Solid State Conformational Preferences of a Flexible
Molecular Backbone Derived from Acetone. Dependence
on Electron Donating/Withdrawing Ability of Substitutions
Sunil Varughese and Sylvia M. Draper
Supporting Information
Index
No. Contents Page
1 ORTEP of 1,3bis(phenyl)acetones S1 2 Hydrogen bond table S3 3 Experimental section S4 4 Infra-red spectra S7 5 SEM Images S9
S1
ORTEP of bis(phenyl)acetones
1,3-Bis(phenyl)acetone, 1
1,3-Bis(4-methylphenyl)acetone, 2
1,3-Bis(4-tert-butylphenyl)acetone, 3
S2
1,3-Bis(4-methoxyphenyl)acetone, 4
1,3-Bis(4-bromophenyl)acetone, 5
1,3-Bis(4-methoxycarbonylphenyl)acetone, 6
S3
1,3-Bis(4-nitrophenyl)acetone, 7
Hydrogen bond table
C–H...O 1 2.48 3.25 135
2.71 3.61 159 2.99 3.90 154
2 2.51 3.45 173
3 2.75 3.66 168 2.77 3.69 168 2.80 3.74 171 2.82 3.74 171
4 2.53 3.47 168 2.64 3.47 143
5 2.58 3.55 172 2.69 3.50 141 2.73 3.44 130 2.77 3.43 128 2.86 3.46 123 2.95 3.86 163
6 2.47 3.32 143
S4
2.74 3.44 133 2.75 3.47 132
7 2.38 3.25 147 2.47 3.41 174 2.47 3.21 131 2.55 3.39 145 2.55 3.25 127 2.60 3.45 149 2.62 3.34 130 2.85 3.48 125 2.86 3.59 134 2.88 3.69 144 2.89 3.85 166 2.90 3.82 164 2.92 3.80 149 2.97 3.77 142
Experimental section
The chemicals were purchased from Aldrich and used without further purification.
Reagent grade solvent was used for the reaction. 1,3-Bis(phenyl)acetone, 1, was obtained
from Aldrich and was used for crystallization. The substituted bis(phenyl)acetones were
prepared as per the procedure available in the literature.
General preparation method for 2, 3, 5 and 6.
An aqueous solution (100 cm3) of calcium hydroxide (2 mol) and tetra-n-
butylammoniumhydrogensulfate (phase-transfer catalyst) (0.25 mol) was prepared and
introduced into a 500 cm3, three-necked flask kept at room temperature. Measured quantities
of respective benzylbromide (1 mol) and dichloromethane (100 cm3) were then added to the
reactor. The solution was agitated at 700 rpm for 15 min and the reactor was purged with
inert nitrogen gas. A known quantity of iron pentacarbonyl (0.5 mol) was then added to the
reactor. The purging was continued for a further 30 min and the flask was tightly closed and
was left for stirring overnight. The resulting reaction mixture was further supplied with 100
cm3 dichloromethane and was purged with air for 15 min to quench the reaction. Further, a
10% HCl solution (25 cm3) was added and was continuously purged with air with vigorous
stirring. The resulting reaction mixture was extracted with dichloromethane and the volume
was reduced under vacuum. The resulting material was purified using column
chromatography on silica.1
S5
In the case of the methyl derivative 2, instead of dichloromethane, benzene was used
as the reaction solvent.2
Methyl derivative, 2:
Column chromatography on silica using hexane:ethylacetate (9:1) as eluent.
1HNMR (CDCl3, δ/ppm): 7.18 (d, 4H, Ar), 7.10 (d, 4H, Ar), 3.72 (s, 4H, –CH2–),
2.39 (s, 6H, –CH3). Melting point: 52 oC.
t-Butyl derivative, 3:
Column chromatography on silica using dichloromethane:hexane (1:1) as eluent. 1HNMR (CDCl3, δ/ppm): 7.35 (d, 4H, Ar), 7.21 (d, 4H, Ar), 3.61 (s, 4H, –CH2–),
1.32 (s, 18H, –C(CH3)3).
Bromo derivative, 5:
Column chromatography on silica using dichloromethane:hexane (6:4) as eluent. 1HNMR (CDCl3, δ/ppm): 7.47 (d, 4H, Ar), 7.03 (d, 4H, Ar), 3.71 (s, 4H, –CH2–).
Melting point: 117 oC.
Ester derivative, 6:
Column chromatography on silica using hexane:ethylacetate (8:2) as eluent. 1HNMR (CDCl3, δ/ppm): 7.19 (d, 4H, Ar), 7.06 (d, 4H, Ar), 3.81 (s, 4H, –CH2–),
2.38 (s, 6H, –OCH3). Melting point: 140 oC.
General preparation method for 4 and 7.
A solution of substituted phenylacetic acid (1 mol) in dry dichloromethane was added
slowly to a solution of DCC (1 mol) and DMAP (0.25 mol) in dry dichloromethane in an
inert atmosphere. The reaction mixture was kept for 24 hrs stirring at room temperature and
then filtered. The filtrate was distilled off and the residue was purified by column
chromatography over silica gel.3
Methoxy derivative, 4:
Column chromatography on silica using ethylacetate:hexane (3:7) as eluent. 1HNMR (CDCl3, δ/ppm): 7.08 (d, 4H, Ar), 6.88 (d, 4H, Ar), 3.82 (s, 6H, –OCH3),
3.61 (s, 4H, –CH2–). Melting point: 85.5 oC.
Nitro derivative, 7:
S6
Column chromatography on silica using dichloromethane as eluent. 1HNMR (CDCl3, δ/ppm): 8.22 (d, 4H, Ar), 7.36 (d, 4H, Ar), 3.96 (s, 4H, –CH2–).
Melting point: 178-179 oC.
X-ray analysis: Single crystals of 1-7 were carefully chosen after they were viewed through
a microscope supported by a rotatable polarizing stage. The crystals were glued to a thin glass
fibre using NIH immersion oil and mounted on a diffractometer equipped with an APEX
CCD area detector. All the data were collected at 123K. The intensity data were processed
using Bruker’s suite of data processing programs (SAINT), and absorption corrections were
applied using SADABS.4 The structure solution of all the complexes was carried out by
direct methods, and refinements were performed by full-matrix least-squares on F2 using the
SHELXTL-PLUS suite of programs.4 All the non-hydrogen atoms were refined
anisotropically, and the hydrogen atoms were fixed on the calculated positions using
appropriate AFIX commands and were refined isotropically. Intermolecular interactions were
computed using the PLATON program. 5
Nanoparticle preparation and analysis: The nanoparticles were prepared by the rapid
injection of 50 μL 10-3 M compound in dimethylformamide (DMF) (filtered through a
nanoporous alumina membrane (Whatman, Anodisc 13)) to 20 mL Millipore water under
ultrasonication. The solution was kept at isothermal condition (45 oC) for 24 hours and was
filtered through anodisc (20nm). The morphology of the nanoparticles was analyzed using a
TESCAN scanning electron microscope using a beam voltage of 5kV.
References:
(1) Draper, S. M.; Gregg, D. J.; Madathil, R. J. Am. Chem. Soc. 2002, 124, 3486-3487.
(2) Wu, H. –S.; Tan, W. –H.; J. Chem. Tech. Biotechnol. 1996, 67, 381-387.
(3) Sumita, B.; Suprabhat, R. Synth. Commun. 1998, 28, 765-771.
(4) a) Siemens, SMART System, Siemens Analytical X-ray Instruments Inc., Madison,
WI, USA, 1995; b) Sheldrick, G. M. SADABS Siemens Area Detector Absorption
Correction Program, University of Gottingen, Gottingen, Germany, 1994; c)
Sheldrick, G. M. SHELXTL-PLUS Program for Crystal Structure Solution and
Refinement, University of Gottingen, Gottingen, Germany.
(5) Spek, A. L. PLATON, Molecular Geometry Program, University of Utrecht, The
Netherlands, 1995.
S7
IR Spectra of 1,3-bis(phenyl)acetones,1-4
1000 1500 2000 2500 3000 3500
t-butyl
-CH3
-H
Acetone
Tra
ns
mit
tan
ce
Wave number
-OMe
S8
IR Spectra of 1,3-bis(phenyl)acetones,1 & 5-7
1000 1500 2000 2500 3000 3500
Ester
-Br
-H
Acetone
Tra
nsm
itta
nc
e
Wavenumber
Nitro
S9
Additional SEM images
Methyl derivative (2)
S10
t-Butyl derivative (3)
S11
Methoxy derivative (4)
S12
Bromo derivative (5)
S13
Ester derivative (6)
S14
Nitro derivative (7)
