1
CHEM 232 Inorganic Chemistry II (Spring 2006)
Instructor: Wa-Hung Leung (ext. 7360, [email protected]) Office: Rm 4528 (Lift 25/26), Lab: Rm 7141
TAs: (1) Zhang Li ([email protected]) (2) Yi Xiaoyi ([email protected]) (3) Wong Wang Yee ([email protected]) (4) Au Yeung Siu Fung ([email protected])
Class schedule:Lecture: Mon/Wed/Fri, 13:00-13:50 (Rm 2464)Tutorial/example class (4) : To be confirmed
2
Course ContentsCourse Contents1. Coordination Chemistry
Crystal field theorySpectral, magnetic, thermochemcial propertiesCoordination equilibria, chelate effect
2. Organometallic chemistry18 e rule, Carbonyl, olefin, cycloolefin compounds, Organometallic reactions, homogeneous catalysis
3. Main group chemistryHydride and alkyl compoundsElement-element multiple bondsInorganic rings and cagesSilicates and aluminosilicates
3
Assessment scheme
Attendance of lectures and
Quizzes (4) 8% Assignments (2) 2x4% Mid-term exam (~ week 8/9) 38% Final exam 40% Tutorials (4) and others 6%
• Check out a PRS handset!
4
Textbooks and references booksTextbook: “Inorganic Chemistry” by C. E. Housecroft and A. G. Sharpe, Pr
entice Hall (1st ed., 2001; 2nd ed., 2005)
Other suggested readings: Inorganic Chemistry, 3rd ed., by D. F. Shriver et al., OUP (1999).
Basic Inorganic Chemistry, 3rd ed., by F. A. Cotton et al., Wiley (1995)
Concepts and Models of Inorganic Chemistry, 3rd ed., by B. Douglas et al., Wiley (1994)
Inorganic Chemistry, 3rd ed., by G.L. Miessler and D.A. Tarr, Prentice Hall (2004)
5
Websites Course homepage: http://webct.ust.hk
Useful links• Department of Chemistry: http://www-chem.ust.hk/
• Textbook website: www.pearsoned.co.uk/housecroft
• Periodic table: For example,http://www.webelements.com/http://www.rsc.org/is/viselements.htmhttp://pubs.acs.org/cen/80th/elements.html
Conduct in classroom: http://www.ust.hk/vpaao/conduct/con_classroom_Aug04.ppt
6
Coordination Chemistry
• Ref.: Housecroft (Chap. 20), Shriver (Chap. 7)• Introduction: the metals and ligands• Crystal field theory: octahedral, tetrahedral, and squ
are planar geometry• Spectrochemical series (strong/weak field ligands)• Electron configurations: LFSE, LS and HS config.• Spectral, magnetic and thermochemical properties• Coordination equilibria, chelate effect• M.O. diagram of ML6
7
LM
L L
L
L
L
n+
Metal
Ligand
n X
Counter anion
Coordination compounds (metal complexes)
L
ML L
L
MLL L
L
ML
L L
L
L
L MLL
L
L
ML
L L
L
L
L
Tetrahedral
Square planar
Square pyramidal
Trigonal bipyramidal
Octahedral
Common geometry
8
The metalsTransition elements (http://www.rsc.org/is/viselements.htm) Elements with incomplete d shell
(A) Position First/ second/ third row TMs Size decreases down a group Lanthanide contraction (filling of f orbitals)
Sizes of 2nd row and 3rd row TMs are similar
Ion Cr3+ Mo3+ Ru3+ Ir3+
Size/Å (CN = 6) 0.76 0.83 0.82 0.82
9
10
(B) Early/late TMsEarly: on the LHS of the periodic table (e.g. Ti)Late: on the RHS of the periodic table (e.g. Pt)
Usually, for metal complexes Early TM : high metal oxidation state, e.g. Ti(IV), V(V)
(high valent); hard metal ions (binds to hard ligands)
Late TM : low metal oxidation state, e.g. Pt(II), Au(I) (low valent); soft metal ions (binds to soft ligands)
Why?
11
Atomic number
Atomic radius
Ti
Cu
12
Atomic number
IE
Ti
Cu
13
14
Ligands
(A) Charge (formal charge)• Neutral (e.g. :CO, :PR3, :NH3)• Anionic (e.g. Cl-, O2-, CH3
-)• Cationic (rare!) (e.g. NO+, C7H7
+)
(B) Hard/Soft propertiesHard : period 1 donor (NH3, OH2)Soft : carbon (CO, CH3
-, CH2=CH2) & period 2 donors (PR3, SR2)
15
(C) No. of donor atom
NH3 NH2CH2CH2NH2 NH(CH2NH2)2
unidentate bidentate tridentate
ammoniaor ammine
ethylenediamine(en)
diethylenetriamine(dien)
N N N N N N
pyridinepy
2,2'-bipyridinebipy
2,2':6',6"-terpyridineterpy
Metal complexes with polydentate (chelating) ligands are more stable than those with unidentate analogues.
Chelate effect
16
17
18
(ii) acceptors ( acids)
19
Exercises
Classify the following ligands as donor, acceptor, or ligands
• NMe3
• I-
• NO+
• CN-
• OH-
• H-
• CH3-
20
Nomenclature
(1) Ligands in alphabetical order(3) Indicate O.N. of metal (in Roman no.: I, II, 0)(4) Indicate the no. of L and M (di, tri, tetra etc.).
Also bis, tris, tetrakis(5) Anionic ligand o;
e.g. Cl- (chloro), H- (hydrido), CN- (cyano) (6) Anionic complexes => atee.g. Mn (manganate), Fe (ferrate), Cr (chromate) etc
21
ML
LL
ML
L
LM
L
L
ML
L
trans cis fac mer
(7) Add structural prefixes, e.g. cis/ trans, fac/ mer etc.
Examples: K3[Mn(CN)6] Tripotassium hexacyanomanganate(III)Na2[Fe(CO)4]Disodium tetracarbonylferrate(-II)
22
ExercisesName the following compounds (1) [Mn2(CO)10], [Co2(CO)8]
(2) [Ru(PPh3)4Cl2]
(3) K2[Pt(CN)4]
(4) [Cr(NH3)3(H2O)(OH)Cl][NO3]