Structural elucidation, density functional calculations and contribution of intermolecular interactions in cholest-4-en-3-one crystals: Insights from X-ray and Hirshfeld surface analysis

Article abstract of DOI:10.1016/j.molstruc.2014.12.027

The foremost objective of the present work is systematic analysis of intermolecular interactions in crystal structure of cholest-4-en-3-one (2) molecule. It is accomplished by Hirshfeld surface analysis and fingerprint plot. Hirshfeld surface analysis has been used to visualize the fidelity of the crystal structure. This method permitted for the identification of individual types of intermolecular contacts and their impact on the complete packing. Molecules are linked by a combination of CO - -H, CH - -H, and C - -H contacts, which have clear signatures in the fingerprint plots. The theoretical study was attempted to predict the optimized geometry and computed spectra by the Density Functional Theory (DFT) using the B3LYP function with the 6-311++G(d,p) basis set. Atomic charges, MEP mapping, HOMO-LUMO, various thermodynamic and molecular properties have been reported. In addition thermal stability, optical, morphological, and microstructral properties of the title compound (2) have also been explored.

Full text of DOI:10.1016/j.molstruc.2014.12.027

Journal of Molecular Structure 1084 (2015) 274–283
Contents lists available at ScienceDirect
Journal of Molecular Structure
journal homepage: www.elsevier.com/locate/molstruc
Structural elucidation, density functional calculations and contribution
of intermolecular interactions in cholest-4-en-3-one crystals: Insights
from X-ray and Hirshfeld surface analysis
a
a
b
c
d
Hena Khanam , Ashraf Mashrai , Nazish Siddiqui , Musheer Ahmad , Mohammad Jane Alam ,
d
a,
⇑
Shabbir Ahmad , Shamsuzzaman
a
Steroid Research Laboratory, Department of Chemistry, Aligarh Muslim University, Aligarh 202002, UP, India
Department of Ilmuladvia, Aligarh Muslim University, Aligarh 202002, India
Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
Department of Physics, Aligarh Muslim University, Aligarh 202002, India
b
c
d
h i g h l i g h t s
g r a p h i c a l a b s t r a c t
In the present work we have described synthesis and single crystal X-ray analysis of cholest-4-en-3-one.
Intermolecular interactions have been studied through Hirshfeld surface analysis/finger print plot. In
addition density functional calculations have also been performed.
ꢀ
ꢀ
ꢀ
ꢀ
Synthesis and single crystal structure
of cholest-4-en-3-one has been
performed.
Hirshfeld surface analysis has been
used for the identification of
intermolecular contacts.
The theoretical study was attempted
to predict the optimized geometry by
DFT.
Optical, morphological, and
microstructral properties has also
been explored.
a r t i c l e i n f o
a b s t r a c t
Article history:
The foremost objective of the present work is systematic analysis of intermolecular interactions in crystal
structure of cholest-4-en-3-one (2) molecule. It is accomplished by Hirshfeld surface analysis and finger-
print plot. Hirshfeld surface analysis has been used to visualize the fidelity of the crystal structure. This
method permitted for the identification of individual types of intermolecular contacts and their impact
on the complete packing. Molecules are linked by a combination of C@O—H, CAH—H, and C—H contacts,
which have clear signatures in the fingerprint plots. The theoretical study was attempted to predict the
optimized geometry and computed spectra by the Density Functional Theory (DFT) using the B3LYP func-
tion with the 6–311++G(d,p) basis set. Atomic charges, MEP mapping, HOMO–LUMO, various thermody-
namic and molecular properties have been reported. In addition thermal stability, optical, morphological,
and microstructral properties of the title compound (2) have also been explored.
Received 3 September 2014
Received in revised form 5 December 2014
Accepted 8 December 2014
Available online 19 December 2014
Keywords:
Steroids
Cholest-4-en-3-one
X-ray
Hirshfeld
DFT
Ó 2014 Elsevier B.V. All rights reserved.
⇑
Corresponding author. Tel.: +91 9411003465.
E-mail address: shamsuzzaman9@gmail.com (Shamsuzzaman).
http://dx.doi.org/10.1016/j.molstruc.2014.12.027
022-2860/Ó 2014 Elsevier B.V. All rights reserved.
0

H. Khanam et al. / Journal of Molecular Structure 1084 (2015) 274–283
275
Introduction
diffraction (Cu Ka radiation, scan rate 3°/min, 293 K, k = 1.54 Å)
was performed on a Bruker D8 Advance Series 2 powder X-ray dif-
fractometer. UV–visible spectrum was recorded on UV–vis spectro-
photometer (Perkin Elmer Life and Analytical Sciences, CT, USA) in
the wavelength range of A 200–700 nm. The fluorescence spectrum
was collected at 37 °C with a 1 cm path length cell using a Hitachi
spectrofluorometer (Model 2500) equipped with a PC and the
emission slit were set at 5 nm. The emission spectrum was
recorded in the range of 300–800 nm. The surface morphology of
the compound was monitored using JEOL JSM-6510LV scanning
electron microscope (SEM), equipped with energy-dispersive X-
ray spectroscopy (EDX) analyzer.
The chemistry of steroids is of significant importance because of
the roles undertaken by these molecules in both animals and
plants [1]. An attractive feature of steroidal structures would be
their applications in crystal engineering, which would take advan-
tage of their tendency to occur in different crystal forms [2]. The
interesting structural and stereochemical features of the steroid
nucleus provide additional fascination to the researchers, and
thereby alterations in the steroidal skeleton have been envisaged
to discover new chemical entities with a potential to afford some
promising drugs of the future [3]. During the second half of the last
century, chemical studies on steroids, including cholesterol, were
intensively conducted. Cholesterol, as an allylic alcohol with a
large hydrophobic portion, undergoes various transformations
and can be applied in various chemical syntheses, such as steroid
hormones, ecdysteroids, vitamin D derivatives and brassinoster-
oids. Cholesterol is frequently used as a model system for testing
many constructive chemical and enzymatic reactions, which have
been now widely used for multi-step steroid transformations lead-
ing to products of practical importance. Cholest-4-en-3-one, a cho-
lesterol derivative, is an important synthetic intermediate in many
steroid transformations [4]. It has been shown to be implicated in
Synthesis of cholest-4-en-3-one
Synthesis of the title compound (2) (m.p. 80–81 °C) was per-
formed by reported method [12]. Recrystallization from methanol
afforded cholest-4-en-3-one crystals as colorless needles suitable
for X-ray diffraction (Scheme 1).
Anal. Calcd for C27
H
44O: C, 84.31; H, 11.53. Found: C, 84.48; H,
ꢁ1
11.38; IR (KBr, cm ): 2943, 2866 (CAH, stretching), 1673 (C@O),
1
1617 (C@C); H NMR (CDCl
C4AH), 1.18 (3H, s, 10-CH ) 0.71 (3H, s, 13-CH
methyl protons); C NMR (CDCl , 100 MHz): d ppm: 199.6, 171.7,
3
, 400 MHz): d ppm: 5.72 (1H, s,
3
3
), 0.92 & 0.85 (other
1
3
the metabolic pathways from cholesterol to 5
and 5b-cholestanol [5]. From the structural point of view, cholest-
-en-3-one crystals have a monoclinic structure with a space
group P2 with cell parameters a = 14.634 (5), b = 7.862 (5),
a-cholest-7-en-3b-ol
3
123.7, 56.1, 55.8, 53.8, 42.3, 39.6, 39.5, 38.6, 36.1, 35.7, 35.6, 35.6,
33.9, 32.9, 32.0, 28.1, 28.0, 24.1, 23.8, 22.8, 22.5, 21.0, 18.6, 17.3,
4
+
11.9. MS(EI): m/z 384.34 [M ].
1
c = 10.674 (5) Å, b = 105.1 (2)°, Z = 2 [6]. There has been observed
the growing interest in applications of Hirshfeld surface analysis
in the field of crystallography, as this approach is a very convenient
tool for the investigation of different kinds of intermolecular inter-
actions. Since crystal structure gives the most definite understand-
ing of the intermolecular contacts and crystal packing, Hirshfeld
surface [7–9] based tools appear to be particularly suitable for
the visualization of variations in the intermolecular interactions
of the compounds. The surfaces encode information about all inter-
molecular interactions offer a facile way for obtaining an idea on
crystal packing. The breakdown of the associated fingerprint plots
X-ray crystallographic study
Single crystal X-ray data of compound 2 was collected at 100 K
on a Bruker SMART APEX CCD diffractometer using graphite mono-
chromated Mo K radiation (k = 0.71073 Å). The linear absorption
a
coefficients, scattering factors for the atoms, and the anomalous
dispersion corrections were taken from the International Tables
for X-ray Crystallography [13]. The data integration and reduction
were carried out with SAINT [14] software. Empirical absorption
correction was applied to the collected reflections with SADABS
[15] and the space group was determined using XPREP [16]. The
structure was solved by the direct methods using SHELXTL-97
[
10] explores quantitatively the types of intermolecular contacts
experienced by molecules and presents this information in a con-
venient color plot. As part of our ongoing studies on synthesis
and single crystal X-ray analysis of steroids [11], the single crystal
analysis was undertaken along with the Hirshfeld surface analysis
to investigate the close contacts. Theoretical calculations were per-
formed by using B3LYP function with the 6–311++G(d,p) basis set.
Besides, spectral, thermal, optical and morphological properties
were also investigated.
2
[17] and refined on F by full-matrix least-squares using the SHEL-
XL-97 [18] program package. All non-hydrogen atoms were refined
anisotropically. Crystallographic data (excluding structure factors)
for the structures reported in this article have been deposited with
the Cambridge Crystallographic Data Centre (CCDC) as deposition
no. CCDC 99399. All H-atom positions were calculated geometri-
cally with Uiso (H) = 1.2–1.5 ÅA Ueq (parent atom). A riding model
was used in their refinement (CAH@0.98–1.00 Å).
0
Experimental
Hirshfeld surfaces calculations
General comments
Molecular Hirshfeld surfaces [7] in the crystal structure have
been constructed based on the electron distribution calculated as
the sum of spherical atom electron densities [19]. For a given crys-
tal structure and set of spherical atomic electron densities, the
Hirshfeld surface is unique [20], and it is this property that sug-
gests the possibility of gaining additional imminent into the inter-
molecular interaction of molecular crystals. The Hirshfeld surfaces
and fingerprint plots presented here were generated using Crystal-
Explorer [21] based on results of X-ray studies. During the calcula-
tions, bond lengths to hydrogen atoms were normalized to
standard neutron values (CAH@1.083 Å) [22] in order to ensure
the internal consistency and independence of results from the
crystal structure refinement method. The 2D fingerprint plots dis-
All reagents and solvents were commercially available and used
as received. Melting point was determined on digital auto melting
point apparatus. Elemental analysis of the compound was recorded
on Perkin Elmer 2400 CHN Elemental Analyzer. The IR spectrum
was recorded on KBr pellets with Spectrum Two by Perkin Elmer
Spectrometer and values are given in cm . H and C NMR spec-
tra were run in CDCl on a Bruker Avance II 400 NMR Spectrometer
at 400 MHz and 100 MHz respectively. Chemical shifts (d) are
ꢁ1
1
13
3
1
reported in ppm relative to the TMS ( H NMR, 400 MHz) and to
1
3
the solvent signal ( C NMR spectra, 100 MHz) and coupling con-
stants are given in Hz. Thermal study of the compound was carried
out using TGA/DTA- 60H instrument (SHIMADZU) at a heating rate
played by using the standard 0.6–2.6 Å view with the d
e i
and d dis-
ꢁ1
of 20 °C min from ambient temperature to 800 °C. Powder X-ray
tance scales displayed on the graph axes. The normalized contact

2
76
H. Khanam et al. / Journal of Molecular Structure 1084 (2015) 274–283
Br , AcOH, NaOAc, Et O
2
2
H
H
H
H
Zn, Et O
H
H
2
HO
HO
Br
Br
Cholest-5-en-3β-ol (1)
3β-Hydroxy-5α, 6β-dibromocholestane (A)
H
H
Jone's reagent
H
Zn
(
A)
H
acetone
H
H
O
Et2O, AcOH
Br
O
Br
5
α, 6β-Dibromocholestan-3-one (B)
Cholest-5-en-3-one (C)
H
(COOH)2
(
C)
H
H
O
Cholest-4-en-3-one (2)
Scheme 1. Synthesis of cholest-4-en-3-one.
distance (dnorm) based on both d
given by Eq. (1) enables identification of the regions of particular
importance to intermolecular interactions [7]. Because of the sym-
metry between d and d in the expression for dnorm, where two
e i
Hirshfeld surfaces touch, both will display a red spot identical in
color intensity as well as size and shape.
e
, d
i
and the vdw radii of the atom,
in head to tail manner and the crystal packing is stabilized by a com-
bination of intermolecular interactions (C@O—H, CAH—H, C—H)
(Figs. 1–3). Rings B and C exist in normal chair conformation. Ring
A adopts sofa conformation (because of the presence of double
bond), and ring D is intermediate between envelope & half-chair.
The A/B ring junction is quasi-trans, while the B/C and C/D ring sys-
tems are trans fused about the C(8)AC(9) and C(14)AC(15) bonds,
respectively. The bond distances and bond angles in compound 2
v
dw
vdw
d
i
ꢁ r
i
d
e
ꢁ r
vdw
i
e
d
norm
¼
þ
ð1Þ
v
dw
r
r
e
are found to be almost equivalent to reported earlier [6]. Ring bond
0
lengths have normal values with an average of 1.528 (3) ÅA , while th0e
cholestane side chain shows an average bond length of 1.521 (3) ÅA .
The bond length C(1)AO and C(6)AC(5) are 1.224 (3) and 1.340 (4) Å
respectively, which indicates a double-bond character [24]. Side-
chain is fully extended with a gauche-trans conformation of the ter-
minal C27 and C28 methyl groups. The absolute configurations of
chiral centers were determined from the structure presented, these
sites exhibit the following chiralities: C4 = R, C8 = S, C9 = S, C14 = R,
C15 = S, C17 = R and C20 = R. Since there is no strong hydrogen bond
donor in the molecule, cohesion of the crystal structure can only be
attributed to van der Waals interactions. Pertinent crystallographic
data and refinement details for the structural analyses of the com-
pound 2 are summarized in Tables 1 and 2. It is important to note
that earlier report [6] did not provide any information regarding
the presence of intermolecular contacts, but we have explored
and studied deeply the presence of short intermolecular contacts
and this has been well analyzed by Molecular Hirshfeld surfaces.
Theoretical calculations
The entire theoretical calculations were performed at Density
Functional Theory using Gaussian 03W [23] The molecular geom-
etry and vibrational spectra of the present molecule have been
computed using DFT (B3LYP) method with 6–311++G(d,p) basis
set.
Results and discussion
IR, H NMR, 13C NMR, elemental analysis and single crystal XRD
data are compatible with the putative structure depicted in
Scheme 1.
1
Description of crystal structure
The title compound (2) crystallizes in the monoclinic system,
Molecular Hirshfeld surfaces
1
space group P2 which can be explained by the presence of 7 chiral
centers [22]. There is only one molecule in the asymmetric unit,
while unit cell contains 2 molecules. The molecules are arranged
Hirshfeld surface is a useful tool for describing the surface char-
acteristics of the molecules. It represents the area where molecules

H. Khanam et al. / Journal of Molecular Structure 1084 (2015) 274–283
277
Fig. 1. ORTEP view of cholest-4-en-3-one, ellipsoids are drawn at 50% probability level.
Fig. 2. 2D-view of cholest-4-en-3-one.
O....H
C....H
H....H
C
H
O
Fig. 3. Short intermolecular contacts present within the cholest-4-en-3-one molecules.
come into contact, therefore, its analysis gives the possibility of
obtaining additional insight into the intermolecular interactions
in the crystal state. The Hirshfeld surface enclosing a molecule is
defined by points where the contribution to the electron density
from the molecule of interest is equal to the contribution from
all the other molecules. For each point on that isosurface two dis-
range of ꢁ4.0 to 0.4. The molecular Hirshfeld surface (dnorm, shape
index and curvedness) of cholest-4-en-3-one are shown in Fig. 4a–
c. For comparison of intermolecular interactions scheme in crystal
structures, the normalized contact distances, dnorm, based on van
der Waals radii, were mapped into the Hirshfeld surfaces. In the
color scale, negative values of dnorm are visualized by the red color,
indicating contacts shorter than the sum of van der Waals radii.
The white color denotes intermolecular distances close to van
der Waals contacts with dnorm equal to zero. In turn, contacts longer
than the sum of van der Waals radii with positive dnorm values are
indicated by blue. The O—H and C—H interaction in compound 2
can be seen in the Hirshfeld surface as the bright red areas. The
other visible spots on the surface correspond to H—H contacts
tances are defined: d
nucleus external to the surface), and d
e
(the distance from the point to the nearest
(the distance to the nearest
i
nucleus internal to the surface). The molecular Hirshfeld surfaces
of cholest-4-en-3-one were generated using a standard (high) sur-
face resolution with the 3D dnorm surfaces were mapped over a
fixed color scale of ꢁ0.23 (red) to 1.2 Å (blue), the shape index
mapped in the color range of ꢁ0.99 to 1 and curvedness in the

2
78
H. Khanam et al. / Journal of Molecular Structure 1084 (2015) 274–283
Table 1
Crystal data and structure refinement for cholest-4-en-3-one.
Empirical formula
Formula mass
Wavelength (k)
Crystal system
Space group
27 44
C H O
384.62
0.71073 Å
Monoclinic
P2
1
Unit cell dimensions
0
1
7
1
0.543(5)
.786(5)
a, ÅA
0
b, ÅA
0
4.506(5)
c, ÅA
a
(°)
b (°)
(°)
90.000
105.919(5)
90.000
c
0
Volume, ÅA 3
1145.1(10)
No. of molecules per unit cell (Z)
2
ꢁ
3
Calculated density, Mg m
1.116
0.065
428
Absorption coefficient (
F(000)
l
, mmꢁ1)
Crystal size
0.21 ꢂ 0.14 ꢂ 0.10 mm
h range for data collection
Limiting indices
1.46–25.50°
ꢁ11 6 h 6 12, ꢁ9 6 k 6 9, ꢁ15 6 l 6 17
1.067
Goodness-of-fit on F2
Final R indices [I > 2
R indices (all data)
r(I)]
R1 = 0.0525, wR2 = 0.1194
R1 = 0.0674, wR2 = 0.1384
1 o c o o o 2 o c o
R = R||F | – |F ||/R|F > 2r(F = [Rw(|F |) /R|F
| with F 2 2). wR 2|–|F | ]1/2.
2
2
2 2
(Fig. 4a). Shape index (Fig. 4b) is a measure of ‘‘which shape’’, and it
can be sensitive to very subtle changes in surface shape, particu-
larly in areas where the total curvature (or the curvedness) is very
low. The information conveyed by shape index is consisted with
the 2D fingerprint plot. The curvedness (Fig. 4c) is the measure-
ment of ‘‘how much shape’’; the flat areas of the surface corre-
spond to low values of curvedness, while sharp curvature areas
correspond to high values of curvedness and usually tend to divide
the surface into patches, indicating interactions between neighbor-
ing molecules. The 2D fingerprint plots can be decomposed to
highlight particular atom pair close contacts [19]. This decomposi-
tion enables separation of contributions from different interaction
types, which overlap in the full fingerprint. The 2D fingerprint
plots, which analyses all of the intermolecular contacts at the same
time, revealed that the main intermolecular interactions in com-
pound were C—H, CAH—H, and C@O—H intermolecular interac-
tions (Fig. 5a). C@H—H interactions, which were reflected in the
middle of scattered points and cover most area in the 2D finger-
print plots, have a most significant contribution to the total Hirsh-
feld surfaces (88.5%) (Fig. 5b). The O—H/H—O contacts appear as
distinct spikes pointing toward the lower left of the plot (Fig. 5c).
Complementary regions are visible in the fingerprint plots where
Fig. 4. Hirshfeld surfaces mapped with (a) dnorm, (b) surface index and (c) curvedness
of cholest-4-en-3-one. The surfaces are shown as transparent to allow visualization
of the orientation and conformation of the functional groups in the molecules.
‘
(
‘wings’’ which are identified as a result of C—H interactions
Fig. 5d). The decomposition of the fingerprint plot shows that
C—H/H—C contacts comprise 2.8% of the total Hirshfeld surface
area. Fig. 6 contains the percentages of contributions for a variety
of contacts in the title crystal structure. Thus the nature of the
interplay of the title compound is more easily understood using
Hirshfeld surface, with the results further highlighting the power
of the technique in mapping out the interactions within the crystal
and this methodology has very important promise in crystal engi-
neering. Undoubtedly, the Hirshfeld surface allows a much more
detailed scrutiny by displaying all the intermolecular interactions
and by quantifying them in 2D fingerprint plot within the crystal.
In fact it is a novel tool in crystal structure prediction.
one molecule act as donor (d
e
> d
i
) and the other as an acceptor
+ d
(d
e
< d ). The shortest contact i.e., the minimum value of (d
i
e
i
)
Theoretical study
is around 1.9 Å point out the importance of these interactions.
The proportion of O—H/H—O interactions comprising 8.8% of the
total Hirshfeld surfaces for each molecule of (2). At the top left
and bottom right of the fingerprint plot, there are characteristic
Frontier molecular orbitals
The frontier orbitals, HOMO and LUMO are imperative parame-
ters for determining the way the molecules interacts with other
Table 2
Optimized structural parameters (selected bond lengths and bond angles) of cholest-4-en-3-one at B3LYP/6–311++G(d,p) level of theory.
Bond lengths (Å)
Bond angles (°)
Experimentala
Calculated (B3LYP/6–311G(d,p))
Experimentala
Calculated (B3LYP/6–311G(d,p))
C1AO1
C2AC1
C1AC6
C6AC5
C5AC11
1.224(3)
1.491(4)
1.466(4)
1.340(4)
1.496(4)
1.223
1.519
1.472
1.349
1.509
C2C1O1
C6C1O1
C1C6C5
H6C6C5
C4C5C11
121.6(3)
121.7(3)
123.8(3)
121(2)
122.38
121.90
124.38
120.43
116.87
116.7(2)
a
Obtained from single crystal XRD data.

H. Khanam et al. / Journal of Molecular Structure 1084 (2015) 274–283
279
Fig. 5. 2D fingerprint plots of cholest-4-en-3-one: (a) full (b) resolved into H—H and (c) O—H (d) C—H contacts showing the percentages of contacts contributed to the total
Hirshfeld surface area of molecule.
HOMO energy = ꢁ6.2 eV.
LUMO energy = ꢁ1.13 eV.
HOMO–LUMO energy gap = ꢁ5.07 eV.
C--H/H--C
O--H/H--O
H--H
The lowering of HOMO–LUMO energy gap supports bioactive
property of the molecule. Gauss-Sum 2.2 program [25] was used
to create the density of states spectrum (DOS) by convoluting the
molecular orbital information with Gaussian curves of unit height
(
Fig. S1). The green and blue lines in the DOS spectrum indicated
the HOMO and LUMO levels.
Fig. 6. Relative contribution of various intermolecular interactions to the Hirshfeld
surface area.
Molecular electrostatic potential map
The molecular electrostatic potential (MEP) maps have been
used to predict the behavior and reactivity of the molecules. It is
mapping potentials created in the space around a molecule by its
nuclei and electrons. MEP map is very constructive for the qualita-
tive interpretation of the electrophilic and nucleophilic reactions
for the study of biological recognition process and hydrogen bond-
ing interactions [26]. This also provides information for under-
standing the shape, size, charge density, delocalization and site of
chemical reactivity of the molecules. There are three important
colors; blue, red and green used to indicate the value of the electro-
static potential. The surfaces with blue and red colors show the
positive and negative values of the potential respectively. The sur-
faces with green colors indicate zero potential. MEP map for the
species (Fig. 7). HOMO, the outermost orbital containing electrons
has tendency to release electrons as an electron donor. On the
other hand; LUMO orbital has free space to accept electrons as
electron acceptor. The ability of charge transfer interactions within
molecule can be explained by the HOMO–LUMO energy gap. The
positive and negative phases are represented by red and green
color, respectively. The energy values correspond to HOMO and
LUMO and their energy gap show the chemical activity and kinetic
stability of the molecule. The HOMO–LUMO energy and the gap
between them, at B3LYP/6–311++G(d,p), are given as follows:

2
80
H. Khanam et al. / Journal of Molecular Structure 1084 (2015) 274–283
Fig. 7. Cholest-4-en-3-one (a) HOMO (b) LUMO.
Fig. 8. MEP map for cholest-4-en-3-one.
Fig. 9. The optimized molecular structure of cholest-4-en-3-one.
cholest-4-en-3-one at B3LYP/6–311G(d,p) level of theory is shown
Molecular geometry
1
ꢁ2
in Fig. 8 with color range from ꢁ6.068e
(deepest red) to
(deepest blue). The red color surfaces with negative
The optimized molecular structure of cholest-4-en-3-one along
with numbering of atoms is shown in Fig. 9. For the optimized geom-
etry, the minimum energy value was found as ꢁ1130.6821 a.u. In
the present work, the calculated optimized geometrical parameters
are found in a reasonable agreement with the X-ray diffraction data
(Table 2).
ꢁ2
+
6.068e
MEP belong to high electron density, indicating a strong attraction
between the proton and points on the molecular surface. The blue
color surfaces correspond to areas of lowest electron density
(
Table S1).
Vibrational analysis
Cholest-4-en-3-one is a chiral molecule and belongs to C1 point
group. The theoretical wave numbers corresponding to these bands
1
For interpretation of color in Fig. 8, the reader is referred to the web version of
this article.

H. Khanam et al. / Journal of Molecular Structure 1084 (2015) 274–283
281
Table 3
Theoretical computed zero point vibrational energy (kcal mol ), rotational constants
process. Computational methods are valuable and sometimes
indispensable tool in obtaining the thermodynamic quantities of
molecules. These data not only reflect the extent of intermolecular
interactions but they also dictate the character of interaction of
biomolecules. Several thermodynamic parameters have been com-
puted at B3LYP method utilizing 6–311++G(d,p) basis set. These
are tabulated in Table 3. Calculated electric dipole moments, polar-
izabilities anisotropy, and hyperpolarizibility value of cholest-4-
en-3-one molecule are given in Supplementary Tables S2–S4.
ꢁ
1
ꢁ
1
(
GHz), rotational temperature (K), thermal energy (kcal mol ), molar capacity at
ꢁ
1
ꢁ1
constant volume and entropy (cal mol
K
) at STP.
Parameters
B3LYP/6–311++G(d,p)
415.78342
Zero point vibrational energy
Rotational constants
0.58816
0
0
.05315
.05158
Rotational temperatures
0.02823
0
0
.00255
.00248
Morphology
Energy total
Translational
Rotational
433.967
0.889
0.889
It is useful to know the relation between morphological varia-
tions and the growth parameters which extends to applied fields
including pharmaceuticals, quality control of optoelectronic crys-
tals and industrial crystallization. The morphology of cholest-4-
en-3-one crystal was predicted using WinXMorph program
Vibrational
432.189
Molar capacity at constant volume
Total
Translational
Rotational
116.246
2.981
2.981
110.285
187.497
43.731
36.542
107.223
[
30,31] and it is depicted in Fig. 10. The morphology of cholest-
4-en-3-one revealed the well developed four facets such as
ꢀ ꢀ ꢀ ꢀ
Vibrational
Entropy total
Translational
Rotational
(
123), (010), ð011Þ, ð111Þ. The morphology of the grown crystal
ꢀ ꢀ
shows that, ð011Þ facet has larger surface area than other facets.
ꢀ ꢀ ꢀ ꢀ
ꢀ
ꢀ
The angle between the facets (123) – ð111Þ, ð111Þ – ð011Þ and
Vibrational
ꢀ
ꢀ
ð011Þ – (010) of grown crystal found from morphology are
20.97°, 56.95° and 150.83° respectively.
1
were found to be in good agreement with the experimental values
Fig. S2).
FT-IR spectral analysis
(
Infrared spectroscopy is used to identify the functional groups
and modes of vibration of the synthesized compound. A sharp
strong band, characteristic of alpha, beta unsaturated carbonyl
Other molecular properties
The dipole moment and polarizability tensor are important
molecular properties for providing information about a distribu-
tion of charge within a molecule. The isotropic polarizability is a
measure of electronic distribution in a molecule, caused by an
external electric field. The permanent electric dipole moment of
a molecule is an important indicator of its behavior in physical,
chemical and biological process [27]. It is measure of the charge
density in a molecule and is a reactivity index which is important
to define biological properties related to the interaction with active
site of an enzyme [28]. The magnitude and direction of dipole
moment are sensitive to molecular size and shape and they serve
as tool in conformational analysis [29]. Knowledge on thermody-
namic properties is a key in understanding the rate and selectivity
of chemical process including design of viable industrial chemical
ꢁ
1
group (C@O) was found at 1674 cm . The characteristic bands in
ꢁ1
the range of 2869–2945 cm were ascribed to CAH stretching
ꢁ1
vibrations while the band at 1613 cm can be assigned to C@C
vibrations (Fig. S2a).
NMR analysis
NMR spectroscopy plays a vital role in the structural confirma-
1
tion of the grown material. H NMR spectrum (Fig. S3) of title com-
pound showed a singlet at d 5.72, attributed to olefinic proton.
Angular and side-chain methyl protons were observed at 1.18
(C10ACH ), 0.71 (C13ACH ), 0.92 and 0.85 for other methyl
3 3
Fig. 10. Equilibrium morphology of cholest-4-en-3-one single crystal.

2
82
H. Khanam et al. / Journal of Molecular Structure 1084 (2015) 274–283
⁄
an allowed
p
?
p
transition of C@CAC@O system. Fig. S7 shows
fluorescence image of the compound which indicated two broad
peaks around 350 and 450 nm with different intensities.
Density measurement
The calculated density of C27
the cell mass to cell volume; the equation used to calculate the
density is calc = MZ/NV, where M is the chemical formula weight
of C27 44O, Z is the number of formula units in one cell, N is Avo-
gadro’s number and V is the volume of the unit cell. According to
the crystallographic data, it is observed that a = 10.543(5) Å,
H44O was obtained by the ratio of
q
Fig. 11. Powder XRD plots: simulated from CIF and as-synthesised cholest-4-en-3-
one.
H
b = 7.786(5) Å,
V = 1145.1(10) Å . So the calculated density of the C27
was found to be 1.116 Mg m . The experimental density of the
cholest-4-en-3-one crystal was measured using the buoyancy
method at room temperature (22 °C) in silicon oil. The experimen-
c = 14.506(5) Å,
M = 384.62,
Z = 2,
and
protons. The characteristic signals in 13C NMR spectrum (Fig. S4)
were obtained at d 199.6 (C@O), 171.7 (C5) and 123.7 (C4).
Remaining carbon atoms were seen in accordance to the choles-
tane series.
3
H44O crystal
ꢁ3
tal density of the as-grown C27H44O crystal at 22 °C was found to
be 1.118 ± 0.002 Mg m , which is almost equal to the calculated
ꢁ3
Phase identification X-ray powder diffraction (PXRD)
density.
The powder form of the grown crystal (2) was subjected to
powder X-ray diffraction analysis. The appearance of sharp and
strong peaks suggested the good crystallinity of the title com-
pound. The diffractograms of compound are depicted in Fig. 11
which show lower and upper limit of (2h) between 5.00° and
Microstructural studies (SEM/EDX)
The crystal surface/morphology of cholest-4-en-3-one was
investigated by SEM. A scanning electron microscope (SEM) pro-
duces images of a sample by scanning it with a focused beam of
electrons. The electrons interact with electrons in the sample, pro-
ducing various signals that can be detected and that contain infor-
mation about the sample’s surface topography and composition.
The signals derived from electron sample interactions reveal infor-
mation about the sample including external morphology (texture),
the chemical composition, and the crystalline structure and orien-
tation of materials making up the sample. The SEM image (Fig. S8)
indicated presence of elongated, brick-shaped and some irregular
shaped particles with few microcrystals on it. EDX analysis showed
presence of C and O (Fig. S9).
4
0.00°. The XRD profile shows that the compound was of single
phase without detectable impurity. The lattice parameters of com-
pound were calculated using the powder XRD data and were found
in good agreement with the values obtained from single crystals.
Thermal analysis (TG/DTA)
Thermogravimetric/differential thermal analysis (TG/DTA)
measurements were performed under nitrogen atmosphere to
examine the thermal stabilities of the crystalline sample (com-
pound 2) and to define the conditions for the thermal treatment
on it. The thermograms observed from simultaneous TG/DTA are
illustrated in Fig. S5. The TG curve of compound revealed that it
is stable up to 240 °C (no weight loss) and does not undergo any
phase transition. The TG plot showed two resolved and well-
defined decomposition steps. The first decomposition step was
found in the temperature range of 240–420 °C with a net weight
loss of 92.551% (4.982 mg). The second decomposition step
occurred with a temperature range 420–520 °C with a net weight
loss of 6.762% (0.364 mg). The disintegration process continued
with the confiscation of almost all fragments as gaseous products,
leading to the bulk decomposition of the compound before 600 °C
since the initial mass of the sample was 5.383 mg and at a temper-
ature of about 600 °C, all the mass was lost and nothing was left as
residue. The absence of any weight loss or phase transition around
or before its melting point, confirmed the nonexistence of any lat-
tice entrapped solvent or moisture on the grown material. The cor-
responding DTA curve showed two notable thermal events. The
endothermic peaks were obtained at 89 and 354 °C. The sharp
endotherm was indicative of a solid-state transition for relatively
pure material.
Conclusion
In the present study, we have demonstrated synthesis of cho-
lest-4-en-3-one from cholesterol. Its crystal structure was solved
by using single crystal X-ray diffraction data. The crystal phase
and purity of the compound was established by X-ray powder dif-
fraction (XRD). Moreover spectral, thermal, optical and morpholog-
ical properties have also been investigated. The study of the title
compound underlines the way in which Hirshfeld surface and fin-
gerprint plot analysis provides rapid insight into the intermolecu-
lar interactions, which are crucial in crystal packing. Density
Functional Theory (DFT) using the B3LYP function with the 6–
3
11++G(d,p) basis set was applied to the solid state molecular
geometry obtained from single crystal X-ray studies. The opti-
mized molecular geometry and computed vibrational spectra were
compared with experimental results which showed appreciable
agreement. Finally, our study emphasizes the utility of Hirshfeld
surfaces and in particular, fingerprint-plot analysis for the ‘‘visual
screening’’ and detection of crystal structure features through a
Optical properties (absorption spectra/fluorescence spectra)
‘
‘whole structure’’ view of intermolecular contacts.
UV–visible spectroscopy is one of the best techniques to check
the suitability of the grown crystals for optical device fabrications.
The UV–visible absorption properties of cholest-4-en-3-one were
recorded in dichloromethane solution with the concentration of
Acknowledgments
The authors sincerely thank the chairman, department of chem-
istry Aligarh Muslim University, Aligarh for providing necessary
research facilities.
ꢁ
5
1
0
M. The absorption spectrum (Fig. S6) exhibited a strong, fea-
tureless absorption band around 260 nm, which can be assigned to

H. Khanam et al. / Journal of Molecular Structure 1084 (2015) 274–283
283
(
1
b) Shamsuzzaman, A. Mashrai, H. Khanam, Y.N. Mabkhot, W. Frey, J. Mole. Str.
063 (2014) 219–225.
Appendix A. Supplementary material
[
12] (a) L.F. Fieser, J. Am. Chem. Soc. 75 (1953) 5421–5422;
(b) L. Ruzicka, W. Bosshard, W.H. Fischer, H. Wirz, Helv. Chim. Acta 19 (1936)
1147–1153.
13] C.H. MacGillavry, G.D. Rieck, International Tables for X-Ray Crystallography,
vol. III, Kynoch Press, Birmingham, London, 1962.
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.molstruc.2014.12.
[
[
0
27.
14] SAINT, Version 6.02; Bruker AXS, Madison, WI, 1999.
Reference
[15] G.M. Sheldrick, SADABS: Empirical Absorption Correction Program, University
of Göttingen, Göttingen, Germany, 1997.
[
[
16] XPREP, Version 5.1; Siemens Industrial Automation Inc., Madison, WI, 1995.
17] G.M. Sheldrick, SHELXTL Reference Manual, Version 5.1; Bruker AXS, Madison,
WI, 1997.
18] G.M. Sheldrick, SHELXL-97: Program for Crystal Structure Refinement,
University of Göttingen, Göttingen, Germany, 1997.
19] M.A. Spackman, P.G. Byrom, Chem. Phys. Lett. 267 (1997) 215–220.
20] J.J. McKinnon, M.A. Spackman, A.S. Mitchell, Acta Cryst. B60 (2004) 627–668.
21] S.K. Wolff, D.J. Grimwood, J.J. McKinnon, D. Jayatilaka, M.A. Spackman,
CrystalExplorer 2.0, University of Western Australia, Perth, Australia, 2007.
22] F.H. Allen, O. Kennard, D.G. Watson, L. Brammer, A.G. Orpen, R.J. Taylor, Chem.
Soc. Perkin Trans. 2 (1987) S1–S19.
[
[
1] A.T. Hulme, R.W. Lancaster, H.F. Cannon, CrystEngComm 8 (2006) 309–312.
2] C. Guguta, I. Eeuwijk, J.M.M. Smits, R. de Gelder, Cryst. Growth Des. 8 (2008)
8
23–831.
[
[
[
3] R. Bansal, S. Guleria, S. Thota, S.L. Bodhankar, M.R. Patwardhan, C. Zimmer,
R.W. Hartmann, A.L. Harvey, Steroids 77 (2012) 621–629.
[
[
[
4] D.V. Banthorpe, B.V. Charlwood, in: Specialist Periodical Reports, Terpenoids
and Steroids, vol. 4, The Chemical Society, London, 1974, pp. 250–300.
5] L.F. Fieser, M. Fieser, Steroids, Reinhold, New York, 1959 (Chapters 17 and 19).
6] G.M. Sheldrick, E. Oeser, M.R. Caira, L.R. Nassimbeni, R.A. Pauptit, Acta Cryst.
B32 (1976) 1984–1987.
[
[
[
[
[
[
7] M.A. Spackman, J.J. McKinnon, CrystEngComm 4 (2002) 378–392.
8] (a) J.J. McKinnon, D. Jayatilaka, M.A. Spackman, Chem. Commun. (2007) 3814–
23] M.J. Frisch et al., Gaussian 03, Revision E.01, Gaussian Inc., Wallingford CT,
2004.
3
816;
[
[
24] E. Pidcock, Chem. Commun. 27 (2005) 3457–3459.
25] N.M. O’Boyle, A.L. Tenderholt, K.M. Langner, J. Comput. Chem. 29 (2008) 839–
(
(
b) H.F. Clausen, M.S. Chevallier, M.A. Spackman, B.B. Iversen, New J. Chem. 34
2010) 193–199.
845.
[
9] S.K. Seth, I. Saha, C. Estarellas, A. Frontera, T. Kar, S. Mukhopadhyay, Cryst.
Growth Des. 11 (2011) 3250–3265.
[
[
[
[
[
[
26] B. Kosar, C. Albayrak, Spectrochim. Acta A 78 (2011) 160–167.
27] G.U. Bublitz, S.G. Boxer, Annu. Rev. Phys. Chem. 48 (1997) 213–242.
28] J.O. Verbal, L.P. Londono, J. Chem. Inf. Comput. Sci. 42 (2002) 1241–1246.
29] T.V. Nguyen, D.W. Pratt, J. Chem. Phys. 124 (2006) 1216–1219.
30] W. Kaminsky, J. Appl. Cryst. 38 (2005) 566–567.
[
[
10] (a) A.L. Rohl, M. Moret, W. Kaminsky, K. Claborn, J.J. Mckinnon, B. Kahr, Cryst.
Growth Des. 8 (2008) 4517–4525;
(
b) A. Parkin, G. Barr, W. Dong, C.J. Gilmore, D. Jayatilaka, J.J. Mckinnon, M.A.
Spackman, C.C. Wilson, CrystEngComm 9 (2007) 648–652.
11] (a) Shamsuzzaman, H. Khanam, A. Mashrai, M. Ahmad, Y.N. Mabkhot, W. Frey,
N. Siddiqui, J. Cryst. Growth 384 (2013) 135–143;
31] W. Kaminsky, J. Appl. Cryst. 40 (2007) 382–385.