarly, the volumes of Izvestiya span a not too different period of 35 years (1920 to 1955) and reflect the development of Soviet research on the platinum metals from its humble beginnings during the chaotic Civil War to its full maturity during the post-World War I1 era.

Like the Beethoven sonatas, too, the Izvestiya is unique. It was the first, and, for more than three decades of its existence, the only journal devoted exclusively to the platinum metals. Two years after its demise, its unique position was assumed by Platinum Metals Review, the first issue of which appeared in January 1957.

The Platinum Institute The founding of the Izvestiya is intimately

connected with the world-famed Platinum Institute of the USSR (I) and with its founder and first director, Lev Aleksandrovich Chugaev (1873-1922) (2-5). During World War I, in response to increased demands for platinum catalyst needed for the contact process for manufacturing sulphuric acid, Chugaev, together with Vitalii Grigor’evich

Khlopin (1890-1950), and Vyacheslav Vasil’evich Lebedinskii (1888-1956) (6) de- vised industrial methods for refining platinum and its congeners. In 1915 Nikolai Semenovich Kurnakov (1860-1941) (7, S), another pioneer in the systematic exploitation of Russian mineral resources (including platinum) and discoverer of “Kurnakov’s reaction” for differentiating cis from trans isomers of divalent platinum and palladium, together with Vladimir Ivanovich Vernadskii (1863-1943) and Aleksandr Evgen’evich Fersman (1883-1945) organised as part of the Rossiiskaya Akademiya Nauk (Russian Academy of Sciences) a commission known as the Kommissiya PO Izucheniyu Estestvenykh Proizvoditel’nykh Sil Rossii (Commission for the Study of Russian Natural Productive Sources), abbreviated KEPS. In response to this commission’s appeal, Chugaev drafted a report arguing that platinum, one of Russia’s most valuable natural resources, should not be exported in raw form but that a state monopoly should be created for locating, producing and processing this important metal. He proposed the formation of an institute to be devoted to the systematic study of all aspects of research and development on the metals of the platinum group.

After the Bolshevik Revolution of October 1917, Chugaev’s dream became a reality. In 1918 he was appointed director of the newly created Institut PO Izucheniyu Platiny i Drugikh Blagorodnykh Metallov (Institute for the Study of Platinum and Other Noble Metals) of the USSR Academy of Sciences at Petrograd. On Chugaev’s death in 1922,


The front cover of the$rst issue ofthe Izvestiya ofthel’latinum Institute, published at Petro- grad (Leningrad) in 1920 under the editorship of i t s founder, Z,. A. Chugaev, and his assistants N. K . Pshenitsyn and I . I. Chernyaev

Kurnakov succeeded him as director of the Institute. In 1934 the Institut Fiziko- Khimicheskogo Analiza (Institute of Physico- chemical Analysis, founded in 1918 by Kurnakov as part of KEPS), the Platinum Institute, and the General Chemistry Labora- tory of the Academy of Sciences merged to form the Institut Obshchei i Neorganicheskoi Khimii, IONKh (Institute of General and Inorganic Chemistry) with headquarters in Moscow and with Kurnakov as director. Following Kurnakov’s death in 1941, it was renamed the N. S. Kurnakov Institute of General and Inorganic Chemistry. Academician Il’ya Il’ich Chernyaev (1893-1966) (9), d‘ iscoverer of the trans effect so important in the synthetic chemistry of the platinum metals, was director of the Institute until his death in 1966.

The Imestiyya In accordance with the Soviet policy of

encouraging a Russian chemical literature, Chugaev founded a special journal, the Izvestiya Instituta pa Izuchmiyu Platiny i Drugikh Blagorodnykh Metallov (Annals of the Institute for the Study of Platinum and

Other Noble Metals), to publish the research results of the new institute. Its founding is considered to coincide with the founding of the Institute; from Volume 6 (1928) on, all issues of the journal bear the designation “osnovany L. A. Chugaevym v 1918 g” (founded by L. A. Chugaev in 1918).

The first issue of the new journal, Tom I, Vypusk I (Vol. I, No. I), edited by L. A. Chugaev with the assistance of h’ikolai Konstantinovich Pshenitsyn (1891-1961) and I. I. Chernyaev, however, was not published until 1920 at Petrograd under the auspices of KEPS. A slim volume, 15 cm xzz.5 cm-a size which varied only slightly through the years-it consisted of only 49 pages and two articles, both by Chugaev. The first dealt with the goals and tasks of the Institute (p. I),


The N . S. Kurnakov Institute of GeneraE and Inorganic Chemistry at Moscow from where the Izvestiya was published for many years. The late Academician Ilya Il’ich Chernyaev, who supplied this picture, was an editor of the Izvestiya during its latter years and subsequently became editor of the more general Zhurnal Neorganicheskoi Khimii, which replaced it i n 1956

while the second, “Researches on the Com- plex Compounds of Platinum” (p. 11) was subdivided into two parts--(‘I. On Hydrazine Compounds of Platinum” (co-authored with M. S. Grigor’eva) (p. 14) and “11. On Hy- droxylamine Compounds of Platinum” (co- authored with I. I. Chernyaev) (p. 29). The table of contents was printed in both Russian and French, a convenient practice that continued through Volume 18 (1941), after which the French translation was omitted.

The second issue, Tom I, Vypusk 2 (Vol. I,

No. 2, now considered to be Volume 2,

40 pages), appeared the following year and contained Parts 111-VI of Chugaev’s series “Researches on the Complex Compounds of Platinum”, co-authored with N. K. Pshenitsyn(III), S. S. Kil’tinovich(V), and N. A. Vladimirov(V1). No issue appeared in 1922 or 1923 (or in 1925, 1930, 1934, 1943 to 1946, or 1953). The third issue, Vypusk 3 (No. 3) was published in Leningrad (Petro- grad was renamed after Lenin’s death) in 1924 and “dedicated to the memory of L. A. Chugaev.” For the first time, the name of the journal appears on the title page in French translation, “Annales de l’lmtitut de Platine et des Autres Me‘taux Pre‘cieux,” a practice continued through Volume rg (1941) (at one time Chemical Abstracts used the abbreviation Ann. inst. platine (U.S.S.R.) for the journal). No editor is designated, and the entire volume is devoted to nine articles about Chugaev’s life and work. This volume is designated a joint publication with the

Nauchnoe Khimiko-Technicheskee Iz- datel’stvo N.T.O. (Scientific Chemical-Tech- nical Publishing Firm).

NO volume appeared in 1925, but in 1926 Volume 4, consisting of 519 pages, the longest of all 32 volumes, appeared under the editorship of N. S. Kurnakov and Ernest Khristianovich Fritsman (1879-1942) (10). For the first time the designation SSSR (USSR) appears on the title page in connection with the Academy of Sciences and KEPS. Also for the first time the volume is divided into two sections-( I) Experimental and Theoretical Articles (18 papers) and (2) Reports, Reviews, and Abstracts (Russian translations, complete or abridged, of foreign articles) (IS papers). This two-part format, with the exceptions of Volumes 10

(1932) and 13 (1936), was continued through Volume 16 (I939), and reports of meetings and conferences sometimes appeared in the second part. As is the case with many journals, as the number of original articles increased with time, the abstracts and translations were eventually dropped. Five posthumous articles by Chugaev appeared in Volume 4.

Volume 5, published in 1927 by the Izdatel’stvo Akademii Nauk SSSR (Publish- ing House of the USSR Academy of Sciences) under the editorship of Kurnakov, Fritsman, and 0. E. Zvyagintsev, was dedicated to the centenary of the Russian platinum industry. The zz-paper volume contained not only historical articles on the Russian platinum


In 1936 the title of the Izvestiya was amended to show its connection with the Institute of General and Inorganic Chemistry. It mas then published from Moscow and Leningrad under the editorship of N . S. Kurnukov and 0. E. Zvyagintsev

industry but also reprint- ings of classic 19th century papers by Petr Grigor’evich Sobolevskii (178 1-1841), Kovan’ko the Ist, and Karl Karlovich Klaus (1796-1864) (11). Begin- ning with Volume 8 (193 I), the name of KEPS no longer appears on the title page under Academy of Sciences of the USSR. Beginning with Volume 9 (1932), which is dedicated to the memory of Nikolai Ivanovich Podkopaev (1872-1930), Fritsman’s name no longer appears as editor. Four papers by V. A. Nemilov, Zvyagintsev, Chernyaev, and Aleksandr Abramovich Grinberg (1898-1966) (12) presented for the Platinum Institute at the session of the Academy of Sciences devoted to problems of the Ural-Kusnetsk Region comprise Volume 10, published in the same year.

Beginning with Volume 13 (1936), which contains as a supplement an index to principal works on alloys of precious metals (p. I77), organisational changes are reflected in the change of name of the journal to Izvestiya Sektora Platiny i Drugikh Blagorodnykh Metallov (Annales du Secteur du Platine et des Autres Me‘taux Pre’cieux, Annals of the Sector

for Platinum and Other Noble Metals) and the appearance of “Institut Obshchei i Neorgani- cheskoi Khimii“ (IONKh, Institut de Chimie Gknkrale, Institute of General and Inorganic Chemistry) on the title page, which also now bears the word “MOSCOW” in addition to “Leningrad”. Both places, or no place of publication at all, appear on the title pages until Volume 27 (1952) when the place of publication is given as Moscow only. Al- though Kurnakov died on March 19th, 1941, his name is still listed as editor along with Zvyagintsev’s name on Volumes 18 (1941) and 19 (1942). Strangely enough, his name is bordered in black on Volume IS but not on Volume 19. After a publication gap of five years, Volume 20 (1947)~ edited by I. I.


Chernyaev, 0. E. Zvyagintsev, and A. V. Babaeva, is completely in Russian; no French on the title page or table of contents appears. The words “im. N. S. Kurnakova” following IONKh on the title page reflects the name change of the Institute.

Volume 21 (1948), devoted principally to the Proceedings of the 3rd Conference on the Chemistry of Complex Compounds, held in Moscow on November 13th-17th, 1944, again reflects a change in editorship ; Babaeva’s name is replaced by the name of M. M. Yakshin. Volume 26 (1951) is divided into two sections-the first devoted to experimental results obtained by workers at the Platinum Section of IONKh and the second devoted to the Proceedings of the Fifth All- Union Conference on the Chemistry of Complex Compounds, organised by the Academies of Sciences of the Ukranian SSR and the USSR and held in Kiev on March

Volume 27 (1952), published in Moscow, indicates a change in editorship, the last one for this journal; Yakshin’s name is dropped, and Chemyaev and Zvyagintsev remain as co-editors. Volume 28 (1954) is divided into two sections. The first, consisting of 130 pages, is devoted entirely to the Proceedings of the Conference on the Regularity of the Trans-Effect of I. I. Chernyaev, held in Mos- cow, March 24th to 26th, 1952, with lectures by Chernyaev, Grinberg, Gel’man, Yatsimirskii, and other luminaries of Soviet science. The second section consists of experimental articles.

Volume 30 (1955) contains the Resolution of the Sixth All-Union Conference on the Chemistry of Complex Compounds, held in Moscow, December 1st to 4th, 1953, and, more important for our purposes, an index (actually tables of contents) for Volumes I to 30 (pp. 189-202). This is followed by two detailed indexes for the same volumes-one of authors (pp. 203 to 205) and one of subjects (pp. 206 to 222). Volume 31 (1955) is subtitled “Works on the Chemistry of Complex Compounds” and contains the Resolution of

23rd to 26th, 1950.

the Conference on the Application of Com- plex Compounds in Analytical Chemistry. Volume 32 (1955)~ the last of this important and unique journal, is subtitled “Analysis of Noble Metals (Proceedings of the Third Con- ference on the Analysis of Noble Metals, November 16th to 18th, Ig54)”, and the final article in the entire series (p. 80) reports the resolution adopted at this conference.

Contents of the Izvestiya In his extensive review “The Platinum

Metals,” Raleigh Gilchrist (13) reported that of the roughly eight hundred articles published on this subject from 1915 to 1940, the largest number of papers (circa 28 per cent) were contributed by Russian scientists. A large proportion of these more than two hundred papers appeared in the Izaestiya, which naturally provided the primary publication outlet for Sovict research efforts on the noble metals. All aspects, both theoretical and experimental, were included. Not only were the fields of inorganic, physical, and analytical chemistry included but also an appreciable number of historical or bio- graphical (obituary) articles and lengthy review articles. Among the diverse topics discussed were synthescs of new compounds and improved preparative methods for known compounds, qualitative and quantitative analytical procedures, the Russian platinum industry, extraction and separation methods, refining, metallography, alloys, substitution reactions, stereochemistry and isomerism, nomenclature, and physicochemical studies.

Among the heaviest contributors to the journal were, not unexpectedly, I. I. Chernyaev, 65 contributions; V. V. Lebedinskii, 49; N. K. Pshenitsyn, 42; 0. E. Zvyagintsev, 38; V. A. Nemilov, 37; and A. A. Grinberg, 26. Other leading contributors included A. V. Ablov, A. V. Babaeva, G. B. Bokii, T. A. Vidusova, L. M. Volshtein, A. D. Gel’man, B. G. Karpov, M. A. Klochko, N. S. Kurnakov, M. A. Porai-Koshits, A. M. Rubenshtein, A. A. Rudnitskii, V. G. Tronev, I. A. Fedorov,


E. Kh. Fritsman, and M. M. Yakshin. Although Chugaev died shortly after he founded the journal, he is represented by 19 articles, 12 of which were published posthumously; the last 5 of these were not published until 1929 (Volume 7).

Because of the large number of significant papers included in the Izvestiya, it is difficult to single out the most important ones. A list of the most outstanding articles would certainly include Chernyaev’s 14-paper series (1926 to 1933) on the nitrite complexes of divalent platinum (14), the first paper of which contained the first statement of his famous trans effect (15). This important orientation rule made it possible for the first time to plan systematic routes for carrying out inner-sphere substitution reactions in order to prepare platinum complexes in which all the ligands are different. For example, Chernyaev’s synthesis in 192s of the three possible geometric isomers of the [Pt(NH,) (C,H,N)(NH,OH)(NO,)]+ ion was cited as evidence of a square planar arrangement for platinum(I1) (16). In 1949 Anna Gel’man and co-workers (17) prepared the three isomers of [Pt(NH,)(C,H,N)(Cl)Br]. Chernyaev also utilised the trans effect in synthesising various isomers of platinum(IV), e.g. [Pt(en)(NHJ(Cl)(Br)(NO,)]Cl (IS). Gel’man’s articles with Chernyaev and others on complexes of platinum with unsaturated hydrocarbons such as ethylene (19) can also be cited as important contributions as can Lebedinskii’s series of papers on the complexes of iridium and rhodium (20). Of Grinberg’s numerous papers, his polarisation theory of the trans effect, the earliest explana- tion that still has current application (21), his studies of the acid-base properties of platinum(1V) complexes (22), and his widely used diagnostic method for determining the con- figuration of coordination compounds of platinum(I1) by reaction with oxalic acid (23) deserve special mention.

With the passing years the Izvestiya reflected a broadening in the scope of its subject-matter. Early issues were devoted

exclusively to platinum, and only with Volume 4 (1926) were the other five platinum metals included (osmium, p. 48; iridium, p. 52; palladium, p. 55; rhodium, p. 331; and ruthenium, p. 367). The chemistry of the platinum metals is largely the chemistry of their complexes, so it is not surprising that the journal soon branched out to include coordination compounds of other metals, such as cobalt, gold, silver, chromium, tin, and cadmium. When the Izvestiya ceased publication in 1955, its task was taken over in the following year by the new and broader publication Zhurnal Neorganicheskoi Khimii (Journal of Inorganic Chemistry), with Il’ya Il’ich Chernyaev as editor.

The author wishes to thank the John Simon Guggenheim Memorial Foundation for a Guggenheim Fellowship, the California State University, Fresno for a sabbatical leave, and the California State University, Fresno Research Committee. He also wishes to acknowledge the assistance of Professor Helen Dmitriew, Suzanne M. Cates, and the late Academician Ilya Il’ick Chernyaev.

References I V. V. Lebedinskii, Zzv. Sektora Platiny i

Drug. Blagorodn. Metal., Inst. Obshch. i Neorg.Khim., Akad. Nauk S.S.S.R. (hereafter abbreviated Zzv.), 1924, 3, 81

2 T. M. Lowry,J. Chem. SOC., 1923, 956 3 V. V. Lebedinskii, Zzv., 1948, 21, 18 4 G. B. Kauffman, J. Chem. Educ., 1963, 40,

656; Platinum Metals Rev., 1973, 17, I44 5 0. E. Zvyagintsev, Yu. I. Solov’ev, and I. I.

Starosel’skii, “Lev Aieksandrovich Chugaev” (Izdatel’stvo “Nauka”, 1965)

6 0. E. Zvyagintsev, Zhur. Neorg. Khim., 1957,

7 G. B. Kaufhan and A. Beck,J. Chem. Educ., 1962, 39, 44-49 and references therein

8 Yu. I. Solov’ev and 0. E. Zvyagintsev, “Nikolai Semenovich Kurnakov, zhizn’ i deyatel’nost’ ” (Izdatel’stvo Akademii Nauk SSSR, Moscow, 1960); 0. E. Zvyagintsev, ed., “Nikolai Semenovich Kurnakov v vospominaniyakh sovremennikov i uchenikov” (Izdatel’stvo Akademii Nauk SSSR, Moscow,

9 V. V. Lebedinskii, ‘Il’ya Il’ich Chemyaev” (Izdatel’stvo Akademii Nauk SSSR, Moscow, Leningrad, 1948); V. V. Lebedinskii and A. M. Rubenshtein, Uspekhi Khim., 1953, 23, 241-252;A. V. Babaeva, Zhur. Obshchei Khim., 1953,23,713-717, En. trans. inJ. Gen. Chem. U.S.S.R., 1953, 23, 743-746; N. M. Zhavoronkov, Zhur. Neorg. Khzm., 1967, 12, 291-301, En. trans. in Russ. J. Znmg. Chem.,

2, 1713-1719

1961)

1967,12, 149-156 10 0. E. Zvyagintsev, Zzv., 1948,21, 12-15


11 B. N. Menshutkin, Zzv., 1928, 6, 1-11; J . Chem. Educ., 1934, 11, 226-229; M. E. Weeks, ibid., 1932, 9, 1017-1034; D. McDonald, “A History of Platinum” (Johnson Matthey & Co., London, 1960)~ 175-180; Platinum Metals Rev., 1964, 8, 67-69; G. B. Kauhan, “Dictionary of Scientific Bio- graphy,” ed. C. C. Gillispie (Charles Scribner’s Sons, New York, I97I), Vol. 3,301

12 L. M. Volshtein and G. N. Finashina, “Aleksandr Abramovich Grinberg” (Iz- datel’stvo Akademii Nauk SSSR, Moscow, 1963). This biography contains a bibliography of Grinberg’s publications through 1962.

13 R. Gilchrist, Chem. Rev., 1943, 32, 277-372 14 I. I. Chernyaev, In., 1926, 4, 243; 1927, 5,

15 I. I. Chernyaev, Zzv., 1926,4, 243-275. The definitive statement of the trans effect appeared in Zzv., 1927, 5, 118-156. For a dis- cussion and annotated English translation of the latter paper see Paper 15 of G. B. Kauffman,

102; 1928, 6, 23, 55; 1929, 7, 52, 73, 83, 98; 1931, 8, 37, 5 5 ; 1933, 11, 21, 33, 45, 61

“Classics in Coordination Chemistry, Part 11. Selected Papers (1798-1935)” (Dover Pub- lications, New York, in press).

16 I. I. Chernyaev, Izv., 1928, 6 , 55-97 17 A. D. Gel’man, E. F. Karandashova, and L. N.

Essen, Izv., 1g49,24,60 18 I. I. Chernyaev and 0. N. Adrianova, IN. ,

1949,23, 9; 1955, 31, 34 19 I. I. Chernyaev and A. D. Gel’man, Izv.,

1937, 25, 77; 1938, 1 5 3 5; 19393 16, 21 20 For example, V. V. Lebedinskii, Izv., 1933,

5, 11; 1935, 12, 67; idem and V. S. Volkov, 1935, 12, 79; idem and S. F. Silin, 1937, 14, 33; idem and N. A. Balitskaya, 1938, 15, 13; idem and I. A. Fedorov, 1938, 15, 27; idem and P. V. Simanovskii, 1939, 16, 53

21 A. A. Grinberg, Zzv., 1932, 10,47 22 A. A. Grinberg and G. P. Faerman, Izv., 1931,

8, 115; 1932, 9, 163; idem and B. V. Ptitsyn, 1932, 9J73

23 A. A. Grinberg, Helv. Chim. Acta, 1931, 14, 445; idem and B. V. Ptitsyn, Izv., 1932, 9, 55

Modern History of Temperature Measurement Temperature Measurement at The National Physical Laboratory: Collected Papers 1934-1970 EDITED BY C. R. BARBER, H.M.S.0. London 450 pages A14.60

The accuracy and reliability of the millions of temperature measurements made every day throughout the manufacturing industries of the world depend essentially upon the acceptancy of a recognised practical sale of temperature and on the precise establishment of fixed points such as the freezing points of a number of pure metals. The existence of the International Practical Scale of Temperature, first agreed upon in 1927 and revised in 1948 and again in 1968, is nowadays so much taken for granted that its birth pangs and its evolution tend to be forgotten.

Prior to 1927 the only agreed basis was dependent upon mercury thermometers and the scale was limited to the range oo to 100°C. For some years, beginning in 1911, lengthy discussions took place-interrupted of course by the First World War-between the N.P.L., the Bureau of Standards and the Physikalisch- Technische Reichanstalt, resulting eventually in the first version of our present scale.

A great deal of the credit for the construc- tion of the International Temperature Scale, and particularly for its subsequent revisions, must be given to the workers at the National Physical Laboratory although, of course, the other national standardising laboratories played their part. This collection of papers published by them over a period of thirty-six years gives a survey of their temperature

researches and, although in some respects the book is largely of historical interest, it does in fact make a more useful contribution, in that it brings together papers on particular subjects and also analyses the present state of knowledge in each section, giving a good measure of additional information that was not included in the original papers.

Two major fields of temperature measurement depend, of course, on the peculiar properties of high purity platinum, resistance thermometry and the use of high temperature thermocouples, and each of these techniques is the subject of several of the papers re- printed, many of them contributed by J. A. Hall and C. R. Barber. The earlier contributions of F. H. Schofield and A, Grace which laid the foundations of the now universally employed technique of liquid steel temperature measurement are also included.

Sadly, the editor of this collection of reprints, C. R. Barber, died suddenly in March 1971. He had become recognised as a leading international authority on all aspects of temperature measurement and its associated experimental techniques. His last contribution to this subject makes a most impres- sive record of the successful endeavours of the institution with which he was associated for the whole of his career.

L. B. H.


ABSTRACTS of current literature on the platinum metals and their alloys

PROPERTIES Order-Disorder Transformation in CuPt

DELAVIGNETTE and s. MLINCKX, Phys. Status Solidi A - Appl . Res., 1974, 22, (I), 45-51 The order-disorder transformation in CuPt was studied by means of electrical resistance measurements, transmission electron microscopy and electron diffraction. In heated disordered CuPt, short range order is developing at 20-190’C by the formation of microdomains which grow into long range order domains after further heating.

Ferromagnetic Properties at High Fields and High Pressures of Nickel-Platinum Alloys near the Critical Concentration for Ferromagnetism

E. TORFS, L. STALS, J. VAN LANDUYT, P.

H. L. ALBERTS, J. BEILLE, D. BLOCH and E. P. WOHLFARTH, Phys. Rev. B, 1974, 9, (5), 2233- 2243 Magnetic properties of ferromagnetic Ni-Pt alloys containing 42.9, 45.2, 47.6 and 50.2 at.

Ni were measured at 4-60 K in magnetic fields up to 60 kOe and pressures up to 7 kbar. The effective interaction U was 0.44 eV while the ratio of U to the bare interaction was 0.65.

Non-equilibrium Phases in Al-rich AI-Pt Alloys A. M. TONEJC, A. TONEJC and A. B O N E F A ~ I ~ , J . Muter. Sci., 1974, 9, (4 , 523-526 X-ray diffraction studies of Pt in A1 when the solid solubility of Pt in A1 was extended from o to 2 at. yo by the “two-piston” quenching technique showed an intermediate metastable phase during decomposition, The stability of the AI-Pt solid solution during annealing is also discussed.

Metallurgical Aspects of Binary Alloy Films Grown from the Melt A. OLIVEI, Z. Metallkunde, 1974, 65, (7), 482-488 The properties of solidification structures were studied on 0.1604 Si-Pt and the thermodynamics of the steady state solidification in thin and thick binary films were observed. The problem of microsegregation in cellular and dendritic solidification was also studied.

Diffusion of Hydrogen in 0-Palladium Hydride at High Pressures M. KUBALLA and B. BARANOWSKI, Ber. Bunrenges. PhYS. Chem., 19741 78, (4), 335-338 A relaxation method was applied for the deter-

mination of the intrinsic diffusion coefficient of H, in P-phase Pd hydride up to 23 kbar of equilibrium H2 pressure. The activation energies and frequency factors for diffusion obtained from the temperature dependence of the diffusion coefficients at constant pressure exhibit maximum values of ~ O O - J ~ O O bar, indicating the occurrence of a diffusive motion no longer definable by a single-jump mechanism between adjacent octa- hedral interstitials in the Pd lattice.

Experimental Study of the Critical-point Behaviour of the Hydrogen in Palladium System: I. Lattice Gas Aspects. 11. Specific Heat Y. DE RIBAUPIERRE and F. D. MANCHESTER, J . Phys. C, Solid State Phys., 1974, 7, (12), 2126-

For the H2 in Pd (PdH) system, the critical point was located at Tc=566+1 K, pc=o.29~0.01 atomic HjPd ratio, PC=19.89f0.05 atm (H, pressure surrounding Pd). Critical point ex- ponents 8, y and A were determined for the critical isotherm, the isothermal compressibility of the H, lattice gas and the relaxation time of the elastic after-effect, respectively. Studies of the specific heat of the PdH system through the critical point region using a temperature wave method showed at constant Hz concentration a simple discontinuity at the critical point, corresponding to the critical point exponent, a, equal to zero. Results showed that mean-field theory describes the critical point behaviour of PdH.

Superconductivity in PdH, PdD and PdAgD Systems P. HERTEL, 2. Physik, 1974,268, (z), 111-115 The mechanisms of superconductivity in PdH(D) and PdAgH(D) systems are discussed. The possible participation of the optical phonon modes in the electron-phonon coupling is examined as is their importance for the observed opposite isotope effect in these systems.

2139,2140-2146

High Superconducting Transition Tem- peratures in the Palladium-Noble Metal- Hydrogen System

High superconducting transition temperatures, T,, of 16.6, 15.6 and 13.6 K were observed in Pd-Cu, Pd-Ag and Pd-Au alloys, charged with large amounts of H by means of ion implantation at Tliq,He. A peculiar phase-transition indicates that weak phonon modes might be responsible for

B. STRITZKER, z. Physik, 1974, 268, (Z ) , 261-264


the high T, values. The difference between the maximum T, values may be explained a5 a type of isotope effect Tc xM-?.

Alloys with High Temperature Coefficient of Linear Expansion Mn-Pd Based System M. P. RAMEL' and 0. I. EVDOKIMOVA, Metalloved. Term. Obrab. Metal., 1974, (9, 36-38 Studies of the temperature coefficient of linear expansion in y-phase of Mn-Pd and Mn-Pd-Ni alloys showed that in Mn-Pd alloys the coefficient depended on Pd content. The range of concentration for the stable alloy with high temperature coefficient of linear expansion (36-39.10-'/ "C) was found to be 72-75?:, Mn, 159; I'd and Ni.

The Effect of Palladium on Oxidation Be- haviour of Sintered Tungsten-Chromium- Palladium Alloys T. ITAGAKI and R. YODA, J . Japan Inst. Metals,

The effect of Pd on the sintering and oxidation behaviour of W-Cr alloys was studied and compared with that of Ni which is an effective activator for sintering of W. Both Pd and Ni accelerated the sintering of W-Cr but Pd was more effective.

1974,929 (6L 486-492

On the Constitution of the Palladinm- Germanium Alloys K . KHALAFF and K. SCHUBERT, Z. Metalkunde, 1974,

X-ray, microscopic and thermal studies of the Pd-Ge system showed two previously unknown phases, Pdz,Ge, and Pd,Ge,

X-ray Study of an Amorphous Pd,,Si,, Alloy P. MRAFKO and P. DUHAJ, Phys. Status Solidi A - APPI. Res., r974, 22, (I), 151-155 X-ray diffraction studies of the structure of an amorphous Pd,,Si,, alloy obtained by rapid quenching from the liquid state and an analysis of the radial distribution function showed that the first nearest neighbours were located at 2.83,4.6, 5.5, and 7.7 A. The number of the first nearest neighbours was 11.7.

A Mass Spectrometric Study of the Sublima- tion of Rhodium and the Dissociation Energy of the Molecule Rh,(g) v. PIACENTE, G . BALDUCCI and G. B A R D I , ~ . Less- common Metals, 1974, 37, (I), 123-127 Vapour pressure and derived values of AHo,,,s were measured during sublimation of Rh at 1850-2120 K using the Knudsen effusion-mass spectrometric technique. The resulting average AH02z,as=~33.g~o.4 kcallg-at. At the higher temperatures the molecule Rh,(g) was identified and a value Doo(Rh2)=64.7 kcal/mole for its dissociation energy was determined.

65, (5)1 379-382

The Growth and Characterisation of High- purity Rhodium Single Crystals J. J. RUBIN and D . L. MALM, J . Vacuum sci. Technol., 1974, 11, (I), 389 Studies of magnetic impurity scattering at low temperature were made on high-purity Rh crystals and Rh-Fe alloys grown by electron beam float zoning. Residual gas atmosphere during crystal growth was analysed and the decay of gaseous impurities was observed.

The Activity of Iridium in Iridium-Platinum Alloys by a Transpiration Method E. s. RAMAKRISHNAN and M. s. CHANDRASEKHARAIAH, J . Less-common Metals, 1974, 37, (2), 269-280 I r activity in 3-60 wt.7; Ir-Pt alloys was determined by a transpiration method at 1468-1518 K using 0, at I atm as the reactive carrier gas. The partial pressures of the volatile IrO, in equilibrium with various alloys were determined at each temperature.

CHEMICAL COMPOUNDS The Preparation and Growth of Pure Crystals of K,Pt(CN),Bro,,.3H,0 and

R. B. SAILLANT, R. c. JAKLEVIC and c. D. BEDFORD, Mater. Res. Bull., 1974, 9, (3), 289-294 The preparation of pure single crystals of K,Pt(CN,)Br0.,.3H,O and KzPt(CN),C1,.,.3H,0 were studied. Crystals with reproducible d.c. conductivity and dielectric constants were obtained only when the mixed valence Pt salt contained one halide. The best quality crystals were grown by slow evaporation of solutions which were I M in urea and 0.1 M in the appropriate K halide.

On the &-Effect in Complex Compounds of Divalent Platinum

and v. I. SPITSYN, Izu. Akad. Nauk S.S.S.R., Ser. Khim., 1974, (6) , 1411-1413 Studies of the acidic properties of cis-acidoaquo complexes of Pt(I1) showed that nitro groups intensify the acidity of cis-position H,O molecules compared to that of similar halo complexes. The stability of cis-nitrochloro-, dichloro-, dibromo-, and diiodoethylenediamine complexes of Pt(I1) in aqueous solutions was studied. Hydrolysis of PtEnN0,Cl occurred in fewer stages than hydrolysis of PtEnC1,.

Isomerisation of cis-Dichlorodiammine- platinum(I1) in Aqueous Solution

and V. I. SPITSYN, Izv. Akad. Nauk S.S.S.R., Ser. Khim., 1974, (6), 1239-1242 Studies of ultraviolet spectra of aqueous solutions of cis- and trans-dichlorodiammineplatinum(I1)

K,Pt( CN) $1, ,.3H ,O

N. N. ZHELIGOVSKAYA, S. V. LOGINOV, L. V. POPOV

YU. G. BREUSOVA-BAIDALA, N. N. ZHELIGOVSKAYA

Platinum Metals Rev., 1974, 18, (4), 1 so

showed that UV spectroscopy might be used to identify these isomers. UV and infra-red spectroscopy showed that cis+rans isomerisation occurs spontaneously in aqueous solutions. Study of the Kinetics of Isomerisation of cis-Dichlorodiammine platinum in Aqueous Solution Ibid., i242-i243 The rate of isomerisation of cis-dichlorodiammineplatinum(I1) in aqueous solution is first order. The rate constant is (1.06 & 0.08) x IO-,.

Platinum Bronzes. IV. Preparation, Crystal Chemistry, and Physical Properties

Chem., 1974, 13, (6), 1377-1388 The Na and Cd bronzes Na,Pt,O, and CdxPt30, as well as the bronze-like CaPt,O, were prepared in powder form at I atm and the existence of Pt,O, was also discussed. Syntheses for Cd,Pt,O, and a poorly defined new simple oxide of Pt with stoichiometry Pt,O, are given.

The Preparation and Characterisation of CdIr(OH), and ZnIr(OH), R. F. SARKOZY and B. L. CHAMBERLAND, J. solid State Chem., 1974, 10, (2), 145-150 CdIr(OH), and ZnIr(OH), were isolated in the process of synthesising nevi ternary oxides of the Pt group metals by means of thermal decomposition of hydroxide intermediates. Both compounds crystallise with an ordered Re0,-type structure. CdIr(OH), is tetragonal with a=7.86 A and c=7.g1 a and ZnIr(OH), is cubic with a=7.64 A.

D. CAHEN, J. A. IBERS and J. B. WAGNER, In0i-g.

ELECTROCHEMISTRY Adsorption of Hydrogen by Platinum, Osmium and Their Alloys at Various Temperatures in Hydrochloric Acid Solution I. N. GOLYANITSKAYA, A. A. SUTYAGINA and G. D. VOVCHENKO, Zh. Fiz. Khim., I974,48, (4), 935937 Studies of H, adsorption on Pt, Os, and 24 and 64 wt.?,; 0s-Pt at 10-70°C showed the sizes of the differential isosteric heats of adsorption and of the bonding energy gMe-H to the surface. Electrolyte composition has the most effect on these values for Pt and for Pt-rich 0s-Pt catalysts.

ELECTRODEPOSITION AND SURFACE COATINGS The Role of Accelerators prior to Electroless Plating of ABS Plastic A. RANTELL and A. HOLTZ~MAN, Trans. Inst. Metal.

Studies in the activation of ABS plastic prior to electroless deposition achieved by treatment with mixed SnC1,-PdCI, catalysts showed that the

Finish., 1974, 52, (2), 3r-38

catalytic activity of the ABS surface directly related to the number of catalytic Pd nuclei created. This number depends on the amount of SnCl2-PdC1, catalyst absorbed, the degree of acceleration and the type of accelerator employed.

HETEROGENEOUS CATALYSIS Molecular Oxygen Induced CrystaUite Size Effect in Reduction of Nitric Oxide with Ammonia over Supported Platinum R. J. PASATERI, J. R. KATZER and w. H. MANOGUE, Am. Inst. Chew. Engng. J., 1974, 20, (2), 219-227 The effect of changing Pt crystallite size from 2.7 to 15.5 nm on the specific catalytic activity in NO reduction by NH,, with and without added 0,, was studied over Pt/Al,O, catalysts a t 423-473 K. In the NO-NH, system both specific catalytic activity and selectivity to N z are independent of crystallite size, In the NO-0,-NH, system the specific catalytic activity of the 15.5 nm crystallites is 6 times that of the 2.7 nm crystallites. The NO reduction rate shows dependence on NO to the first power, and on NH, to the power *.

Effect of the Addition of Tungsten Oxide on the Activity and Stability of Platinum/ Alumina Catalysts in the Aromatisation of Hydrocarbons v. N. SELEZNEV, YU. v. FOMICHEV and M. E. LEVINTER, Neftekhimdya, 1974, 14, (2), 210-204 Addition of WO, to Pt/Al,O, catalyst increases its activity. Greatest activity occurs when the W content is 0.2 wt.7;. Effect of the Addition of Tin on the Activity and Stability of Platinum/Alumina Catalysts in the Processes of Aromatisation and Reforming Ibid., 205-208 Sn additions to PtjAl,O, catalyst increase the aromatisation activity, particularly for catalysts with lower Pt contents (0.35 wt.:,). Little coke is formed on Pt/A1,0, with 0.2 wt.% Sn and so the catalyst is more stable during heptane aromatisation and petroleum reforming than unmodified catalyst.

On the Effect of the Chemical Properties of the Surface of Aluminium Oxide on the Hydrogenating Activity of Platinum/ Alumina Catalysts B. B. ZHARKOV, G. N. MASLYANSKII, T. V. ANTIPINA, V. A. RESHETOV, A. Z. RUBINOV and T. M. KLTMENKO, Kinet. Kataliz., i974, 15, (3), 732-737 The surface acidity of A1,0, samples calcined at 300-1 100°C and the hydrogenation activity of Pt catalysts prepared on this support are inversely related. Chemisorption capacity and hydrogenation activity of these catalysts pass through a minimum corresponding to a calcining tempera-


ture of the Al,03 of 500-700°C. This temperature is that of maximum surface acidity of A1,0,.

Effect of the Acidity of y-Al,O, on the Properties of Platinum/Alumina Catalysts in the Aromatisation of Methylcyclohexane and n-Heptane V. G. VLASOV, Neftekhimiya, 1974, 14, (z), 209-214 The specific surface and the dispersion of Pt both increase as the acidity of the A1,0, support is raised. The increased yield of aromatic hydrocarbons from paraffins is due not only to the effect of the acidity on the acceleration of the limiting stage of the aromatisation process but to the higher dispersion of Pt in more acid catalysts.

Catalytic Properties of Platinum on Charcoal Carriers of Different Pore Structure

Chem., 1974,405, (31, 299-306 5'3; Pt/C catalysts were studied to establish the influence of carrier pore structure and Pt dis- persivity on their catalytic properties ; test reactions were the dehydrogenation of cyclohexane, and the dehydrocyclisation of three isometric octanes. A biporous carrier charac- teristic results in optimal activity for cyclohexane dehydrogenation. For octane dehydrocyclisation, pore structure has a strong influence. Micro- porosity strongly reduces the selectivity of the catalyst system.

Investigations on the Synthesis of the Compound PtO,.PCaO and Its Catalytic Properties in the Process of Ammonia Oxidation

Chem. Stosowana, 1974,18, (I), 3-8 PtO,.qCaO is formed by the reaction of CaO with PtO, or, more slowly, by the reaction of CaO with Pt in the presence of 02. Studies of its phases at 293-1473 K enabled them to be identified by X-ray analysis. Oxidation of NH, to NO over PtO,.qCaO indicates that the compound has less catalytic activity than metallic Pt.

B. PARLITZ and K.-H. SCHNABEL, z, Anorg. Allgem.

A. KOLACZKOWSKI, J. KUBICKI and M. SZUSTAKOWSKI,

Chemisorption of Hydrogen on Platinum Black

POLTORAK, Vest. Moskov. Univ., Ser. II, Khim.,

Studies of Hz chemisorption on Pt black over a wide range of temperature and pressure indicated that the technique might be used to determine the degree of Pt dispersion in the catalysts.

Catalytic Oxidation of Hydrogen over Platinum s. J. GENTRY, J. G. FIRTH and A. JONES,J. Chem. SOL., Faraday Trans. I , 1974,70, (3), 600-604 The oxidation of H, on Pt was studied using a

A. 0. TURAKULOVA, V. S. BORONIN and 0. M.

1974, (21, 143-147

microcalorimetric technique. The reaction takes place by two mechanisms, depending whether the surface is in an oxidised or reduced state. On the reduced surface, H, is dissociatively adsorbed and competes with adsorbed O2 for adsorption sites. The reaction rate is higher on the oxidised surface where H, molecules are weakly adsorbed and react with strongly adsorbed 0,.

Platinum Catalysts for Exhaust Emission Control: The Mechanism of Catalyst Poison- ing by Lead and Phosphorus Compounds

MALERBI, Abstr. Papers, 167th Natl. Mtg., Am. Chem. Soc., 1974, (Mar.-Apr.), INDE 90 Studies of the relative toxicity of Pb and P compounds in isolation and in combination are made and the mechanism of Pt catalyst poisoning by Pd and P is compared and contrasted. The relative rates of deactivation by poisoning and other forms of degradation are explored.

The Iduence of the Support and the Method of Reduction on the Amount of the Ionic Form of Platinum in Absorbed Pt Catalysts Z. v. LUK'YANOVA, T. G. MARTYNYUK, v. I.

Zh. FizXhim., 1974,48, (4,928-931 Studies of the Pt(1V) content of Pt catalysts supported on aerosil, SO2, zeolites, Si02-A1,0,, C, WO,, and ZnO, with different amounts of Pt, and with various methods of applying and reducing the Pt showed that no Pt(1V) is contained in samples reduced by NaBH, or in those prepared on zeolites by ion exchange. On storage the Pt(1V) content begins to increase noticeably after three weeks.

G. J. K. ACRES, B. J. COOPER, E. SHUTT and B. W.

SHEKHOBALOVA, T. A. POSPELOVA and N . I . KOBOZEV,

Correlation between the Catalytic Activity and the Surface of Platinum Crystals G. A. SOMORJA1,J. vacuum scz. Technol., 1974, 11, (I), 250 Several catalytic reactions involving hydrocarbons (n-heptane-;. toluene; cyclohexane-2 benzene; benzene-+cyclohexane) were studied on both low and high Miller index Pt surfaces at 10-4 Torr and at zc-450°C using a mass spectro- meter. These reactions did not take place on the (111) crystal face but on several stepped crystal faces. Inspection of the surfaces by LEED indicated the formation of ordered carbonaceous surface structures.

Effect of Chlorine on the Dehydrocyclisation of 2-n-Butylnaphthalene in the Presence of Palladium/Alumina Catalyst

PLATE, Neftekhimiya, 1974, 14, (3), 373-376 Product ratios from C,- and C,-dehydrocyclisation of z-n-butylnaphthalene on Pd/AI,O, and of r-(naphthyl-2)-butene-r on A1,0, are related

L. A. ERIVANSKAYA, G. A. SHEVTSOVA and A. F.


to the C1 content of the catalysts. On those containing 1.4-1.6 wt.", C1 products of C5- dehydrocyclisation predominate.

Dehydrogenation of 2-Alkoxycyclohexanols L. CERVENP, A. MARHOUL and V. Rt??ICKA, Chem.

The catalytic dehydrogenation of 2-alkoxy- cyclolexanols to 2-alkoxyphenols was studied in the gaseous phase, 2-methoxy-, 2-ethoxy, and 2- isopropyloxycylohexanols being used as model compounds. Best results were obtained using a catalyst of 3% Pd/charcoal, modified by 67& K,C03 applied as an aqueous solution to the reduced catalyst.

PrumYJl, 1974, 24, (4), 187-190

Selective Oxidation of Olefins over Noble Metal Catalysts. IV. Oxidative Dehydro- genation of 1-Butene-over Platinum Group Metals and Modified Palladium Catalysts. V. Mechanism of Palladium-catalysed Oxy- chlorination of Propylene €1. TAKASHIMA, K. FUJIMOTO and T. KUNUGI, NipponKagakuKaishi, 1974, (3), 428-433,434-438 Studies of catalysts during oxidative dehydrogenation of I-butene showed that catalytic activity decreased in the order: Pd> R h > P t > Ir> Ru. The effects of additives on Pd catalysis and on the mechanism of oxycholorination of propylene over supported Pd was studied.

Oxidation of Carbon Monoxide on Palladium R. L. PARK and D. G. SCHREINER,~ . Vamum Sci. Technol., 1974, 11, (I), 248 The reaction of CO with absorbed 0, on a Pd surface at room temperature to evolve CO, was studied by infrared absorption methods.

Preparing Finely Dispersed Palladium Parti- cles Y. T. CHEN and s. SRINIVASAN, Abstr. Papers, 167th Natl. Mtg., Am. Chem. Soc., 1974 (Mar.- Apr.), COLL 82 Studies were made to prepare Pd particles with an average diameter <50 A by using electroless deposition techniques and the effects of stirring, temperature, time of reaction, and surfactant on the morphological characteristics of Pd particles were examined. The results showed that ultrasonic stirring of the solution and temperature of 10°C are the best conditions for a high rate of nucleation.

On the Mechanism of Conversion of Hydro- carbons with Water Vapour on Rhodium/ Alumina Catalyst G . L. RABINOVICH and v. N. MOZHAIKO Neftekhimiya, 1974, 14, (2), 215-21g The conversion of hydrocarbons with H,O vapour over Rh/Al,O, includes the adsorption

and activation of H,O on the hydrophilic surface of the A1,0, support. The activity of Rh/a-Al,O, in toluene dealkylation and in n-heptane conversion with H20 vapour increases when y-Al,O, is added to the catalyst.

Asymmetric Ruthenium Catalyst Mudified by Optically Active Amino Acids

NEUPOKOBV, T. A. ANTONOVA and s. E. TERNOVSKII, Izv. Akad. Nauk S.S.S.R., Ser. Khim., 1974,

Studies of the asymmetric hydrogenation of ethyl acetoacetate on skeleton Ru and 5$t0 RujSiO, catalysts modified by optically active amino acids showed that the greatest yield was obtained using catalyst modified with L-glutamic acid. The yield of ethyl-j3-oxybutyrate was related to the p H and temperature of the modified catalyst. Optimum p H is close to the isoelectric point of the amino acids.

Hydrogenation of Carbon Dioxide over a Supported Ruthenium Catalyst F. I,. KESTER, Abstr. Papers, 167th Natl. Mtg., Am. Chem. Sac., 1974, (Mar.-Apr.), FUEL 17 The recent data on reaction rates for the hydrogenation of CO, over 0.5";o Ru/Al,O, were analysed and interpreted to proceed in steps to CO and then to CH,. The rate constant and activation energy were given along with adsorption constants for CO, CO, and H,O.

Catalytic Properties of Metal Phosphides. I. Qualitative Assay of Catalytic Properties E. L. MUETTERTIES and J. c. S A U E R , ~ . Am. Chem.

Preparation studies of transition metal phosphides / Alto, and qualitative comparison of these phosphides with Pd, Pt, Rh, Ru showed that with Ru phosphide surfaces, there was a relatively selective interaction of CzHa and H, to give

E. I. KLABUNOVSKII, N. I?. SOKOLOVA, V. I.

('3, 136 1-1364

Sac., 1974396, (II)i 3410-3415

CzH4.

Recent Developments in Platinum Metal Catalyst Systems G. J. K. ACRES, A. J. BIRD and P . J. DAVIDSON, Chem. Engr., 1974, (283, March), 145-148, 157 Activity, selectivity and life of Pd, Pt, Ir, Os, Rh, and Ru catalysts were studied during hydrogenation of nitrobenzene at I atm, of benzoic acid at 100 atm, of dinitrotoluene at 2-15 atm, and the reactor design for catalytic exhaust emission control was discussed.

HOMOGENEOUS CATALYSIS Hydrogenation of Unsaturated Hydrocarbons in the Presence of Pt-Sn(I1) Complexes L. KH. FREIDLIN, N. v. BORUNOVA and YA. G. MuKHTAROV, Neftekhimiya, 1974,14, (2), 171-173 The rate and direction of hydrogenation and of


C = C bondItransfer in unsaturated hydrocarbons in thelpresence of Pt-Sn(I1) complexes depends on the structure of the reactants and on the composition of the active complexes. The rate of hydrogenation of allxlbenzene and of pentene-1 passes through a maximum when pHI=o.5 atm. Pt-Sn(I1) complexes are most active when Sn/Pt = 12. The activity is closely related to the concentration of both components in the solution.

Kinetics and Mechanism of the Homogeneous Hydrogenation of Cyclohexene and of Sulpholene-3 in the Presence of a Reduced PtCl,(H ,O) [P(C,H,) J Complex V. F. ODYAKOV and K. I. MATVEEV,Kinet.Kataliz, 1974,15, (z), 349-353 The limiting stage in hydrogenation of cyclohexene and of sulpholene-3 in the presence of reduced PtClz(HZO)[P(C,HJ3] is either the formation or the decomposition of Pt alkyl hydride complexes with the formation of saturated compounds. Kinetic studies showed that the constant K1 of formation of LPt-olefin complexes for sulpholene-3 is less than for cyclohexene despite the greater electronegative nature of the substituents in sulpholene-3.

Organic Synthesis by Means of Noble Metal Compounds. LI. Palladium-catalysed Addi- tion of Butadiene to Nitroalkanes T. MITSWASU and J. TSUJI, Tetrahedron, 1974, 30,

Butadiene reacts with nitroalkanes in the presence of PPha complexes of Pd. a-Hydrogen atoms of nitroalkanes are displaced with 2, 7-octadienyl groups to give nitroolefins, which may be reduced to give novel long chain amines having a primary amino group at the middle of the carbon chain. XCII. Palladium Catalysed Hydrosilylation of Monoenes and Conjugated Dienes J. TSUJI, M. HARA and K. OHNO, Tetrahedron, 1974,

Pd compounds and metallic Pd combined with phosphine are active catalysts for the selective hydrosylation of terminal olefins. Butadiene and trichlorosilane give a I :I adduct, and trimethyl- silane gives a I :2 adduct. Special features of the Pd-catalysed hydrosylation reactions are discussed.

(7)J 83r-834

30, (I4)J 2143-2146

Palladium-promoted Addition of Amines to Isolated Double Bonds B. AKERMARK, J. E. BACKVALL, L. s. HEGEDUS, K. ZETTERBERG, K. SI I~LA-HANSEN and K. SJOBERG, J. Organometal. Chaw., 1974,72, (I), 127-138 Pd(I1) complexes are able to promote amination of terminal olefins, to give, after reduction, high yields of amines. Internal olefins may also be aminated, but with poorer yields; cyclohexene and

cyclooctene react particularly slowly. Means of avoiding formation of bis-(amine)-Pd complexes are discussed. Preliminary mechanistic studies show that three moles of amine are required per mole of Pd to ensure good yields.

An Efficient and Selective Monohydrido Rhodium(1) Homogeneous Hydrogenation Catalyst Containing a Cyclic Phosphine

HUI, Can.3. Chem., 1974,52, (51,775-781 D. E. BUDD, D. G. HOLAH, A. N. HUGHES and B. C.

The preparation of RhH(DBP),, DBP being a dibenzophosphole derivative, is described. This Rh complex is a highly effective and selective catalyst for the homogeneous hydrogenation of terminal olefins. Kinetic and mechanistic data for the hydrogenation of I-hexene are given.

Study of the Reactions of Hydrogenation and Isomerisation of Olefins in the Presence of Catalytic Systems Containing Complexes of Rhodium with Triphenylphosphine and Di- methylsulphoxide

B. L. LEBEDEVA and B. L. KHUSID, Izv. Akad. Nauk S.S.S.R., Ser.Khim., 1974, (6), 1325-1330 The introduction of the DMSO ligand into (Ph,P),RhCl with subsequent treatment by NaBH, in DMSO solution increases the catalytic activity of the complex for transfer of terminal C=C bonds and for cis-trans conversion of p- olefins. Splitting of the olefin chains leads to a reduced rate of isomerisation. The rate of isomerisation sharply rises in the presence of H , indicating the intermediate formation of hydrides.

L. KH. FREJDLIN,YU. A. KOPYTTSEV, N. M. NAZAROVA,

Investigation of the Rate and Selectivity of Reduction of Alkylcyclohexanones by 2- Propanol in the Presence of Triplienyl- phosphine Complexes of Ruthenium, Rhodium and Iridium

SHEKOYAN, Ibid., 1330-1334 The rate and selectivity of reduction of 2-, 3- and 4-alkylcyclohexanones by 2-propanol in the presence of Ru, Rh and Ir complexes depend on the type of metal atom, the connected ligands and the position of the alkyl group. Substitution in position 2 decreases the rate of H transfer. RhCl(PPh,), and Rh(NO)Cl(PPh3), catalyse reduction of 3- and 4-alkylcyclohexanones to form mainly the thermodynamically less stable alkylcyclohexanols while RuCI,(PPh&, HRu(C0)Cl

Rh(MezSO)C1(PPh3),, and Rh(OH)(CO)(PPh,), direct the process towards forming the thermodynamically more stable alkylcyclohexanols. Those complexes not containing CO groups catalyse reduction of 2-alkylcyclohexanone to form mainly the thermodynamically less stable cis-2-alkylcyclohexanol.

V. Z. SHARE, L. KH. FREIDLIN, V. N. KRUTII and I. S.

(PPh3)3~ Ir(CO)W'h&z, Rh(CO)Cl(PPh,)z,

Platinum Metals Rev., 1974, 18, (4), I 54

Reactive Transition Metal Dinitrosyl Com- plexes. Synthetic Uses and Catalytic Properties B. L. HAYMORE and j. A. IBERS,J. Am. Chem. soc.,

Series of reactions and experiments of Rh, Ir dinitrosyl complexes showed that they are very reactive and that the conversion of NO and CO into NOa and CO, is catalytic and general in scope. The reactions implicate transition metal dinitrosyls as the important species in the reduction of NO by CO.

Photochemical Activation of IrCl(C0) (PPh,) Hydrogenation Catalysts W. STROHMEIER and G. CSONTOS, J . Organometal. Chem., 1974,72, (2),277--282 Under weak U.V. radiation the activity of IrCl(CO)(PPh,), as a hydrogenation catalyst is increased approximately fortyfold. Reactive intermediates are formed in both reversible and irreversible steps. Once the active intermediate compound has been produced in the irreversible step, rapid hydrogenation proceeds even in the absence of radiation.

Catalytic Action of Ruthenium Compounds in the Process of Styrene Oxidation M. E. PUDEL’ and z. K. MAizUs, Neftekhimiya, 1974,

RuCl ,(PPh,), additions catalyse the oxidation of styrene and increase the yield of styrene oxide. The styrene 0xide:benzaldehyde concentration ratio rises with increased temperature and decreased 0, concentration in the oxidising gas.

On the Catalytic Properties of Blue Com- plexes of Ruthenium L. KH. FREIDLIN, E. F. LITVIN and K. G. KARIMOV, Izv. Akad. Nauk S.S.S.R., Ser. Khirn., 1974, (4),

19743 96, (101, 3325-3327

14, (311 412-416

821-824 Blue Ru reducing presence promote

chloride complexes were produced by Ru(IV) compounds with Hz in the of Ru black. Ru chloride complexes C = C bond migration and cis-trans

NEW PATENTS CHEMICAL COMPOUNDS

Palladium Acetylacetonate of Low Chlorine Content BAYER A. G . U.S. Patent 3,787,462 A high purity Pd acetylacetonate is obtained by precipitating a Pd compound from an aqueous alkali PdC1, solution with an alkali metal hydroxide, converting the precipitate to the Pd acetylacetonate with acetylacetone and washing and drying the acetonate.

isomerisation of olefins not catalysed in hydrogenation. These complexes catalyse selective hydrogenation and isomerisation of dienes.

Stoicheiometric Hydrogenation of Olefins Using HRiiCI(PPh,), and Formation of an ortho-Metallated Ruthenium(I1) Complex

J. Chem. Soc., Chem. Commun., 1974, (II), 439-440 Studies of stoicheiometric hydrogenation of olefins using HRuCl(PPh,), in the absence of Hz showed formation of the dimer [(Ph3P)C1Ru(o-C8H, PPh,)], which reacted with H, and HCl, to yield catalytically important bisphosphine complexes RuXCI(PPh,), (X=H, Cl).

B. R. JAMES, L. D. MARKHAM and D. K . W. WANG,

GLASS TECHNOLOGY A New Design of Nozzle for Bubbling Glass T. M. GALIEVA and S. I. MATYUSHA, StekIoKeram.,

The nozzle of the glass bubbling tube is covered with Pt, both in the old design and in the new design, which has wider bores in the corundum twin-channel tubing.

‘974, (5)J IGr7

ELECTRICAL AND ELECTRONIC ENGINEERING Reaction Rates for Pt on GaAs

APPl. PhYS. Lett., 1974, 24, (S), 355-357 D. J. COLEMAN, W. R. WISSEMAN and D. W. SHAW,

The rate at which GaAs reacts with Pt was determined at 300-40Ooc. The amount of GaAs reacted was determined by measurement of the movement of the original Pt Schottky-barrier contact into the GaAs. The amount of GaAs reacted is a function of annealing time at several different temperatures. The reaction follows a parabolic rate law with activation energy of 1.6eV. Some changes in the electrical characteristics of the Schottky barrier are observed.

Compounds of Ruthenium JOHNSON MATTHEY & CO. LTD.

u.s. Patent 3,793,355 A composition of matter has the general formula MM‘M”XA,LL’L” where M, M and M” are the same or different transition metals selected from the second or third series of the periodic table; X is 0, S, N, P or B; A is an anionic ele- ment or group and L, L’ or L” are neutral or anionic ligands. A preferred compound is Ru,O(OCOMe),(PPh,), and generally the Ru carboxylates are used as homogeneous catalysts.

Platinum Metals Rev., 1974, 18, (4),155-158 155

ELECTRODEPOSITION AND SURFACE COATINGS Electrodeposition of Ruthenium

U.S. Patent 3,793,162 An electroplating bath and process for electroplating Ru is prepared by dissolving RU,N(OH)~ nH,O in H,SO, or H,NSO,H and adjusting the pH to 4 or less.

INTERNATIONAL NICKEL CO. INC.

Electroless Plating

In an electroless plating method Pd or Au is deposited on a substrate in vacuum and then the substrate is electrolessly plated using the previously dcposited Pd or Au as the catalyst.

TORAY INDUSTRIES INC. U.S. Patent 3,801,368

LABORATORY APPARATUS AND TECHNIQUE pH Meter Electrodes

British Patents 1,353,209, 1,353,210 A reference electrode, including a Ag wire coated with AgCl is positioned within an insulating tube the opposite end of which is surrounded with Pd coated with Pd oxide.

GENERAL ELECTRIC CO.

HETEROGENEOUS CATALYSIS Dehydrogenation Catalyst

British Patent 1,351,393 A dehydrogenation catalyst is produced by impregnating A1,0, with a solution containing a Ge compound, a Pt group metal compound, a halide and an alkali metal compound. The product is steamed to reduce the halogen content to less than 0.1::;. The impregnated and steamed support is dry heated at 204-649"C7 reduced and sulphided. Pt and Pd are preferred.

UNIVERSAL OIL PRODUCTS CO.

Aminocyclohexyl Compound Production

British Patent 1,351,487 Bis(aminocyclohexy1)alkanes or ethers are produced by hydrogenation or the corresponding aminophenyl compounds over a suspended catalyst which may be Ru.

BADISCHE ANILIN- & SODA-FABRIK A. G.

Hydroreforming Catalysts

British Patent 1,351,562 A new hydroreforming catalyst consists of a refractory inorganic oxide support, e.g. A1,0,, having a surface area of more than 15 m3/g and

CIE. FRANCAISE DE RAFFINAGE


a pore volume of more than 0.1 cms/g carrying 0.02-2~/0 Pt (preferably 0.1-0.7*/,), 0.02-296 I r (preferably 0.1-0.70/~) and 0.02-2y0 Sn.

Hydrogenation Catalysts DU PONT OF CANADA LTD. British Patent 1,352,737 Butyrolactam and valerolactam respectively are obtained by hydrogenation of succinimide and glutarimide in the presence of a catalyst, e.g. Pt, Pd or Re, optionally supported.

Preparation of Rhodium-containing Catalyst

British Patent 1,354,778 Rh containing catalyst, suitable for the ring- opening and saturation of cyclic hydrocarbons, is produced by mixing SiO, and a Rh-cation- containing solution so that ion-exchange takes place, removing the liquid and drying the ion- exchanged SO,.

Platinum-Lead Catalysts ASAHI KASEI K.K.K. British Patent 1,356,464 Pt-Pb catalysts supported on a carrier such as A1,0, are regenerated by applying HCl and/or HNO, solutions and calcining the catalysts. The catalysts may contain further metals, among them Ag, Au and Pt group metals.

Catalytic Reforming BRITISH PETROLEUM CO. LTD. British Patent 1,356,634 Hydrocarbon reforming is catalysed by a supported mixture of a Pt group metal and As. The support, such as A1,0,, must be free from alkali and alkaline earth metals. The Pt (or other Pt- group metal) content is O . O I - ~ " / ~ and the As content is 5-35 at.O/o of the Pt+As content.

Catalytic Reforming

British Patent 1,359,728 A relatively lean octane hydrocarbon fraction is reformed using a supported Pt-Re catalyst in two stages with water excluded in the first, but not the second stage.

Methanation of Carbon Monoxide and Carbon Dioxide

U.S. Patent 3,787,468 The preferential, selective and sequential methanation for reaction of gases containing CO or CO, in the presence of H,, using catalysts of Rh and Ru metals or alloys with Pt is improved with W oxide. Typically Ru and WOx in a 85:15 ratio or Pt, Rh and WO, in a 42.5:42.5:15 ratio are used. x is unknown.

Selective Hydrogenation of Hydrocarbons P. BERNUSSET U.S. Patent 3,787,515 Unsaturated impurities in the purification of

SHELL INTERNATIONALE RESEARCH MIJ. N.V.

UNIVERSAL OIL PRODUCTS GO.

INSTITUTE OF GAS TECHNOLOGY

156

ethylenic gases are removed by selective hydrogenation with a Pd catalyst having an addition of V as a promoter.

Preparation of Catalysts

US. Patent 3,789,020 A catalyst is formed from a mixture of one or more Group VIII metals with an optional Group 1B metal, e.g. Pt and Cu, deposited on particles of a support such as Also,, mixed with further un- coated particles of support.

Reforming Catalyst PHILLIPS PETROLEUM CO. U.S. Patent 3,789,024 An improved catalyst has refractory-supported Pt promoted with both I r and Ga and exhibits increased activity and selectivity characteristics for the dehydrocyclisation and reforming of hydrocarbons. In one example, A1,0, promoted with Pt, Ir and Ga is used in the conversion of n- heptane to benzene and toluene with substantial conversion at high selectivity.

Tetrametallic Hydrocarbon Conversion Catalyst

U.S. Patent 3,790,473 A catalytic composite contains Pt or Pd, Ir, Re and Sn on a porous carrier material. It is used mainly in the conversion of hydrocarbons, particularly in the reforming of a gasoline fraction. A specific example of this catalytic composite is a combination of Pt, Ir, Re, Sn and a halogen with A1,0, carrier material in amounts to supply approximately O.OI-Z?& Pt, O.OI-Z:& Ir, 0.01-2'6 Re, o.01-50/; Sn and 0.1-3.5y~ halogen.

ESSO RESEARCH & ENGINEERING CO.

UNIVERSAL OIL PRODUCTS CO.

Preparation of Organic Dinitriles

A process for preparing organic dinitriles by the dimerisation of acrylonitrile consists of reacting acrylonitrile with H, in a gaseous phase at 1oo-450"C under a total pressure of 1-20 atm by using as catalyst Ru metal or a Ru compound reducible to Ru metal under reaction conditions. The catalytic activity of the catalyst can be increased by addition of an alkali metal hydroxide or a mixture of a halide of Nil Cr, Mo or W with an organic P compound.

Combination Reforming Process

U.S. Patent 3,791,961 A conventional naphthene dehydrogenation catalyst, such as a Pt-halogen/Al,O, catalyst, is used in the initial zone or reactor in a catalytic reforming process; the tail zone or reactor contains a supported Group VIII polymetallic catalyst with platinum as one of the metallic components. In a preferred embodiment, the tail zone contains a Pt-Ir catalyst on a porous support such as A1,03.

KURASHIKI RAYON CO. LTD. U.S. Patent 3,790,617

ESSO RESEARCH & ENGINEERING GO.

Preparation of Acrylic and Methacrylic Acids

U S . Patent 3,792,086 Acrylic or methacrylic acids are selectively produced in a single step process involving the vapour phase oxidation of propylene or isobutylene, respectively, at temperatures of up to 300°C and in the presence of a catalyst composition containing H,PO, and Pd metal.

Reforming Catalyst

U.S. Patent 3,793,232 A catalyst for the conversion of hydrocarbons, particularly for reforming reactions, has A1 ,03 base supporting on the following metals: 0.005- I",; Pt, o.oo5-1?b Ir and 0.05-30/; T1 or In. Optionally the catalyst may further contain from O.I-IO~; of a halogen and up to IoU~, of Zn.

Olefin Hydroisomerisation Process

US. Patent 3,796,766 Olefins are hydroisomerised utilising a catalytic composite containing a Pt group component and a Group IVA metallic component combined with a carrier material of A1,0, and a finely divided crystalline aluminosilicate such as mordenite. The active metals may be Pt and Ge.

Reforming with Platinum and Tantalum or Niobium Catalyst

U.S. Patent 3,799,867 A catalyst of o.o~--j"C Pt on a refractory support also contains 0.01-59: of Ta or Nb. The support is preferably A1,0, which may contain halogen. The T a or Nb may be added at any convenient stage in the catalyst preparation, including adding it as a chloride or fluoride during the preparation of the support.

Multimetal Powder Alloy Catalyst STAMICARBON N.V. Dutch Appl. 73.16236 An alloy is formed from a complex of two metals or their compounds by reduction in situ of particles on a support. Thus Ge and Pd salts can be deposited on A1,0, and reduced to form a Ge-Pd alloy.

NATIONAL DISTILLERS & CHEMICALS CORP.

STE. FRANCAISE DES PRODUITS POUR CATALYSE

UNIVERSAL OIL PRODUCTS GO.

BRITISH PETROLEUM CO. LTD.

HOMOGENEOUS CATALYSIS Hydroformylation and Hydrogenation Catalysts

British Patent 1,357,735 Gaseous olefins are reacted with H, and CO (or H, alone) in the absence of solvent but in the presence of a liquid As or Sb-containing stabilising donor ligand using as catalyst a hydrido

JOHNSON MATTHEY & CO. LTD.


carbonyl complex of Rh including an As- or Sb-containing ligand. An example of the catalyst is RhH(CO),[AsPh,].

Formylindane Prodtiction

British Patent 1,358,081 I- and 2-formylindanes are produced by the hydroformylation of indene in the presence of a Rh carbonyl complex such as Rh(CO)(PPh,),Cl.

Process for Producing Acyloxydodecatrienes

U.S. Patent 3,789,066 Acyloxydodacatrienes are produced by reacting an octatriene, a butadiene and a carboxylic acid in the presence of a catalytic amount of a divalent Pd compound selected from organic acid salts of Pd (II), chelate complexes of Pd (11) and Pd nitrate.

Ole fin Isomerisation and/or Hydrogenation PHILLIPS PETROLEUM co. U.S. Patent 3,793,257 Ru hydride complexes containing tertiary phosphine, arsine, or stibine ligands are employed as catalysts for isomerisation andjor hydrogenation of olefins. Terminally unsaturated olefins are selectively isomerised to internally unsaturated olefins by complexes that contain N or NH,, e.g. (tribenzyl arsine),RuH,(NH,).

Rhodium Catalysts

U.S. Patent 3,794,671 Nonhalogen or pseudo-halogen coordination complexes of Rh(1) containing a stabilising donor ligand are made by adding a compound which acts as a stabilising donor ligand to a solution of Rh (11) carboxylate protonated by an acid. The complexes with arsines, phosphines, etc, are useful catalysts. One example is Rh(0COMe)

BADISCHE ANILIN- & SODA-FABRIK A.G.

MITSWBISHI CHEMICAL INDUSTRIES LTD.

JOHNSON MATTHEY & CO. LTD.

(PPh,),.

Bidentate Rhodium Cordinates

U.S. Patent 3,798,241 Bidentate coordinates of the formulaR,X-R’-YR,, in which X and Y are P, As, Sb or N, R is a hydrocarbon group containing an asymmetric C atom and the R groups are hydrocarbon radicals, may be associated with Rh complexes to yield hydrogenation catalysts useful in asymmetric synthesis, e.g. in the synthesis of optically active aminoacids or amines. For example Rh,Cl,(cyclooctene), may be used with a di- phosphinotartrate Ph,PCH,-CH(0Me)-CR,

Producing Acyloxydodecatrienes

U.S. Patent 3,798,260 Acyloxydodecatriene is produced by reacting an octatriene, butadiene and a carboxylic acid in the

INSTITUT FRANCAIS DU PETROLE

PPh,.

MITSUBISHI CHEMICALS INDUSTRIES LTD.

presence of a catalytic amount of Pd or Pd compound and an amine.

CHEMICAL TECHNOLOGY Layered Electrode METALLGESELLSCHAFT A.G. U. s. Patent 3,788,968 An electrode, especially useful as an anode in the electrolysis of alkali metal chlorides, includes a graphite body, a first surface covering of a hard ceramic such as T i carbide or T i nitride and at least one metal and/or metal oxide of the Pt- group and a second oxide coating which is electrically porous and resistant to the electrolysis conditions. Ru/Ru oxide are used in one example.

Matrix Electrode

Finely divided RuO, serves as an efficient and long-lived electrocatalyst when dispersed in a polymer matrix chemically and mechanically intert to an electrolyte. When applied to a substrate, generally an electrically conductive substrate, an electrode, particularly suited for use as an anode at which 0, is evolved, is obtained. A coating of polyvinylidene fluoride containing RuO, having a particle size of less than 0.1 micron on a T i substrate is one example.

DIAMOND SHAMROCK CORP. U.S. Patent 3,798,063

ELECTRICAL AND ELECTRONIC ENGINEERING Semiconductor Contacts R.C.A. CORP. British Patent 1353,975 A semiconductor surface is sputter etched in the presence of a backing plate so that the two surfaces provide the components of an alloy layer. For example a silicon semiconductor and a Pt backing plate become coated with Pt silicide.

Ceramic Capacitors Metallisation

U.S. Patent 3,798,516 Metallising compositions with alloys of three or more metals are used in making ceramic capacitor electrodes. The alloys have a critical surface area. The metals of the alloy are Pd, Pt and Au. The metallising compositions are especially suitable for producing capacitors on ceramic dielectric substrates which contain Bip(SnO,),.

E.I. DU PONT DE NEMOURS & CO.

TEMPERATURE MEASUREMENT Thermocouple UNITED STATES STEEL cow. British Patent 1,352,743 A conventional Pt thermocouple forms part of an electrolytic apparatus for the determination of oxygen in e.g. molten steel.


Page Ahramova, L. 1. 35 Acres, G. J. K. 152, 153 Akermark, B. I54 Alberts, H. L. 149 Artman, D. 74 Atkins, L. M. 36 Avksent’ev, V. V. 78 Avramenko. M. V. 113

Backvall, J. E. 154 Baahdadi. A. 74

AUTHOR INDEX

Baser, J.’C. Baker, R. T. K. Baldncci, G. Baranowski, B. Barber, C. R. Barlow, I. C. Bartholomew, C. Bartlett, N. Beck, A. Beille, J. Belikov, V. M. Bellstedt, E. Benson, J. E. Berch, M. L. Bergner, D. Bernard, V. B. Bernasconi, J. Berndt, U. Bianchi, M. Biesterhos, J. W.

40 130 150 149 148 26

H. 57 16

110 149 78 79 39 37 36 36

110 29 37

. M. 114 Bird, A. J. 153 Blurn, J. 114 Boganov, A. M. 78 Boronin, V. S. 109, 152 Borunova, N. V. 153 Bourne, A. A. 46 Bragin, 0. V. 113 Breedis, J. F. 109 Breusova-Baidala,

Yu. G. 150. 151 Brooks, C. R. 109 Briiesch, P. 37 110 Bruner, H. Buckel, W. Budd, D. E. Burch, R. Burnett, R. L. Buyanova, N. E. Bystrov, V. I.

40 35

154 74 77 39 78

Cahen, D. 151 Cahn, R. W. 74 Cauziani, F. 1 I4 Cerveny, L. 153 Chamherland, B. L. 151 Chandrasekharaiah,

M. S . 150 Chen, H. S. 74

Chen, Y. T. Cleare, M. J. Cockayne, B. Coleman, D. J. Conrad, H. Contijoch, 0. P. Cooper, B. J. Copley, G. J. Cox, J. T. Csontos, G.

Page 153 122 86

155 109 38

78, 152 41 15

I55

Dalla Betta, R. A. Damen, J. P. &I. Dauison, A. Day, J. G. Demidovich, G. V. De Minjer, C. H. De Renzi, A. De Ribaupierre, Y. Deutsch, R. Dini, P. Dones, D. Dorogochinskaya, V.

Uortbudak, T. Duhinin, E. L. Duhaj, P. Dumont, W. Dutreix, A.

51 15 37 46 80 76 36

149 75 38 38

A. 112 74 74

150 80 81

Eberson, L. 40 Edshammar, L.-E. 75 Eichler, A. 35 Ellner, M. 35 Erdmann, B. 29 Erivanskaya, L. A.

40, 152 Ertl, G. 109 Evdokimova, 0.1. 150 Evnin, A. B. 39

Fahey, D. R. Falkenhurg, G. Fedorov, G. V. Feldstein, N. Fenton, D. M. Ferro, R. Figureas, F.

41 27 35 76

40, 113 109 39

Finkel’shtein, E. Sh. 78 Finley, A. 14 Firth, J. G. 152 Flanagan, T. B. 74 Pliikiger, R. 35 Pokin, M. N. 111 Fomichev, Yu. V.

38,77, 151 Fowler, L. 41

1 TO VOLUME

Page Francis, N. €3. 74 Frankel, E. N. 80 Freidlin, L. Kh. 40, 80,

113, 153, 154, 155 Friedrich, J. P. 79 Fries, R. W. 114 Fujimoto, K. 153 Fujiwara, Y. 40

Gale, G. R. 36 Galieva, T. M. 155

Garnett, J. L. 36 Gennis, M. 76 Gentry, S. J. 152

Gandhi, H. S. 2

Geserich, H. P. 37 Ghorhel, A. 77 Gingerich, K. A. 11 1 Given, R. M. 41 Giidecke, T. 35 Gogol’, N. A. 112 Golyanitskaya, I. N. 151 Gomes-Gonzalez, L. 40 Gomez, R. 39 Graves, B. B. 38 Greenaway, F. 104 Griffith, W. P. 94 Grishina, T. M. 77 Gryaznov, Y. M. 79 Gryzunov, V. I. 75 Gnshchin, V. I. 110 GUtZOW, 1. 109 Gyul’maliev, A. M.

77, 18

Haddad, Y. M. Y. 114 Hall, J. R. I10 Halpern, J. 41 Hara, M. 154 Harhord, N. H. 97 Harper, J. M. E. 11 1 Hartley, F. R. 36

Haymore, B. L. 155 Henbest, H. B. 114 Henry, P. M. 40,XO Hertel, P. 149 Hidai, H. 31

Holah, D. G. 154 Holtzman, A. 11 1 , 154 Horanyi, G. 38 Huang, F. 114 Hufner, S. 109 Hughes, T. R. 17 Hwang, H. S. 39

Hass, G. 75

Hirsch, J. A. 79

Page Iandelli, A. 75 Ihers, J. A. 151. 155 Il’in, V. F. 111 Irani, R. S. 14 Itagaki, T. 150 Ivan’kovich, E. F, 76 Iwasaki, H. 35

Jackson, J. S. Jaklevic, R. C. James, B. R. Jangg, G. Johnson, J. W. Jones, D. J. Jones, T. P. Jonker, H. D. Josey, A. D.

129 I50

80, 155 74 76 79 91 15

113

Kamminga, W. 15

Katzer, J. R. 151 Kauffman, G. B. 142 Keller, C. 29 Kester, F. L. 1 13, 153 Khairullina, R. 2. 114 Khalaff, K. 150 Khan, H. R. 35

Kaplan, J. H. 111

Khelkovskaya-Sergeeva, E. G. 113

Khrapova, E. V. 79 Kmoshita, K. 78 Klahunovskii, E. I. 153 Klapwijk, P. 78 Kleykamp, H. 110 Klimisch, R. L. 57, 79 Kobylinski, T. P. 38 Kohlhaas, R. 36 Kokura, M. 31 Kolaczkowski, A. 152 Kolosov, M. G. 114 Kopyttsev, Yu. A.

40, 113, 154 Kowalczyk, L. S. 58 Kozlov, N. S. 39. 76 Kozlova, L. M. 11 2

Kraus, M. 40 Kuhalla, M. 149 Knhicki, J. 152 Kuindersma, P. I. 37 Kuprina, V. V. 36 Kurchatkina, T. V.

3 8 , l l Kuznetsova, L. I. 11 3

Krahichler, T. 74

Lamparter, P. 14 Lange, R. C. 31 Latov, V. K. 78

Platini~~Metal.~Re.z,., 1974, 18, (4), 159-164 159

18

Page Lazarev, M. Ya. 76 Leary, K. 75 Levin, D. Z. 112 Levitskii, 1. I. 38, 11 1 Liederman, D. 57 List, G. R. 79 Litvin, E. F. 112, 155 Logacheva, L. I. 77, 150 Loginov, S. V. 150 Lorberth, J. 110 Luk’yanova, Z. V.

112, 152 Lunde, P. J. 113 L’YOV, A. I,. 35, 36 Lyons, J . E. 80 Lyubarskii, G. D. 39

Minero, R. M. Minot, M. J. Mitsuyasu, T. Moers, F. G. Morgan, C. R. Morrison, J. D. Mozhaiko, V. N. Mrafko, P. Muetterties, E. L. Muir, K. W. Murabayashi, M. Muratova. R. G .

McArthur, D. P. 57 MeDaniel, C. L. 11 1

Makarova, N. G. 11 1 Malm, D. L. 76, 150 Mal’tsev, A. N. 112 Malysheva, L. A. 35, 36 Manankova, G. S. 76 Manchester, F. D. 149 Manuszewski, R. C. 36 Marazzd, R. 109 Marhoul, A. 153 Marinow, M. 109 Markham, L. D. 80,155 Martinyuk, G. A. 76 Martynyuk, M. M. 110 Martynyuk, T. G.

112, 152 Maslyanskii, G. N. 15 1 Matveev, K. I. 11 3, 1 54 Matyusha, S. I. 155 Melville, D. 109 Michalska, Z. M. 65 Minachev, Kh. M.

38, 111 38 75

154

Maizus, Z. K. 155

Nametkin, N. S . Nicol, K. J. Nieuwstad, T. J. Notton, J. H. F. Novak, M.

110 77 41

153 150 153 36

110 114

78 36 78

I30 38

Page Odyakov, V. F . 113,154 Olivei. A. 149

PaaI, Z. Paiaro, G. Palenzona, A. Pampillo, C. A. Panchenkov, G. M. Pandey, R. N. Park, R. L. Parlitz, B. Pasateri, R. J. Pedder, C. Perlstein, J. H. Piacente, V. Pichler, H. Pikart, M. F. Pizzini, S. Poltorak, 0. M. Pospelova, T. A.

Prokofiev, E. P. I’udel’, M. E.

P o u ~ , J.-C.

78 36 75 74 80 40

153 152 151 73 75

150 79 35 37

109 112 80

112 155

Rabinovich, G. L. 79, 153 Rabo, J. A. 39 Ramakrishnan, E. S. 150 Ramesh, B. R. I10 Rand, M. J. 110 Rantel1,A. 111, 151 Rasadkina, E. N. 79

Raub, E. 27 Ravdel’, M. P. 150 Reddy, G. K. N. 110 Regan, M. T. 114

Reinacher, G. 141 Ricodeau, J. A. 109 Rivers, A. D. 41

Robertson, J. M. 15

Ratner, I. D. 77

Reggel, L. 39

Roberts, J. F. 110

Roschel, E. 35 Roth, J. F. 39 Routsis, K. Rubin, J. J. Ryshkin, I. V.

Saillant, R. B. Sarkozy, R. F. Sasson, Y. Sauer, J. C. Sawatzky, G. A. Schafer, H. Schnabel, K.-H. Schreiner, D. G. Schubert, K. SchwartLkoff, G. Searle, G. W.


78 150 114

150 151 1 I4 153 37 75

152 153 150 79 36

Page Seleznev, V. N. 15 1 Selman, G. L. 46 Sen’kov, G. M. 76 Sermon, P. A. 137 Sharf, V. Z. 80,154

Shevtsova, G. A. 40, 152 Shishu, R. C. 58 Shitova, N. B. 113 Shkuryakova, S. P. 81 Shpindler, Kh. 77 Shubochkin, L. K. 110 Simhek, E. 40 Sklyarov, A. V. 78 Smith, G. V. 39 Smol’nik, Yu. E. 39 Snow, D. B. 109

Sokolova, N. P. 153 Sokol’skii, D. V. 112 Solov’eva, 1. V. 1 I2 Somorjai, G. A. 152 Spencer, R. P. 37 Srinivasan, S. 153 Stals, L. 149 Steinwand, P. J. 113 Stille, J. K. 114 Strathdee, G. G. 41 Stritzker, B. 149 Strohmeier, W. 155 Sutyagina, A. A. 15 I Suzuki, K. 37 Swile, G. A. 110

Shelef, M. 2

Sobkowski, J. 1 1 1

Tachigawa, K. Takashima, H. Tatarkina, A. L. Taylor, B. W. Taylor, K. C. Teleshev, A. T. Templeton, D. H. Terpugova, N. A. Tktenyi, P. Thomas, R. B. Togano, K. Tonejc, A. Tonejc, A. M. Topchieva. K. V. Torfs, E. Treiger, L. M. Trimm, D. L. Trump, U’. N. Tsapkov, V. I. Tsintsevich, V. M. Tsuji, J. Tsybulevskii, A. M. Turakulova, A. 0. Turkevieh, J. Tyurenkova, 0. A.

160

75 153 75 38 79 79 75

112 78

130 75

149 149 112 149 79 78 41

110 113 154 39

152 57

112

Page Udal’tsova, E. A. 77 Umezaki, H. 40 Underhill, A. E. 21 Unland, M. L. 38 Urbanovich, I. I. 39 Usov, Yu. N. 38, 11 1 Uzgiris, E. E. 111

Van Dam, J. E. 35 Van Der Boom, P. F. J.

76 Van Gaal, H. L. M. 110 Van Hout, M. J. G. 15 Vasile, M. J. 76 Vatolin, N. A. 74 Vdovin, V. M. 78 Vlasenko, A. G. 78 Vlasov, V. G. 157 Voermans, A. B. 15 Vogel, S. F. 26 Vol’fson, I. S. 39 Voltz, S. E. 77 Von Dahlen, K.-H. 110 Voorhoeve, R. J. H. 57

Wagner, H. Waldron, M. B. Walker, R. Wamhersie, A. Warren, R. Waterstrat, R. M. Webster, D. E. Wender, I. Wertheim, G. K. Westin, L. Wherland, S. Whyman, R. Wieckowski, A. Wisseman, W. R. Wong, C. S. Wosiewitz, U. Wu, C. K. WU. N . 4 .

37 129 36 81

129 36 65 39

109 75 75 37

111 155 41 75 76 35

Yamamoto, H. 37 Yeh, C.-C. 109 Yoda, R. 150 Ynr’ev, B. P. 81 Yvon, K. 35

Zanella, R. 114

Zharkov, B. B. I5 1 Zheligovskaya, N. N.

150, 151

Zubanova, L. G. 38

Zeller, H. R. 110

Zhurba, A. S. 39

SUBJECT INDEX TO VOLUME 18 a= abstract Breath, alcohol detection in

Page 91

Catalysis, Society Meeting, Pt metals papcrs at Catalysts, automobile emission control,

57

production plants for 103 153

complexes, dinitrosyl, a 155 complexes, H transfer from EtOH over, a 114 complexes, IrCI(CO)(PPh,)

photochemical activation of, a 155 complexes, preparation of, a 114 complexes, trans-IrCI(CO)(PPh 2,

hydrogenation of cyclohexadienes with, a 80

oxidative dehydrogenation of 1-butene over, a 153

2-n-butylnaphthalene on, a 40

gem-dimethylcyclobutane on a 113 153

Palladium, activity of, a 112 activity of, selectivity of, a 153 black, macroscopic aggregation in 137 black, stereoselectivity of, a 7s complexes, amination of olefins over, a 154 complexes chlorodimethylsulphoxide,

/somerisation and hydrogenation of lsopentenes on, a 40

complexes, dehdlogenation with NaAIH1(OC1H,0CH8)z on, a 40

complexes, dimerisation of isoprene on, a 113 complexes, phosphine,

hydratocarbonylation of olefins on, a 40 complexes, polymeric, hydrogenation of

olefins by, a 40 complexes, silyl, a 19 comuounds. hvdrosilvlation of olefins

Iridium, activity of, selectivity of, a

Ir/Al,O,, dehydrocyclisation of

IrjC, hydrogenolysis of

Osmium, activity of, selectivity of, a

. _ over, a

dehydrogenation of coal on, a hydrogenation of C-C bonds on, a hydrogenation of dimethylethynylcarbinol

on, a oxidation of CO on, a oxidative carbonvlation on. a

154 39

113

112 78

113 oxidative dehydrogenationof I-butene

over, a 153 particles, preparation of, a I53 PPh, complexes, addition of butadiene to

nitroalkanes on, a 154 reaction of CO on, a 153

on, a 40 olefin reactions on, a 40

Palladium Acetate, aromatic acetoxylation

PdCI2, complexes, isomerisation of heptene-1 with, a 80

80

2-n-butylnaphthalene on, a 152 39 39

decomposition of vinyl alcohol with, a Pd/A120s, dehydrocyclisation of

hydrogenation of CsHaOH on, a Pd surface area of, a preparation of, a 39

2-alkoxycyclohexanols over, a 153

naphthalenes over, a 7s

cyclohcxenes on, a 39

PdjMgO, preparation of, a 39

PdjC, dehydrogenation of

hydrogenation of alkyl-substituted

hydrogenation, racemisation, exchange, double bond migration in substituted

hydrogenolysis of gem-dimethylcyclobutane on, a 113


Catalysts ( c o d ) Page

dimethylethynylcarbinol on, a 112 PdjSiO,, preparation of, a 39 Pd/SiOr-A120,, preparation of, a 39

C,H I on, a 39

dimethylethynylcarbinols on, a 112

Pdipolymer, hydrogenation of

Pd/V,Oj, with Ti, Ru, Pt, or Ir, oxidation of

Pdjzeolite, hydrogenation of

PdO, conversion of andtase to riitilc with, (I Palladium,Phosphide/Al ,O catalytic

Palladium-Ruthenium, heat treatment and

Palladium Sulphate, oxidation of C,H, over, a 1 I3 Platinum, activity of, selectivity of, a 153

black, dehydrocyclisation of hexadienes, hexatrienes on, a 78

black, chemisorption of H , on, a 152 black, hydrogenation of iminoxvi radicals

78

properties of, a 153

activity of, a 79

on, a black, sintering of, Q

catalytic activity on surface of, a complexes, polymeric, hydrogcnation of

olefins by, a complexes, hydrogenation of sulpholene-3

on, a complexes, on nylon, hydrogcnation of

C,H, on, a complexes, PtCl ,(H,O)(PPh,),

hydrogenation of cyclohexenc over, a complexes, Pt-Sn(II), hydrogenation of

unsaturated hydrocarbons over, a complexes, silyl, a exhaust emission, Pb and P poisoning of, a gauze, NH, oxidation on honeycomb, oxidation of CO on metals, coordination compounds of as oxidation of CO on, a oxidation of Ha on, a oxidative dehydrogenation of I-butene

reforming, deactivation by crystal growth

skeleton, H, adsorption by, a Platinum Metals, hydrogenation of

unsaturated hydrocarbons on, a supported homogeneous supported, reduction of NOI by CO,

over, a

in, a

H z on, a Pt/aerosil, Pt(1V) content of, a Pt/AI,03,, alkane disproportionation over, a

aromatisation of isoheptane on, u aromatisation of methylcyclohexane and

n-heptane on, a aromatisation of olefins on, coke

formation in, a Cs-dehydrocyclisation of n-C,H, I on, a chemisorption capacity of, hydrogenation

activity of, a coke formation during reforming of

aromatic and naphthenic hydrocarbons on, a

dehydrocyclisation of n-C6H12 on, a dehydrogenation of cyclohexane on, a hydrogenation of aromatics in je t fuel on, a isocyanate intermediates in NO+CO

oxidation of CO, C3Ha on, a paramagnetic Pt in, a reduction.of NO on, effect of changing

crystallite size, a sintering of, a structure of, a

reaction on, a

112 7s

152

40

113

79

154

153 79

152 130 5s

122 7s

152

153

38 77

114 65

3s 152 77

111

152

77 I7

151

38 76 3s 39

38 77 77

151 17 76

161 161-164

Cat alysts, Pt/Al,Oa ( c o d ) Page with additions of WO,, Sn, aromatisation

of hydrocarbons on, a 151 Y-promoted, dehydrogenation of

cyclohexanegn, a 76 38

11 1 PtjC, dehydrocycbation of n-CsHls on, a

demethylation of2-methylhexane over, a

hydrogenation, racemisation, exchange, double bond migration in substituted cyclohexanes on, a 39

hydrogenolysis of ethylcyclopentanc on, a 78 hydrogcnolysis ofgem-dimethylcyclobutane

on, a 113 molecular sieve, hydrogenation of C3Ho on, a 78 porestructureof, a 152 Pt(1V) content of, a 152

Ptikieselguhr, hydrogenolysis of spiro[2,3]hexaneon, a 78

Pt/polyamide, C.H, hydrogenationover, a 38

Pt(1V)content of, a 152 I52

Pt(1V) content of, a 152

binding substances in hydrocracking on, a 39 decomposition of H *O I on, a 112 inAlzOr,isomerisationofn-CBHl4and

dehydrogenation ofcyclohexaneon, a 39 Pt(1V) content of, a 152

112 Pt(IV) content of, (I 152

152

properties of, a 153

H,O decomposition on, a 112

Pt/SiO,, H20zdecompositionon,a 112

Pt/WO3,H2OZdecomposition on,a 112

Pt/zeolite, acidity of, a 112

Pt/SiO,-AI,O, Pt(1V) content of, a

Pt/ZnO, decomposition of H ,O I on, a

Pt02.4Ca0, N H ?L oxidation on, a Platinum Phosphide/Al,O, catalytic

Pt-Re/Al,O,, hydrogenation of ammatics in

Platinum-Rhodium, gauzes for NHs oxidation, jet fuel on, a 39

deposits on 97 gauzes, N H I oxidation on 130 skeleton, H, adsorption by, a 77

153 complexes, chiral, asymmetric reduction

with, a 80 complexes, chiral phosphine, asymmetric

hydrogenation on, a 41 complexes, codimerisation of styrene with

lower olefins on, a 40 complexes, hydroformylation of

unsaturated fatty acid esters, a 80 complexes, RhCl(PPh 3 I, hydrogenation

and isomerisation of olefins over, a 154 complexes, RhCI(PPh,) hydrogenation

of, a 41 complexes, RhCI(PPh,j 3r hydrogenation

and dehydrogenation of, a 41 complexes, RhCI(PPh3j2, mechanical and

kinetic properties, a 114 complexes, RhCI(PPh3)a, reduction of

ketones by secondary alcohols with, a 80 complexes, PPh,, reduction of

alkylcyclohexanones by 2-propanol over, a I54

dinilrosyl complexes, a 155 oxidative dehydrogenation of 1-butene

RhH, dibenzophosphole derivative,

Rhodium, activity of, selectivity of, a

over, a 153

preparation of, a 154 skeleton, H , adsorption by, a 77

H,O vapour over, a 153 conversion ofn-C-III, on, Q 79 dealkylation of toluene on, a 19 hydroformylation of methyl oleate on, a 79

gerr-dimethylcyclobutane on, a 113

Rh/A120,, conversion of hydrocarbons with

R h E , hydrogenolysis of

Catalysts (cantd) Page Rh/Zr, adsorptionofbutyn-2-diol-l,4 on, a 113 Rhodium Phosphide/Al,O I, catalytic properties

of, a 153 Rhodium-Platinum, gauzes for NH

oxidation, deposits on 97 gauzes, NH oxidation on 130

77 153

complexes, blue, isomerisation of olefins, a 155 complexes, carbonyltriphenylphosphine-

ruthenium(ll), synthesis and propertics of, a 80

complexes. codimerisation of stvrene with

skeleton, H P adsorption by, a Ruthenium, activity of, selectivity of, a

lower olefins on, a 40

of olefins. a 155 complexes, HRuCI(PPh,) hydrogenation

complexes, reactions of, a 114 complexes, RuCl,(CO) ,(PPh,)

hydrogenation of olefins on, a 41 complcxcs, RuC12(PPha),, oxidation of

styrcnc on, a 155 complexes, RuC1l(PPh,)s, reduction of

ketones by secondary alcohols with, a 80 honeycomb, NO, reduction on 2 oxidative dehydrogenation of 1-butene

over, a 153 skeleton, hydrogenation ofethyl

acetoacetate on, a 153 79

153 113 79

79

gem-dirnethylcyclobutane on, a 1 I3

on, a 153 79 78

synthesis of polymethylenc on, Q

reduction of NO on, a

hydrogenolysis of

Ru/Al2O3, hydrogenation of CO, over, a methanation of C O z with He on, a

Ru/C, hydrogenation of substituted 4-chromanones and 4-chromanols on, a

Ru/SiO,, hydrogenation of ethyl acetoacetate

reduction of NO on, a RuO,, conversion of anatase to rutile wth , a Ruthenium-Palladium, hcat treatment and

Ruthenium Phosphide/Al,O,, catalytic activity of, a 79

propertics of, Q 153 Colour, Hazen (Pt-Co) units for, a 76 Crucibles, Iridium, fabrication of 141 Crystal Growing, Pt appdratus for 15

use of Ir in 86

Electrical Contacts, Rh-plated, for dry reed

Electrodeposition of, Palladium, contamination switches 20

during, a 16 Platinum, contamination during, a 16

20 151

Rhodium, for dry reed switches Electrodes, Osmium, H a absorption by, Q

Palladium, anodic dissolution of, in aminochloride electrolytes, a 111

Palladium-Hydrogen, H concentration in, u 11 1 Platinum, absorption and oxidation of

CH,OH on, a 111 breath alcohol sensor with 91 H, absorption by, a 151 platinised, absorption of n-C,H,OH on, a 38 platinised, protein-coated, a 111 porous, a 37

76 76

Platinum-Gold, oxidation of C,Hz on, a Rhodium-Titanium, adsorption of €Iz on, a

Electroless Plating, activation of ABS plastics by PdCI,-SnCI, a 15L

nucleation with PdCll-SnCls on glass before,@ 76 111 rinsing of PdCl,-SnC12 during, a


Page 92

detector 91

Ferrites, production of memory cores Fuel Cells, Pt electrodes in breath alcohol

Glass, bubbling tube, nozzle covered with Pt, a 155 41 drops in contact with Pt, a

Iridium, compounds, CdIr(OH)! and ZnIr(OH),, preparation and characterisation of, a 151

crucibles, fabrication of 141 crucibles, growth of oxide single crystals in 86

109 crystallisation in glasses containing, a electrical resistance of, a 110 Ir-192, radiotherapy using, u 81

Iridium Alloys, Iridium-Platinum, Ir activity in, a 150 Iridium-Tantalum-Nickel, phases, a 36

Iridium Carbide, gaseous IrC2, a 111 Iridium Dioxide, phase relations with Na '0, a 11 1 Izvestiya, Platinum Institute journal 142

Nitric Acid, behaviour of Pt catalysts for manufacturc of 130

97 deposits on Rh-Pt gauzes for

Osmium Tetroxide, properties and applications of 94

Palladium, complexes, carbonyl and carboal koxy, a 37 complexes, cyanoalkyl, a 37

structure of, a 75 crystallisation in glasses, a 109 Debye temperature of, a 35

compounds, [XeF,+]% [PdF,'-], crystal

H2 absorption by, a 109 H diffusion through, a 35,36 X-ray photoemission spectra of, a I09

Palladium Alloys, Palladium-Aluminium, me1 ts, physicochemical properties of, a 74

properties of, a 74

properties of, a 74

Palladium-Antimony, melts, physicochemical

Palladium-Chromium, me1 ts, physicochemical

Palladium-Chromium-Tungsten, sintering,

Palladium-Cobalt, melts, physicochemical

Palladium-Copper, melts, physicochemical

oxidation behaviour of, a 150

properties of, a 74

properties of, a 74 superconducting transition temperature

in, ion implantation, a I49 Palladium-Copper-Silicon, glass, plastic

Palladium-Germanium, phases in, a 150 Palladium-Gold, superconducting transition

temperaturc in, ion implantation, a 149 Palladium-Hafnium, crystal structure of. a 75 Palladium-Hydrogen, diffusion of H in,

activation energies, a 149 H2 lattice gas In, spccific heat of, a 149 pressure-composition isotherms and

74 superconductivity in, a 35. 149

deformation of, a 74

thermodynamics of a-phase of, a

Palladium-Iron, magnetisation and thermal

melts, physicochemical properties of, a e.m.f. of, a 35

properties of, a 74 phases, a 35

expansion in, a 150

74 Palladium:Lead, melts, physicochemical

Palladium-Manganese, coefficient of linear

melts, physicochemical properties of, a 74

Palladium 8110qs (cotrrd) Page Palladium-Manganese-Nichel, coefficlent of

linear expanslon in, a 150 Palladium-Nickel, Debye temperature of, a 35

melts, physicochemical properties of, a 74 Palladium-Rare Earths, cryqtal structure of, a 75

equiatomic ternary phases of, a 109 109 ternary phases of, a 74 Palladium-Rhodium. H I diffuslon In. a

Palladium-Silicon, melts, physicochemical properties of. a 74

structure of, radial distribution function of, N 1 so

Palladium-Silicon-Copper, glass, plastic

Palladium-Silver, H, diffusion through, a 35 deformation of, a

melts, physicochemical properties of, a powders, electrolytic preparation of, a superconducting transition temperature

in, ion implantation, a Palladium-Thorium, crystal structure of, a Palladium-Titanium, corrosion behaviour

of, lz

properties of, a

diffusion in, a Palladium-Tungsten, mcl ts, p hysicochemical

Palladium-Uranium, crystal structure of, a Palladium-Yttrium, crystal structurc of> a

Platinum, apparatus, for crystal growing

74

81

149 75

114 74

74 75 75 15

bronzes, preparation of, physical properties

colour scale in Hazen (Pt-Co) units. a

of, a 151

76 chemisorption of H on, a 109

complexes, antitumour, a 36 complexes, as one-dimensional metallic

conductors 21 comolexes. carbene. metallation of ulienvl - , . .

group in, a 36 complexes, cis-Pt(NH,)rCI,, antitumour, a 37 complexes, cis-PtCNH,) ,CIS, isomerisation

150, 151 of. rate of, antitumour, a complexes, olefin, reaction with amines, a 36 complexes, (PPh,) 2, a 36 complexes, preparation of acetylacetonate, (i 110 complexes, with polynucleotides, a 75 compounds, acidic properties of, a 150 compounds, bromination of K2Pt(CN),, a 75 compounds, K .Pt(CN),Br,. $.3H,O, electrical

conductivity of, a 110 compounds, KnPt(CN)rBr o. 33.3H ,O,

electronic plasma oscillation in, a compounds, K,Pt(CN),Br,. ,.2.3H ,O,

magnetic properties of, a 37 compounds, KzPt(CN)rBro. , .3H20,

optical properties of, a 110 compounds, K,Pt(CN) ,Bro.J.3HI0, optical

conductivity and electrical interaction in, a 37 compounds, K2Pt(CN),Brn. *.3H,O and

K2Pt(CN),Clo.,.3H20, preparation of, a 150 compounds, preparation of Me,PtN3, a 110 compounds, MenPtaOl, a 36 crystallisation in glasses containing, a 109

26 dispersion strengthened, ZCS 46

gauze belts in sintering furnaces 92 glass drops in contact with, a 41

Institute, Izvestiya,of 142 155

refinery expansion 103 sputtered film in computer memory 26

Platinum-Aluminium, non-equilibrium

Platinum-Copper, ordering in, a

31

deposition of, on sapphire and alumina

electrical resistance of, a 110

heat capacity of, a 109

rate of GaAs reaction with, a

Platinum Alloys,

phases, a 149 35, 74, 149


Platinum-Alloys (contrl) Page Platinum-Gold-Niobium, superconductivity,

structure and magnetic susceptibility of, a 35 Platinum-Iridium, Ir activity in, a 150 Platinum-Mercury, structure and solubility

of, n 74 Platinum-Molybtbium, supercond uciing

phases in, a 35 Platinum-Nickel, magnetic properties of, a 149 Platinum-Phosphorus, crystals, a 14 Platinum-Rhodium, gauze belts in sintcring

furnaces 92 Platinum-Silicon, solidification structure of,

thermodynamics of, a 149 111

Platinum Chloride, formation of, from H,PtCI,. a 110 gaseous, a 75

PlatinumDioxide, phasc rclations with N a D , n I 1 1 Platinum Metals, analytical chemistry uses 3 f 104

chemistry, Russian progress in 14

coupled reduction with 29 34

aromatics on, a 36 110

20

126 on 28

with, a 41 110

I10 109 N,,

scattering, a 150 150

Platinum Carbide, gaseous PtC,, a

coordination compounds of 122

research workers, science awards to Platinum Oxide, adsorption of polycyclic

Platinum Silicide, formation of PtSi, a

Reed Switches, Rh contacts in Resistance Thermometers, Pt, NBS Monograph

Pt, reciprocal Kelvin temperature sensor

compounds, RhCI[P(C,H, JJ *, coordinating

crystallisation in glasses, a crystals, growth, magnetic impurity

dissociation energy of, sublimation of, a

thick films, Au-Rh-glass, structural and

Rhodium, cationic complexcs, carbonyl, a

electricalresistance of, a 110

electrical properties of, a 114

Page

diagram of, a 36 Rhodium-lron, crystals, growth, magnetic

impurity scattering, a 150 magnetostriction in, a 109 Rhodium-Palladium, H A diffusion in, a 14

Rhodium Alloys, Rhodium-Chromium, phasc

Rhodium-Platinum, gauzc be1 ts in sintering furnaces 92

Rhodium-Zirconium, superconducting properties of, a

Rustenbnrg, new mining areas for Ruthenium, binder for cemented carbides

complexes, H,Ru(CO)sPPhr, a compounds, [XeF+][RuF,-] and

crystals, deformatton of, a films, optlcal properties of, a reaction with refractory carbides

Ruthenium Alloys, Ruthenium-Magnesium,

Ruthenium-Niobium, conversions in, a Ruthenium-Niobium-Zirconium, conversianc

Ruthenium-Thorium, intermetallic

Ruthenium-Zirconium-Niobium, conversions

[XeF,+][RuF,-1, crystalstructures of, a

phases in, a

in, a

phases in, a

In, a Ruthenium Carbide, gaseous RuC1, a Ruthenium Chloride, RuCl ,.xH ,O, carbonylation

of, a

75 64

129 37

76 109 75 27

75 7 5

75

110

75 111

37

Temperature Measurement, history of 148 Thermistor, electrical/DTA measurements

with, a 38 Thermocouples, Pt:Rh-Pt, physical properties

Of, a 114 thermistor, for electrochemical/DTA

measurements, a 38 weld metal temperature measurement using 73


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