Synthesis, spectral characterization (FT-IR, NMR, XRD) and computational studies of chloroacetyl chloride incorporated 3t-butyl-2r,6c-diphenyl/di(thiophen-2-yl)piperidin-4-ones

Article abstract of DOI:10.1016/j.molstruc.2019.127076

N-chloroacetyl-3t-butyl-2r,6c-diphenylpiperidin-4-one 3 and N-chloroacetyl-3t-butyl-2r, 6c-di(thiophen-2-yl)piperidin-4-one 4 were synthesized and characterized by elemental, FT-IR and NMR analyses. The confirmation of structure 3 is elucidated by single crystal XRD analysis. The study disclosed that the spatial structure of the title crystal adopts boat conformation. Hirshfeld surfaces and fingerprint plots are used to find and analyze the percentage of intermolecular interactions and their relative significance with regard to one another. The synthesized compounds 3 and 4 were subjected to Density Functional Theory (DFT) for additional understanding of the molecular design and optoelectronic properties. Facts concerning with charge density distribution and site of chemical reactivity of the molecule are obtained by Mulliken and molecular electrostatic potential (MEP) analyses. Density functional theory computations of the HOMO-LUMO energy gaps and natural bond orbital (NBO) were successfully evaluated.

Full text of DOI:10.1016/j.molstruc.2019.127076

Journal Pre-proof
Synthesis, spectral characterization (FT-IR, NMR, XRD) and computational studies of
chloroacetyl chloride incorporated 3t-butyl-2r,6c-diphenyl/di(thiophen-2-yl)piperidin-4-
ones
M. Arockia doss, G. Rajarajan, E. Dhineshkumar, S. Amala, V. Thanikachalam, S.
Selvanayagam, B. Sridhar
PII:
S0022-2860(19)31176-7
DOI:
https://doi.org/10.1016/j.molstruc.2019.127076
MOLSTR 127076
Reference:
To appear in: Journal of Molecular Structure
Received Date: 19 November 2018
Revised Date: 30 August 2019
Accepted Date: 12 September 2019
Please cite this article as: M. Arockia doss, G. Rajarajan, E. Dhineshkumar, S. Amala, V.
Thanikachalam, S. Selvanayagam, B. Sridhar, Synthesis, spectral characterization (FT-IR, NMR,
XRD) and computational studies of chloroacetyl chloride incorporated 3t-butyl-2r,6c-diphenyl/
di(thiophen-2-yl)piperidin-4-ones, Journal of Molecular Structure (2019), doi: https://doi.org/10.1016/
j.molstruc.2019.127076.
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Synthesis, spectral characterization (FT-IR, NMR, XRD) and computational studies of
Chloroacetyl chloride incorporated 3t-butyl-2r,6c-diphenyl/di(thiophen-2-yl)piperidin-4-ones
a,b
a
a
a
a
M. Arockia doss , G. Rajarajan* , E. Dhineshkumar , S. Amala , V. Thanikachalam ,
c
d
S. Selvanayagam and B. Sridhar
a
Department of Chemistry, Annamalai University, Annamalainagar 608 002, India.
Department of Chemistry, St. Joseph University, Nagaland -797 115, India.
PG & Research Department of Physics, Government Arts College, Melur - 625 106, India.
Laboratory of X-ray Crystallography, Indian Institute of Chemical Technology, Hyderabad -
b
c
d
5
00 067, India.
*
Corresponding author: E-mail: rajarajang70@gmail.com
Abstract
N-chloroacetyl-3t-butyl-2r,6c-diphenylpiperidin-4-one 3 and N-chloroacetyl-3t-butyl-2r,
c-di(thiophen-2-yl)piperidin-4-one 4 were synthesized and characterized by elemental, FT-
6
IR and NMR analyses. The confirmation of structure 3 is elucidated by single crystal XRD
analysis. The study disclosed that the spatial structure of the title crystal adopts boat
conformation. Hirshfeld surfaces and fingerprint plots are used to find and analyze the
percentage of intermolecular interactions and their relative significance with regard to one
another. The synthesized compounds 3 and 4 were subjected to Density Functional Theory
(DFT) for additional understanding of the molecular design and optoelectronic properties.
Facts concerning with charge density distribution and site of chemical reactivity of the
molecule are obtained by Mulliken and molecular electrostatic potential (MEP) analyses.
Density functional theory computations of the HOMO-LUMO energy gaps and natural bond
orbital (NBO) were successfully evaluated.
Keywords: Piperidin-4-ones, Single crystal XRD, NBO, HOMO –LUMO.
1
. Introduction
The piperindin-4-ones class of synthetic origin has a broad and played an
extraordinary role in chemistry due to their enormous practical usefulness, primarily, owing
to a very wide spectrum of biological activities [1-6]. In addition, several interesting
investigations like corrosion [7], photophysical [8,9] and non-linear optical [10-13] studies
have been also carried out with piperidin-4-one based heterocyclic compounds. Literature

reports disclosed that blocking of nitrogen in piperidin-4-one by alkyl, formyl, chloroacetyl
chloride, nitroso, benzoyl, etc., had good advantages than unblocked compounds. As seen
from literature, N-methyl derivatives of some piperidin-4-one were found to exert diverse
antimicrobial [14-16] and antioxidant [17] properties. Similarly, the morpholine containing
piperidin-4-one [18] compounds are used as antituberculosis drugs. Also, chloroacetyl moiety
is versatile synthetic intermediate and is used as building blocks for the number of
pharmacologically active compounds. Recently, the researcher studied the incorporation of
formyl, chloroacetyl chloride, nitroso, benzoyl at the nitrogen atom of piperidin-4-one and
their confirmation has been studied by NMR data [19-24]. In view of our continuous interest
on bioactive agents, we synthesized N-chloroacetyl-3t-butyl-2r,6c-diphenylpiperidin-4-one
(N-CBDP) and N-chloroacetyl-3t-butyl-2r,6c-di(thiophen-2-yl)piperidin-4-one (N-CBDT)
by condensation of corresponding piperidin-4-one with chloroacetylchloride. The synthesized
1
13
compounds are characterized by elemental, FT-IR, H and C NMR analyses. The well-liked
conformation of compound 3 is determined by single-crystal XRD analysis. Additionally, the
optoelectronic properties of compounds 3 and 4 were studied with help of DFT analysis.
2
. Experimental
2
.1. Materials and methods
The essential materials used were of the high purity of a analar grade. Melting points
were obtained on an open capillary and are uncorrected. The FT-IR spectrum of the
-1
synthesized title compound was taken in accumulated scan 64 with 4 cm resolution,
-1
4
000-400 cm range on a AVATAR-330 FT-IR spectrometer (Thermo Nicolet) using KBr
1
13
(
pellet form). HNMR was recorded on a Bruker 400 MHz NMR and CNMR were recorded
on a Bruker 100 MHz NMR. Chemical shifts were reported in ppm. TMS (Tetramethylsilane)
that is employed as an interior reference for all NMR spectra. The chemical shifts are
reported in δ units (parts per million) relative to the standard.
2.2. Synthesis of N-Chloroacetyl-3t-butyl-2r,6c-diphenyl/di(thiophen-2-yl)piperidin-4-ones
In a round bottom flask, dry ammonium acetate (1.0 equiv), 2-heptanone (1.0 equiv)
and benzaldehyde/thiophene-2-carboxaldehyde (2.0 equiv) were dissolved in 50 mL ethanol.
Then, the reaction mixture was allowed to stir at room temperature for 24 h. After the
completion of the reaction, the solvents were evaporated. The precipitated of 3t-butyl-2r,6c-
diphenyl/di(thiophen-2-yl)piperidin-4-ones (3 and 4) were recrystallized from ethanol.

To a well-stirred solution of the respective 3t-butyl-2r,6c-diphenyl/di(thiophen-2-
yl)piperidin-4-ones (0.05 mol) and triethylamine (0.05 mol) in benzene, chloroacetyl chloride
(0.05 mol) in benzene were added in drop wise for about half an hour, the solution was
continue stirring using a magnetic stirrer. The progress of the reaction was monitored by thin
layer chromatography. After the completion of reaction, it had been poured into water and
extracted with chloroform. The collected chloroform extracts were then washed well with 3%
baking soda solution and dried over anhydrous sodium sulphate. The crude products, thus
obtained were purified by column chromatography victimisation hexane: ethyl acetate within
the ratio 9:1 (v/v) as eluent.
2
.2.1. N-Chloroacetyl-3t-butyl-2r,6c-diphenylpiperidin-4-one (3)
Yield (%): 84; m.p (°C): 120-123; MF: C H ClNO : Elemental analysis: Calcd (%):
2
3
26
2
C, 71.96; H, 6.83; N, 3.65: found(%): C, 71.81; H, 6.85; N, 3.53.
2
.2.2. N-Chloroacetyl-3t-butyl-2r,6c-di(thiophen-2-yl)piperidin-4-one (4)
Yield (%): 83; m.p (°C): 105-109; MF: C H ClNO S : Elemental analysis: Calcd
1
9
22
2
2
(%):57.63; H, 5.60; N, 3.54; S, 16.20: found (%): 57.60; H, 5.45; N, 3.40; S, 16.13.
2
2
.3. X-ray crystallography
.3.1. Intensity Data Collection
Accurate unit cell parameters and orientation matrix were obtained by a least-squares
mach of many high angle reflections within the range 2.4° ≤ θ ≤ 28.4° victimization Mo Kα
radiation on Bruker SMART APEX CCD area detector victimization ω scan mode. Cell
refinement and data reduction were carried out victimization the SAINT program. A total of
4
6797 reflections were collected, resulting in 10023 independent reflections had I > 2σ (I)
and these were through of as discovered. The intensities were corrected for Lorentz and
polarization effects.
2
.3.2. Structure solution and refinement
The structure was solved by direct ways procedure as enforced within the SHELXS97
program. The position of all the non-hydrogen atoms was enclosed within the full-matrix
least-squares refinement victimization the SHELXL2014 program. After few cycles of
anisotropic refinement, H atoms were placed in idealized positions and allowed to ride on
their parent atoms, with C-H distances of 0.93-0.98 Å, and U (H) = 1.5Ueq(C for methyl H)
iso

and U (H) = 1.2Ueq(C) for other H atoms. The bond length C21’-C22’ and C22’-C23’ was
iso
restrained to a value of 1.54 (1) Å. The refinement converged to final R-factor of 7.2%. The
residual electron density within the final difference Fourier maps has most and minimum
3
values of 0.920 and -0.457 eǺ . CCDC 1502783 contains the supplementary crystallographic
data for the title compound. These data will be obtained from free charge at the Cambridge
Crystallographic Data Centre (CCDC) via www.ccdc.cam.ac.uk/data_request/cif.
2
.4. Computational details
The synthesized compounds (N-CBDP and N-CBDT) have been optimized using the
DFT/B3LYP method using 6-31G(d,p) basis set without any symmetry restrictions. The
optimized structural parameters were used for the calculation of vibrational wavenumbers for
both compounds by a similar level theory. Here, due to the anharmonicity effect, the
calculated vibrational frequencies were scaled by using a factor of 0.9608 [25]. Moreover, the
Mulliken charge distribution and the molecular electrostatic potential (MEP) surface were
calculated and discussed. The NBO analysis was performed to understand the intramolecular
interactions present in the title compounds. The molecular orbital energies like HOMO and
LUMO for synthesized compounds were calculated by victimization a similar level theory.
NMR chemical shifts were calculated on the optimized geometries using the GIAO method at
the 6-311+G(2d,p) level theory. All calculations were performed by victimization the
Gaussian 03W [26] program package on a private computer.
3
. Results and discussion
The synthetic pathway of title compounds is delineating in Scheme 1. Compounds 3 and
1
13
4
have been characterized by elemental analysis, FT-IR, H and C NMR spectral
techniques. For compound 4, single-crystal X-ray diffraction analysis has conjointly been
recorded.
3
.1. IR spectral assignment of compound 3
The FT-IR wavenumbers were determined by utilizing B3LYP with 6-31G(d,p)
calculation. The experimental and simulated IR spectra for compound 3 are given in Figs.
S1(a&b). In Table 1, we have gathered the calculated and FT-IR experimental vibrational
wavenumbers alongside PED assignments.
3
.1.1. Aromatic vibrations

-1
The band in IR at 3018 cm is referred to C-H extending vibrations of 3. DFT
-1
calculations anticipate this mode at 3021 cm (mode no.: 152) demonstrated great
concurrence with the experimental band. This mode is absolutely an stretching mode and is
-1
obvious from the PED segment. The FT-IR band perceived at 1494 and 1455 cm of 3 and its
-1
comparing theoretical band are distinguished at 1447 and 1380 cm (mode nos: 121 and 112).
-
The C-H in-plane bending vibrations more often than not happens in the locale 1390-990 cm
1
-1
[
27]. In this manner, the IR groups at 1494, 1455, 1386, 1206, 1133, 1033 cm and its
-1
relating DFT values in the interval 1447-954 cm (mode nos: 121-69). The bands at 937, 795
-1
and 765 cm are imputed to out-of-plane bending and it is computed anticipated
-1
wavenumbers are 934, 796 and 765 cm (mode nos: 66, 52 and 49 ) by B3LYP basis set.
3
.1.2. Methyl and methylene group vibrations
For the most part, the Methyl and methylene C-H stretching frequencies of the
-1
aliphatic region are seen around 3050-2775 cm [28]. In compound 3, the comparative
-1
absorption bands at 2959 and 2866 cm are refered to the aliphatic C-H stretching
frequencies. The theoretically figured frequencies for the vibrations appeared in the hole
-1
2
988-2832 cm (mode nos: 142-128). These vibrations are upheld by PED values. The
-1
experimental vibration band at 1386 cm (FT-IR) is appointed to –CH – scissoring mode.
2
-1
The determined value appeared at 1380 cm (mode no.: 112). It has upheld by great PED
-1
esteem (85%). The rocking method of –CH – is tentatively seen in 1259 and 1206 cm and
2
-1
these groups are theoretically bolstered by 1260 and 1207 cm (mode nos.: 99 and 92).
Furthermore, it has significant PED values. The out-of-plane bowing mode, for example,
wagging and twisting modes of –CH – are observed lowere frequency region portion of
2
Table 1.
3
.1.3. C=O vibrations
The strong and intense absorption band at 1722 cm for compound 3 is owing to the
-1
-1
keto carbonyl group. The gas-phase esteem 1730 cm (mode no: 127) by B3LYP is in
accordance with test esteems. The PED investigation demonstrates a 90% commitment. The
-1
free N-C=O stretching shows up in the range 1640-1690 cm [27]. As observed from writing
29], a similar band in compound N-dichloroacetyl-c-3,t-3-dimethyl-r-2,c-6-bis(2-
[
-1
Chlorophenyl)piperidin-4-one shows at 1689 cm . In this present examination, the amide
-1
carbonyl pinnacle is recognized at 1649 cm and it all around coordinated with the calculated
value. This proclaiming frequency is because of hydrogen bonding. When shaping C-H….O

hydrogen bond, the electronic charge is discharged from the C=O bond to the C-H bond.
Henceforth, it prompts decline in C=O frequency. This is comparative with a past FT-IR
study [30], in N-acyl r-2,c-6-bis(4-methoxyphenyl)-c-3,t-3-dimethy/piperidin-4-ones the
-1
amide band was seen in the interim 1639-1657 cm .
.1.4. C-Cl vibrations
The C-Cl absorption is seen in the wide-area somewhere in the range of 850 and 550
3
-1
-1
cm [27]. In perspective on this, the FT-IR band at 795 cm is attributed to the C-Cl
extending of 3. This task is very much concurred with the theoretically determined band at
-1
7
96 cm with impressive PED esteem. The C-Cl in-plane and out of plane bending vibrations
are obtained at a low-frequency region. Extra help for the task of bands of the compound
originates from the connection among's theoretical and experimental wave numbers. As
observed in from Fig. S2 speaks to an awesome linear relationship and standard deviation
among theoretical and experimental wave numbers of compound 3.
3
.2. IR spectral assignment of compound 4
3
.2.1. Aromatic ring vibrations
-1
The Infrared band comes into view at 3056 cm as a C-H extending mode.
-1
Theoretically, this vibration is seen at 3077 cm (mode no.: 135). The PED comparing to this
vibration is an pure mode and precisely contributes about 94%. The stretching vibrations of
-1
the thiophene ring showed up at 1493 cm (FT-IR). The B3LYP counts give this mode at
-1
1
506, 1418, 1415, 1410 and 1301 cm . (mode nos.: 110, 106, 105, 104 and 94) and its PED
-1
commitment 45-13%. The in-plane IR bending mode at 1255, 1214 and 1075 cm and it's
-1
comparing gas-phase esteems are 1263, 1210 and 1081 cm (mode nos.: 90, 85 and 76).
-1
These values are mached with the experimental proof. The bands at 841, 795 and 760 cm
are assigned to out-of-plane bowing and it is hypothetically anticipated wavenumbers are
-1
8
50, 796 and 765 cm (mode nos: 58, 52 and 51 ) by B3LYP.
3
.2.2. Methyl and methylene group vibrations
The compound 4 has methyl (–CH ) and methylene (–CH –) groups. The particular
3
2
-1
C–H stretching band is seen at 2963, 2935 and 2873 cm . The theoretical vibrations for this
-1
band appeared in the region 2970-2839 cm (mode nos: 129-114). These vibrations are
-1
upheld by PED values. The FT-IR vibration band at 1382 and 1362 cm is imputed to –CH –
2
-1
scissoring mode. The calculated an incentive at 1390 and 1368 cm (mode nos.: 102 and

-1
1
09). The rocking mode of –CH – is tentatively seen in 1255 and 1171cm and these bands
2
-1
are theoretically reinforced by 1263 and 1081 cm (mode nos.: 90 and 76). The out-of-plane
bending mode, for example, wagging and twisting modes of –CH – groups are observed in
2
lower frequency values are given in Table S3.
3
.2.3. C=O vibrations
The strong band at 1712 cm for compound 4 is dependable to keto group in
-1
-1
piperidin-4-one ring. The unadulterated gas-phase esteem 1725 cm (mode no: 113) is in
accordance with experimental esteems. The PED examination demonstrates a 91%
-1
commitment. The amide carbonyl peak is experimentally perceived at 1642 cm and it very
much coordinated with the calculated value.
3
.2.4. C-Cl vibrations
As observed from the Table S3, the C-Cl band is distinguished at 738 cm . This
-1
-
1
assignment is concurred with the theoretically determined band at 765 cm (mode no.: 49).
The C-Cl in-plane and out of plane bowing vibrations are acquired at a low-frequency region.
The observed and computed IR spectra of compound 4 are appeared in Figs. S3(a&b).
Notwithstanding the great understanding between the experimental and calculated
information, true to form the theoretical wavenumbers are marginally overestimated, mostly
because of the exclusion of anharmonicity. As observed in from Fig. S4 speaks to an
awesome linear relationship and standard deviation among theoretical and experimental wave
numbers for compound 4.
3
.3. NMR spectral assignments
1
The experimental and calculated H NMR chemical shift values are tabulated in
1
Table 2. In H NMR spectrum of compound 3, the downfield signals within the vary
7
.06-7.30 ppm of phenyl group are assigned to aromatic protons within the phenyl groups at
C1 and C5 positions. Two broad signals at 6.12 and 5.48 ppm are due to protons at C5 and
C1, respectively. The broadening of benzylic protons arises as a result of restricted rotation
concerning N-CO bond and also the in-plane nature of the substituted at the heterocyclic
nitrogen of piperidone moiety with the dynamically average plane of the piperidone [21]. The
methylene protons of chloroacetyl moiety appeared at 3.92 ppm. The signal at 3.13 ppm is
assigned to H2A proton. The upfield signal at 2.88 and 2.68 ppm are assigned to H4 and H2B

protons, respectively [21]. The multiplet within the vary 1.25-1.68 corresponds to methylene
protons at C4 butyl group. The triplet at 0.90 ppm is assigned to methyl protons of the butyl side
1
chain at the C4 position. The similar splitting patterns were observed for compound 4. The H
NMR spectra of compounds 3 and 4 are given in Figs. S5 and S6.
1
3
The experimental and calculated C NMR chemical shift values are tabulated in
1
3
Table 3 and spectra are given Figs. S7 and S8. In the C NMR spectra of compounds 3 and
, there are two downfield signals at 207.81, 207.83 and 169.26, 168.03 ppm of compound 3
4
and 4. These are characteristic for ring carbonyl carbon at C3 and C12 (amide carbon),
respectively. The signals in the region 126.01-143.84 ppm are due to aromatic carbons. Two
signals at 59.04, 62.35 and 56.86, 58.38 ppm corresponds to C5 and C1 carbons, respectively
for compound 3 and 4. Similarly, the signals at the vary 53.01, 50.60 ppm are responsible for
carbon at C4 positions. The signals of piperidone moiety at 46.78, 47.12 ppm are assigned to
methylene carbons at C2. Signals at 42.60, 42.53 ppm are ascribed to methylene carbon
(
C13) of N-substituted chloroacetyl moiety. Compounds 3 and 4, the signals within vary
2.41-32.28 ppm are assigned to methylene carbons within the position of C4. The most
upfield signals observed ca. 13.80 ppm are assigned to methyl carbon in butyl side chain at
2
1
3
C4. The above results revealed that C NMR spectrum of compound 4, C5, and C1 carbon
13
are deshielded when compound with C NMR spectrum of compound 3 this is due to more
electronegative atom consisting in aromatic ring attached to C5 and C1 position. The
predicted chemical shift values are in good agreement with the experimental values.
1
13
The linear regression between the experimental and theoretical H and C NMR
chemical shifts of title compounds are represented in Figs. S9 and S10, respectively. In the
1
13
present study, the following linear relationships are obtained for H and C and chemical
shifts
1
For H
2
δCal. = 0.10757+1.01431 δExpt. (R =0.99906; SD=2.11) for compound 3
2
δCal. = 0.15887+1.01103 δExpt. (R =0.99766; SD=1.50) for compound 4
1
3
For C
2
δCal. = 0.17195+1.01505 δExpt. (R =0.99996; SD=5.67) for compound 3
2
δCal. = 1.0134 δExpt.- 0.23126 (R =0.99999; SD=3.07) for compound 4

3
.4. Single crystal X-ray diffraction analysis of compound 3
The crystal data, intensity information assortment and refinement details for compound
3
are summarized in Table 4. The corresponding bond lengths and bond angles are tabulated
in Table 5. Table S1 provides the hydrogen bonds concerned within the structure. Fig. 1
shows the ORTEP of the molecule drawn at 30% probability thermal displacement ellipsoids
with the atom numbering scheme. The asymmetric unit contains two molecules (Fig. 2); their
corresponding bond lengths and bond angles are insensible agreement. Fig. S11 shows a
superposition of the piperidine ring of each the molecules victimization Q mol; the r.m.s. the
deviation is 0.016 Å. The superposition of the piperidine ring of the current structure with the
connected structure N-chloroacetyl-3t-butyl-2r,6c-diphenyl piperidin-4-one (except C24)
structures (Fig. S11) victimization Q mol, gives r.m.s. deviations of 0.531 Å, for molecules A
and B.
The total of the angles at N1 [358.6˚ (molecule A) and 358.5˚ (molecule B)] is in
2
accordance with sp hybridization. Two phenyl rings are in planar with the most deviation of
0
.014 (4) Å for atom C17’. These two phenyl rings are destined with a dihedral angle of 80.2
(1) and 77.4 (1)˚, in the order mentioned, with regard to another for molecules A and B. The
phenyl ring (C14-C19) is sort of perpendicular to the best plane of the piperidine ring with a
dihedral angle of 86.5(4)˚ in molecule A and 87.9 (1)˚ in molecule B. The 3-butyl group
(C20-C24) is in planar with the most deviation of -0.021 (6) Å for atom C23 in molecule A
and -0.090 (12) Å in molecule B.
The piperidine ring adopts a boat conformation in both molecules A and B. the
puckering parameters are: q = 0.663 (2) Å = Q q = -0.043 (2) Å, and θ = 86.3 (2)˚, atom
2
T,
3
C2 and C5 deviate by -0.537 (2) and -0.571 (3) Å, respectively from the least-squares plane
through the remaining four atoms in molecule A; q = 0.662 (2) Å = Q q = 0.063 (2) Å, and
2
T,
3
θ = 84.6 (2)˚, atom C2 and C5 deviate by 0.503 (2) and 0.576 (3) Å, respectively from the
least-squares plane through the remaining four atoms in molecule B.
In addition to Van der Waals interactions, the molecular structure is influenced by
…
five C-H O intramolecular hydrogen bonds as shown in Fig. 3. within the crystal, molecules
…
associate via C-H O hydrogen bonds involving atoms H1 and H13B at (x,y,z) and O1 at
x,1+y,z) into chains within the unit cell which runs in diagonal to the ac plane of the unit
cell. In addition to this, molecules associate via another C-H···O hydrogen bonds link the
(

molecules in [001] direction of the unit cell; see Fig. 4. The similar Van der Waals
interactions were observed between C3-H3...O2 with 2.38Å in r-2, c-6-bis(2-Chlorophenyl)-
t-3,t-5-dimethyl-N dichloroacetylpiperidin-4-one [28]. This value well matched with our
crystal 3.
3
.5. Hirshfeld surface analysis of Crystal 3
The Hirshfeld surface mapped over dnorm is shown in Fig. 5. The surfaces are exposed
as transparent to allow visualization of the molecular moiety, in a similar orientation for
structures, around which they are calculated. The dominant interaction involving chemical
element (O) and chemical element (H) atoms will be noticed within the Hirshfeld surface
because of the red areas (Fig. 5).
The plots between d vs d referred to as finger plots, which are useful in identifying
i
e
and comparing different kinds of interactions [33,34]. This study displays all possible
.
..
...
...
...
interaction types: the fundamental such as C-H O, H H, C H, and Cl H contacts. It is
evidenced by Figs. 6a-f. Matta et al. [35] analyzed ubiquitous hydrogen-hydrogen bonding
by the quantum theory of atoms in molecules and found that they are stabilizing interactions
.
..
in crystal packing. Interestingly, H H contacts were found to become extremely prominent
at high pressures in surface fingerprint plots. Figs. 6a-f shows the major contribution (64.1%)
.
..
of the dihydrogen contacts (H H) within the fingerprint plot [36].
.
..
The contribution of the chemical bond (C-H O) appears on the Hirshfeld surface of
the molecule (Fig. 6d) with a percentage of 15.4 over the total interactions. Certainly, in our
study close contacts between pairs of electronegative Cl atoms interact with neighboring H
.
..
atoms (Cl H) with the amount of 4.8 % towards the total contributions. In addition,
.
..
fingerprint plot also finds C H interaction about 8.0% towards total contribution.
3
3
.6. Theoretical studies
.6.1. Molecular geometry
As proof from single-crystal structure analysis, we find that boat conformation was
more stable. Hence, in this study, we took same for further analysis. The optimized structural
parameters like as bond lengths, bond and dihedral angles of 3 and 4 were determined at
B3LYP level theory with 6-31G(d,p) basis set and are presented in Table S2 and also the
optimized structure of compounds are shown in Fig. 7.

The calculated C-C bond distances in the piperidine ring are within the vary 1.519-
.555 Å by nearly coincides with experimental value 1.492(3)-1.540(3) Å. Calculated
1
findings have been found to differ slightly from experimental values. Since the theoretical
calculations belong to the molecule at the gaseous phase, while the experimental results
belong to molecules in the solid-state. This difference is actually due to the experimental
value corresponds to the intermolecular columbic interaction with the adjacent molecules in
the solid-state. The N1-C5 and N1-C1 bond nearly ~1.49 Å by B3LYP, that coincides with
experimental value ~1.488 Å. The bond lengths Cl1-C12 [~1.815 (DFT) & ~1.765 Å (XRD)]
make sure the single bond character. By comparing these values with the reported value [10]
and crystal value, it is predicted that the bond lengths O1-C3 and O2-C12 confirm the double
bond character. The average bond angles at C1-N1-C5 [~118 (DFT) & ~119˚ (XRD)] is in
2
accordance with sp hybridization. Piperidine ring essentially adopts a boat conformation as
evident from the torsional angles [N1–C5–C4–C3 and N1–C61–C2–C3]. 60.5˚ and 56.5˚
(
DFT) values conceders with experimental value 55.3˚.
.6.2. NBO analysis
NBO analysis offers helpful insights on the intramolecular delocalization and donor-
3
acceptor interactions supported the second-order interactions between stuffed and vacant
orbitals. It’s fascinating to grasp the necessary state stabilization interactions that create the
molecules to be stable within the ground state [37,38]. NBO analysis has been meted out and
also the results are summarized in Table 6. This table lists the most important second-order
perturbation interactions along with the corresponding donor and acceptor NBOs.
The delocalization of σ electron from σ (C1-C2) distributes to antibonding σ*(C3-O1)
leading to the stabilization energy of 9.46 and 8.58 kcal/mol for compound 3 and 4,
respectively. The strong intramolecular hyperconjugative interaction of the σ electron of
C12-O2 distributes to σC5-N1 (ca.9.37 kJ/mol) and also the different hand, the π C12-O2
electron conjugate to the anti-bonding orbital σC13-Cl1 with energy ca.13.89 kJ/mol. The
LP(2)O1 is interacting with neighboring bonds like C3-C4 and C2-C3 with the energies
~72.01, 70.48 and 86.78 kJ/mol, respectively. The LP(2)O2 is contributing to the energies by
~88.07, 88.82, 67.28, 67.78 and 3.68, 3.26 kJ/mol with σ N1-C12, C12-C13, and C13-Cl1.
The strong intra-molecular hyperconjugative interaction of C12-O2 from N1 of
LP(1)N1→π * C12-O2 that resulting in stabilization of ca. 255.60 kJ/mol of compounds. A
strong interaction was observed as a result of the electron density transfer from the lone pair

LP (3) Cl1 to π*(C12-O2) with a large steadying energy of 17.18 and 16.77 kcal/mol for
compound 3 and 4, respectively.
3
.6.3. Mulliken charge analysis
The calculation of atomic charges plays a crucial role within the application of
quantum mechanical calculations to molecular systems [39,40]. Supported on the charge
distribution calculation it will be over that each one the hetero atoms showed significant
electron density. The Mulliken charge analysis has been meted out and also the results are
tabulated in Table S4. As presumed in Table S4, an increased electron density (negative
charge) can be also found within the N1, O1, O12, and C12. The negative regions of the
studied molecule are found around the N1 and O atoms, thus electrophilic attack will happen
to N1 and O atoms. The carbon atom C12 possesses differ charge pattern from other carbons,
which may be the reason for an adjacent electronegative chlorine atom. The significantly
positive charge was predicted on C3, C12, H13A, and H13B atoms. Supported the discussion,
we tend to conclude nucleophile is favored especially on carbonyl carbons (C3 and C12).
3
.6.4. MEP analysis
In order to search out potential non-covalent interactions sites are in any given
molecule, the MEP might be a useful tool. Significantly, the calculation of relative reactivity
sites for electrophilic and nucleophilic reactions, hydrogen bond donor and acceptor sites,
investigation of biological recognition and prediction of a variety of macroscopic properties
will be done by MEP [41,42].
The 3D plots of the MEPs for compounds 3 and 4 are presented in Fig. S12. The
electrostatic potentials at the surface of 3 and 4 are shown in different colors. From Fig. S12,
it is evident that the negative regions localized over the oxygen atoms of the carbonyl groups.
For the atoms H13A and H13B, respectively, have positive potential due to the influence of
the chlorine atom. The negative regions (red) are associated with electrophilic reactivity and
the positive (blue) regions to nucleophilic reactivity. As we conclude that title molecules are
ready to involve both electrophilic and nucleophilic substitution reactions.
3
.6.5. HOMO-LUMO analysis
For optical and electronic characterization, the HOMOs, LUMOs and energy gaps
(ꢀEH–L) are examined [43,44]. The frontier molecular orbitals play a crucial role within the

electrical and optical properties, also as well as in chemical reactions. Visualization of orbital
energies for title compounds are shown in Fig. 8. So as to ascertain the precise electronic
structure we tend to performed HOMO-LUMO analysis by B3LYP level theory with
6
-31G(d,p) basis set.
The molecular orbital energies are displayed in Fig. 8. As seen from Table S5, the
HOMO-LUMO gap lie 5.56 and 5.32 eV for compounds 3 and 4, respectively. The energy
gap is found to be a maximum of 4 and a minimum of 3. As seen in from above results the
decreasing trend of ꢀE gap of examined compounds becomes 3 > 4. From the trend, it will be
noted that the substitution of the thiophene ring instead of the phenyl group in compound 3.
Further incorporation of the chloroactyl moiety in compound 3 further reduces energy gap.
Among the investigated compounds 3 and 4, the donor types 4 has the lowest energy gap and
are considered to be appropriate candidates for electronic applicants and additional need
structural modification to enhance their luminescence ability. Therefore, it’s clear that the
power of the charge injection becomes enhanced from 3 and 4. These findings suggest that
electron releasing groups have little effect on the band gap whereas the electron withdrawing
groups reduce them to a higher degree. As seen from our previous report [44], the similar
piperidin-4-one derivative exhibited band gap at 5.06 eV (245nm). This value well-matched
with theoretically predicted energy gap of compounds 3 and 4.
4
. Conclusions
Overall, we synthesised of N-chloroacetyl-3t-butyl-2r,6c-diphenylpiperidin-4-one and
N-chloroacetyl-3t- butyl-2r,6c-di(thiophen-2-yl)piperidin-4-one, confirmed by FT-IR, FT-
Raman, and NMR spectral analyses. The single-crystal XRD analysis study of structure 3
revealed that the spatial structure of the title crystal adopts boat conformation. Hirshfeld
surfaces and fingerprint plots quantify the possible interactions in N-CBDP molecule. The
optimized parameters were also well reproduced by the B3LYP calculations. Molecular
reactivity behaviour is proved by using Mulliken and MEP analyses. The high value of inter
and intramolecular interactions are verified by NBO analysis. A better understanding of the
charge transfer process investigated by FMO analysis.
Acknowledgments

One of the authors, Dr. G. Rajarajan is thankful to UGC [F. No. 42-343/2013 (SR)]
for providing funds for this research study. Mr. M. Arockia doss is thankful to UGC for
providing fellowship.
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[

-1
Table 1 Observed and calculated wavenumbers (cm ) and PED assignment for compound 3
Mode
No.
Observed
frequencies (cm )
Calculated
-1
-1
frequencies(cm )
b
PED ≥10%
a
IR
Unscaled Scaled
Intensities
ΓN11-C1-C31-C46 (13)+ΓC2-C3-C5-C4 (15)+ΓC1-N11-C5-C4 (21)+ΓC2-C3-N11-C1
1
20
20
0.16
(
18)+ΓC16-C13-C3-C2 (14)
2
3
4
27
35
39
26
33
37
0.21
0.14
0.58
ΓN11-C1-C31-C46 (41)+ΓN11-C2-C38-C50 (31)+ΓC27-C25-N11-C1 (12)
ΓC16-C13-C3-C2 (47)+ΓC13-C2-C4-C3 (16)
βN11-C1-C31(11)+ΓC27-C25-N11-C1 (24)+ΓCl30-C27-C25-N11(15)
5
48
46
0.45
ΓC2-C3-C5-C4 (21)+ΓC3-C13-C16-C19 (14)+ΓC13-C2-C4-C3 (16)
6
7
8
9
63
69
61
66
2.17
0.80
0.79
1.34
0.35
1.44
1.12
0.35
2.09
2.62
2.55
1.46
1.81
0.09
0.52
0.92
3.16
1.22
2.15
3.08
βC3-C13-C16(10)+ΓC2-C3-C5-C4 (23)+ΓC38-C3-N11-C2 (13)
βN11-C1-C31(15)+ΓCl30-C27-C25-N11(10)+ΓC1-C31-C46-C32 (19)
ΓC3-C13-C16-C19 (10)+ΓC25-C1-C2-N11 (29)
ΓN11-C2-C38-C50 (17)+ΓC3-C13-C16-C19 (10)
ΓC3-C13-C16-C19 (11)+ΓC13-C16-C19-C22 (38)
βC2-N11-C25(11)+ΓC27-C25-N11-C1 (26)
ΓN11-C2-C38-C50 (10)+ΓC1-N11-C5-C4 (18)
βC13-C16-C19(15)+ΓC1-N11-C5-C4 (12)
74
71
80
77
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
81
78
89
86
113
132
158
173
190
211
215
236
247
263
272
279
304
339
109
127
151
166
182
203
207
227
237
253
261
268
292
325
βN11-C25-C27(16)+βC25-C27-Cl30(22)+ΓC27-C25-N11-C1 (14)
βC25-C27-Cl30(21)+βC1-C31-C46(12)
βC2-N11-C25(10)+βC4-C3-C13(30)
βC1-C31-C46(10)+βC2-N11-C25(17)
ΓC42-C40-C51-C50 (12)+ΓC2-C3-N11-C1 (26)
ΓC16-C19-C22-H23(25)+ΓC16-C19-C22-H45(27)
βC1-C31-C46(15)+βC16-C19-C22(16)
βC1-C31-C46(13)+βN11-C1-C5(10)
βC2-C38-C50(11)+ΓC35-C31-C47-C46 (11)
βC13-C16-C19(18)+βC16-C19-C22(23)
ΓC13-C2-C4-C3 (10)+βC1-C31-C46(13)+βC16-C19-C22(12)
ΓC35-C31-C47-C46 (10)+βN11-C1-C5(12)

2
2
2
2
3
3
3
3
3
3
3
3
3
3
4
4
4
4
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
370
390
406
411
434
460
462
488
499
515
568
605
618
620
621
643
671
691
355
375
391
395
417
442
444
469
479
495
546
581
594
595
597
618
645
664
4.68
5.06
0.21
0.03
12.36
4.12
4.52
2.30
6.21
17.59
10.43
3.52
3.26
0.55
2.38
9.64
19.22
4.77
ΓC33-C32-C35-C47 (15)+ΓC40-C39-C42-C51 (10)
βC5-C4-C3(17)+βN11-C2-C38(10)
ΓC35-C31-C47-C46 (15)+ΓC33-C32-C35-C47 (21)+ΓC40-C39-C42-C51 (13)
ΓC42-C40-C51-C50 (13)+ΓC33-C32-C35-C47 (11)+ΓC40-C39-C42-C51 (22)
βC5-C4-C3(15)+βN11-C25-C27(14)+βN11-C2-C3(11)
βC5-C4-O12 (21)+βC27-C25-O26 (10)
βC5-C4-O12 (11)+ΓC42-C40-C51-C50 (10)+ΓC2-C38-C50-C39 (13)
βC13-C16-C19(17)+βC16-C19-C22(12)
ΓC33-C32-C35-C47 (15)+ΓC40-C39-C42-C51 (12)
βC27-C25-O26 (13)+ΓC1-C31-C46-C32 (15)
βC33-C35-C47(11)+βC40-C42-C51(10)+βC32-C33-C35(15)
βC33-C35-C47(21)+ΓC31-C5-N11-C1 (11)
βC40-C42-C51(25)+βC42-C51-C50(10)
βC35-C47-C46(15)+βC40-C42-C51(11)+βC32-C33-C35(13)
βC32-C33-C35(17)+βC39-C40-C42(27)+βC42-C51-C50(18)
ΓO12-C3-C5-C4(13)+βC33-C35-C47(15)
νC27-Cl30(15)+ΓO20-C27-N11-C25(13)
ΓC42-C40-C51-C50 (13)+ΓC40-C39-C42-C51 (17)+ΓC38-C50-C42-C51 (25)
ΓC46-C47-C35-H37 (10)+ΓC31-C46-C35-C47 (27)+ΓC35-C31-C47-C46 (14)+ΓC33-C32-
C35-C47 (15)
4
4
695
668
33.15
4
4
4
4
4
5
5
5
5
5
6
7
8
9
0
1
2
3
703
705
731
759
797
801
809
828
832
675
678
703
730
766
770
777
796
800
17.77
6.68
ΓC50-C51-C42-H44 (12)+ΓC31-C46-C35-C47 (10)
βC33-C35-C47(16)+ΓC31-C46-C35-C47 (13)+ΓC35-C31-C47-C46 (17)
βC25-C27-Cl30(12)+ΓO20-C27-N11-C25(10)
18.81
7.97
ΓC13-C16-C19-H20(12)+ΓC35-C33-C32-H34 (10)+ΓC35-C47-C46-H48 (13)
ΓC35-C33-C32-H34 (10)+ΓC35-C47-C46-H48 (13)
765
795
53.06
4.41
νC27-Cl30(20)+βC25-C27-Cl30(10)+ΓO20-C27-N11-C25(17)
ΓC42-C51-C50-H52 (13)+ΓC38-C50-C51-H53 (15)
10.86
1.70
νC27-Cl30(25)+ΓC42-C51-C50-H52 (13)+ΓC38-C50-C51-H53 (12)
νC3-C13(13)+ ΓC35-C33-C32-H34 (10)+ΓC35-C47-C46-H48 (16)
3.25
ΓC35-C33-C32-H34 (19)+ΓC35-C47-C46-H48 (23)+ΓC47-C35-C33-H36 (21)+ΓC31-C46-
C47-H49 (18)
ΓC42-C40-C39-H41 (13)+ΓC42-C51-C50-H52 (23)+ΓC38-C50-C51-H53 (17)+ΓC51-C42-
5
5
4
5
837
844
804
811
0.42
0.48

C42-H43 (22)
5
5
5
5
6
6
6
6
7
8
9
0
1
2
859
873
903
911
916
932
940
825
839
867
875
880
895
903
5.48
6.83
4.80
9.24
1.87
1.54
4.13
νC16-C19(16)+ΓC47-C35-C33-H36 (10)+ΓC31-C46-C47-H49 (11)
ΓC42-C51-C50-H52 (19)+ΓC38-C50-C51-H53 (15)
νC25-C27(15)+ΓC38-C50-C51-H53 (20)+ΓC51-C42-C42-H43 (25)
ΓC35-C33-C32-H34 (24)+ΓC35-C47-C46-H48 (26)+ΓC46-C47-C35-H37 (29)
ΓC42-C40-C39-H41 (13)+ΓC42-C51-C50-H52 (19)+ΓC50-C51-C42-H44 (19)
ΓC31-C46-C47-H49 (10)+ΓC31-C46-C35-C47 (15)
νC1-N11(13)+ΓC35-C47-C46-H48 (15)+ΓC47-C35-C33-H36 (12)
ΓC35-C33-C32-H34 (22)+ΓC35-C47-C46-H48 (14)+ΓC47-C35-C33-H36 (22)+ΓC31-C46-
C47-H49 (21)+ΓC31-C46-C35-C47 (11)
ΓC42-C40-C39-H41 (21)+ΓC42-C51-C50-H52 (13)+ΓC38-C50-C51-H53 (21)+ΓC51-C42-
C42-H43 (15)+ΓC38-C50-C42-C51 (10)
6
6
3
4
951
959
914
921
0.97
0.04
6
6
6
5
6
7
964
972
975
926
934
936
13.43
0.70
0.72
ΓC42-C51-C50-H52 (17)+ΓC38-C50-C51-H53 (21)+ΓC51-C42-C42-H43 (10)
νC13-C16(12)+ΓC42-C40-C39-H41 (15)+ΓC50-C51-C42-H44 (14)
937
ΓC47-C35-C33-H36 (20)+ΓC46-C47-C35-H37 (29)+ΓC31-C46-C47-H49 (21)
ΓC42-C40-C39-H41 (12)+ΓC50-C51-C42-H44 (24)+ΓC38-C50-C51-H53 (13)+ΓC51-C42-
C42-H43 (27)
6
8
981
943
1.77
6
7
7
7
7
7
7
7
7
7
7
8
8
8
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
993
954
956
1.83
0.49
2.71
2.71
3.15
3.91
0.49
3.98
2.55
0.94
3.86
8.45
131.13
27.77
0.14
βC40-C42-C51(15)+βC39-C40-C42(21)+βC42-C51-C50(29)
νC13-C16(24)+νC2-C3(24)+βC35-C47-C46(32)+βC33-C35-C47(18)+βC32-C33-C35(12)
νC19-C22(14)+βC35-C47-C46(15)+βC33-C35-C47(10)
νC19-C22(36)+νC3-C13(10)+βC32-C33-C35(10)
νC33-C35(24)+ΓN11-C25-C27-H28 (15)
995
1021
1021
1034
1037
1060
1066
1083
1091
1098
1103
1126
1151
1161
981
981
994
997
νC42-C51(24)+νC40-C42(26)
1018
1024
1040
1048
1055
1060
1081
1106
1115
νC16-C19(16)+νC13-C16(22)+νC3-C13(15)
1033
νC1-C5(24)+ βC50-C51-H53(19)
νC32-C33(12)+ νC47-C46(15)+ βC47-C35-H37(10)
νC39-C40(12)+ βC51-C42-H44(13)+νC50-C51(14)
νC16-C19(10)+ ΓC16-C19-C22-H24(12)
νC32-C33(15)+ νC47-C46(20)+ βC47-C35-H37(12)
νC2-N11(12)++ΓN11-C25-C27-H28 (15)
ΓN11-C25-C27-H28 (16)+ΓN11-C25-C27-H29(19)
βC35-C33-H36(36)+βC46-C47-H49(21)

8
8
8
8
8
8
9
9
9
9
9
9
9
9
9
9
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
1163
1172
1180
1186
1189
1194
1207
1229
1255
1259
1259
1274
1277
1299
1301
1310
1313
1330
1331
1334
1341
1347
1359
1383
1386
1390
1396
1430
1436
1117
1126
1134
1139
1142
1147
1160
1181
1207
1211
1210
1224
1227
1248
1250
1260
1261
1278
1279
1282
1288
1294
1306
1329
1332
1336
1341
1374
1380
0.44
24.07
9.94
βC51-C42-H44(33)+βC42-C40-H43(21)
1133
νC1-C31(12)+νC2-C38(16)+βC33-C32-H34(15)
ΓN11-C25-C27-H28 (12)+ΓN11-C25-C27-H29(15)
βC33-C32-H34(18)+βC47-C46-H48(20)+βC35-C33-H36(17)+βC46-C47-H49(16)
βC50-C51-H53(12)+βC4-C5-H10 (15)
7.24
22.31
43.82
26.24
5.32
βC40-C39-H41 (10)+βC51-C50-H52 (10)
ΓC3-C4-C5-H7 (16)+βC47-C46-H48(10)+βC35-C33-H36(15)
βC4-C5-H10 (13)+ΓC3-C4-C5-H7 (11)
1206
1230
10.59
24.40
22.35
13.00
6.27
βC38-C2-H6 (12)+βC4-C9-H9 (11)+βC19-C16-H17(13)
βC31-C1-H8 (11)+βC4-C5-H10 (11)
βC4-C5-H10 (12)+βC19-C16-H17(11)
ΓN11-C25-C27-H28 (22)+ΓN11-C25-C27-H29(38)
βC38-C2-H6 (15)+βC22-C19-H20(12)+ΓC5-C4-C3-H9 (11)
βC19-C16-H17(10)+βC22-C19-H20(21)
15.51
31.28
0.78
ΓC3-C4-C5-H7 (11)+βC47-C46-H48(10)
1259
νC38-C50(13)+ νC38-C39(10)+ βC22-C19-H20(16)
βC38-C2-H6 (24)+ΓC22-C19-C16-H18(10)
1
1
1
1
1
1
1
1
1
1
1
1
1
00
01
02
03
04
05
06
07
08
09
10
11
12
17.61
5.78
νC32-C33(21)+ ΓC32-C31-C1-H8 (11)
20.73
14.88
15.64
13.47
12.74
22.40
4.06
C19-C16-C13-H14(13)+ΓC19-C16-C13-H15(11)
ΓC39-C38-C2-H6 (10)+ΓC22-C19-C16-H18(10)
βC33-C32-H34(10)+βC47-C46-H48(12)+ΓC32-C31-C1-H8 (26)
βC51-C50-H52 (12)+βC51-C42-H44(25)
ΓC5-C4-C3-H9 (11)+ΓC19-C16-C13-H14(18)+ΓC19-C16-C13-H15(16)
βC31-C1-H8 (36)+ΓC32-C31-C1-H8 (15)
ΓC22-C19-C16-H17(15)+ΓC22-C19-C16-H18(18)+ΓC13-C16-C19-H21(13)
νC25-N11(26)+ ΓC39-C38-C2-H6 (26)
136.23
1.11
βH24-C22-H23(28)+βH45-C22-H24(31)+βH23-C22-H45(31)
βH7-C5-H10 (89)
6.78
1386
24.10
βH28-C27-H29(85)
νC39-C40(14)+νC50-C51(15)+ βC51-C42-H44(25)+βC50-C51-H53(11)+βC42-C40-
H43(13)
1
13
1447
1390
8.48

1
1
1
1
1
1
1
14
15
16
17
18
19
20
1464
1466
1473
1474
1480
1488
1506
1407
1408
1416
1417
1422
1430
1447
4.86
8.02
1.17
0.54
5.73
3.27
8.62
βH15-C13-H14(10)+βH17-C16-H18(51)+βH20-C19-H21(16)
νC32-C33(10)+νC47-C46(11)+ βC47-C35-H37(19)+βH17-C16-H18(11)
βH15-C13-H14(31)+βH20-C19-H21(21)+βH24-C22-H23(17)
νC35-C47(24)+βH15-C13-H14(36)+βH17-C16-H18(22)
βH45-C22-H24(38)+βH23-C22-H45(36)+ΓC16-C19-C22-H45(15)
βH20-C19-H21(33)+βH24-C22-H23(30)+βH45-C22-H24(11)
νC35-C47(22)+ βC35-C33-H36(14)+βC42-C40-H43(13)+βC46-C47-H49(14)
νC40-C42(11)+ βC40-C39-H41 (14)+βC51-C50-H52 (15)+βC47-C46-H48(13)+βC50-C51-
H53(14)
1455
1494
1
21
1506
1447
12.12
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
1601
1606
1625
1689
1725
1800
2947
2952
2964
2970
2985
2996
3001
3005
3023
3030
3035
3040
3041
3043
3108
3110
1538
1543
1561
1623
1659
1730
2832
2837
2848
2854
2868
2878
2883
2887
2905
2911
2916
2921
2921
2924
2986
2988
0.53
0.70
νC42-C51(22)+ νC40-C42(18)+ νC38-C50(17)+νC38-C39(11)+ βC51-C42-H44(11)
νC35-C47(22)+νC31-C46(17)+νC33-C35(18)+νC31-C32(15)
νC39-C40(22)+νC50-C51(20)+ νC38-C39(11)
νC32-C33(21)+νC47-C46(21)+νC31-C46(11)+νC31-C32(10)
νC25-O26(93)
3.29
0.92
1649
1722
250.92
169.15
17.35
36.48
20.41
48.18
6.67
νC4-O12(90)
νC13-H15(13)
νC19-H20(79)+νC19-H21(10)
νC16-H17(73)+νC16-H18(12)
2866
νC22-H23(39)+νC22-H24(28)+νC22-H45(25)
νC1-H8(69) +νC5-H7(29)
7.07
νC1-H8(30) +νC5-H7(57) +νC5-H10(12)
νC13-H15(71)
12.68
11.57
12.95
8.13
νC16-H18(12)+νC19-H21(63)
νC16-H17(10)+νC16-H18(62)
νC2-H6(19) +νC3-H9(70)
10.68
57.79
12.63
39.55
5.94
νC2-H6(43) +νC3-H9(18)+νC13-H14(73)
νC22-H23(44)+νC22-H24(19)+νC22-H45(12)
νC2-H6(37) +νC27-H28 (11)+νC19-H21(14)+νC27-H29(29)
νC22-H24(39)+νC22-H45(59)
2959
νC5-H7(13) +νC5-H10(86)
0.35
νC33-H36(35)+νC35-H37(37)+νC40-H43(29)+νC47-H49(21)

1
1
1
1
1
1
1
1
1
1
44
45
46
47
48
49
50
51
52
53
3112
3116
3119
3125
3126
3132
3133
3137
3144
3158
2990
2994
2997
3002
3003
3009
3010
3014
3021
3035
0.13
9.40
νC42-H44 (40) +νC51-H53 (28)
νC33-H36(36)+νC35-H37(36)+νC47-H49(45)
νC51-H53 (46)+νC40-H43(47)
9.87
0.92
νC27-H28 (83)+νC27-H29(17)
26.51
29.78
14.05
9.53
νC32-H34 (24) + νC46-H48 (20)+νC35-H37(45)
νC50-H52 (12) + νC42-H44 (56) +νC51-H53 (11)+νC40-H43(19)
νC32-H34 (50) + νC46-H48 (28)+νC33-H36(15)
νC32-H34 (12) + νC46-H48 (39)+νC33-H36(10)+νC35-H37(16)+νC47-H49(23)
νC50-H52 (79) +νC51-H53 (15)
3018
11.56
2.29
νC39-H41 (95)
a
Scale factor: 0.9608-B3LYP/6-31G(d, p),
: Stretching; β – in-plane bending: Γ – out-of-plane bending: PED: Potential energy distribution
b
ν

1
Table 2. H Chemical shift values of compounds 3 and 4
3
4
Atom
Expt.
6.12
5.48
DFT
6.43
5.79
Expt.
5.98
4.92
DFT
6.01
5.05
H1
H5
H2A
H2B
H4
2.68
3.13
2.88
2.82
3.45
2.91
2.94
3.16
3.16
3.01
3.41
3.35
ArC-H
NCOCH Cl
7.06-7.30
3.92
7.14-7.42
4.12
6.45-7.27
4.21
6.71-7.51
4.78
-
2
-
-
CH2-
CH3
1.25-1.68
0.90
1.31-1.81
0.99
1.25-1.71
0.88
1.41-1.98
0.92

13
Table 3. C Chemical shift values of compounds 3 and 4
3
4
Atom
Expt.
209.17
169.26
DFT
212.31
171.51
Expt.
207.83
168.03
DFT
210.41
170.28
C3
C12
Ar-C
C5
C1
C4
126.01-129.31 129.02-131.40 127.77-143.84 129.74-145.08
59.04
56.86
50.60
47.12
42.53
61.21
57.71
50.81
48.21
42.71
22.78
30.14
32.74
13.98
62.35
58.38
53.01
46.78
42.60
22.41
29.23
30.29
13.83
62.53
58.80
53.30
46.97
42.96
22.94
29.39
30.42
14.01
C2
-
NCOCH Cl
2
2
2.22
29.23
2.28
13.80
-
CH2-
CH3
3
-

Table 4 Crystal data and structure refinement details of compound 3
CCDC Number
Empirical formula
Formula weight
Temperature
CCDC 1502783
C H ClNO
2
23
26
383.90
292 (2) K
0.71073 Å
Monoclinic
Wavelength
Crystal system
Space group
P2 /c
1
a = 21.2136(15) Å; α = 90°.
Unit cell dimensions
b = 8.7450(6) Å; β = 112.1120(10)°.
c = 23.9627(16) Å; γ = 90°.
3
Volume
4118.4(5) Å
Z
8
3
Density (calculated)
Absorption coefficient
F(000)
1.238 Mg/m
-1
0.203 mm
1632
Theta range for data collection
Index ranges
2.4 to 28.4°.
-28 ≤ h ≤ 28, -11 ≤ k ≤ 11, -31 ≤ l ≤ 31
46797
Reflections collected
Independent reflections
Completeness to theta = 25.242°
Refinement method
10023 [R(int) = 0.0231]
99.9 %
2
Full-matrix least-squares on F
Data / restraints / parameters
10023 / 2 / 487
1.041
2
Goodness-of-fit on F
Final R indices [I>2sigma(I)]
R indices (all data)
R = 0.073, wR = 0.212
1
2
R = 0.097, wR = 0.240
1
2
-3
Largest diff. peak and hole
0.920 and -0.457 e.Å

Table 5 Bond lengths (Ǻ), bond angles (°) for non-H atoms with esd’s in parenthesis
Atom
Cl(1)-C(13)
O(1)-C(3)
O(2)-C(12)
N(1)-C(12)
N(1)-C(5)
N(1)-C(1)
C(1)-C(6)
C(1)-C(2)
C(2)-C(3)
Bond length
1.766(2)
1.204(3)
1.226(3)
1.359(3)
1.486(3)
1.487(3)
1.522(3)
1.536(3)
1.492(3)
1.513(3)
1.540(3)
1.547(3)
1.530(3)
1.377(3)
1.486(4)
1.479(6)
1.404(6)
1.765(2)
1.358(3)
1.481(3)
1.493(2)
1.206(3)
1.223(3)
1.521(3)
1.539(3)
1.497(3)
1.511(3)
1.533(3)
1.559(3)
1.523(3)
1.502(4)
1.601(5)
1.393(7)
Atom
Bond angle
122.4(2)
121.8(2)
115.8(2)
111.9(2)
107.5(2)
112.3(2)
111.7(2)
109.3(2)
116.6(2)
118.7(2)
122.6(2)
122.7(2)
120.8(2)
116.4(2)
111.8(2)
115.9(3)
114.4(4)
119.8(6)
117.3(2)
122.1(2)
119.1(2)
113.8(2)
110.7(2)
108.0(2)
115.2(2)
121.8(2)
122.7(2)
115.5(2)
111.7(2)
109.0(2)
110.3(2)
112.2(2)
108.9(2)
117.1(2)
118.7(2)
118.9(2)
122.3(2)
122.7(2)
O(1)-C(3)-C(2)
O(1)-C(3) -C(4)
C(2)-C(3)-C(4)
C(3)-C(4)-C(5)
C(3)-C(4)-C(20)
C(5)-C(4)-C(20)
N(1)-C(5)-C(14)
N(1)-C(5)-C(4)
C(14)-C(5)-C(4)
C(11)-C(6)-C(7)
C(11)-C(6)-C(1)
O(2)-C(12)-N(1)
O(2)-C(12)-C(13)
N(1)-C(12)-C(13)
C(12)-C(13)-Cl(1)
C(21)-C(20)-C(4)
C(22)-C(21)-C(20)
C(23)-C(22)-C(21)
C(12')-N(1')-C(5')
C(12')-N(1')-C(1')
C(5')-N(1')-C(1')
N(1')-C(1')-C(6')
N(1')-C(1')-C(2')
C(6')-C(1')-C(2')
C(3')-C(2')-C(1')
O(1')-C(3')-C(2')
O(1')-C(3')-C(4')
C(2')-C(3')-C(4')
C(3')-C(4')-C(5')
C(3')-C(4')-C(20')
C(5')-C(4')-C(20')
N(1')-C(5')-C(14')
N(1')-C(5')-C(4')
C(3)-C(4)
C(4)-C(5)
C(4)-C(20)
C(5)-C(14)
C(6)-C(11)
C(20)-C(21)
C(21)-C(22)
C(22)-C(23)
Cl(1')-C(13')
N(1')-C(12')
N(1')-C(5')
N(1')-C(1')
O(1')-C(3')
O(2')-C(12')
C(1')-C(6')
C(1')-C(2')
C(2')-C(3')
C(3')-C(4')
C(4')-C(5')
C(4')-C(20')
C(5')-C(14')
C(20')-C(21')
C(21')-C(22')
C(22')-C(23')
Atoms
Bond angle C(14')-C(5')-C(4')
C(12)-N(1)-C(5)
C(12)-N(1)-C(1)
C(5)-N(1)-C(1)
N(1)-C(1)-C(6)
117.3(2)
121.8(2)
119.4(2)
113.8(2)
C(7')-C(6')-C(11')
C(7')-C(6')-C(1')
C(11')-C(6')-C(1')
O(2')-C(12')-N(1')

N(1)-C(1)-C(2)
C(6)-C(1)-C(2)
C(3)-C(2)-C(1)
110.5(2)
108.2(2)
114.6(2)
O(2')-C(12')-C(13')
N(1')-C(12')-C(13')
C(12')-C(13')-Cl(1')
C(19')-C(14')-C(15')
120.9(2)
116.4(2)
111.7(2)
117.7(2)

Table 6 Second order perturbation interactions from NBO calculations of compounds 3 and 4.
3
4
Type Donor (i) ED/e Acceptor(j) ED/e
Ej-Ei
a.u)
1.2
0.94
1.03
1.3
0.9
1.3
0.47
1.3
Fi,j
(a.u)
Ej-Ei
Fi,j
(a.u)
0.045
0.047
0.021
0.03
2
2
E (kJ/mol)
E (kJ/mol)
(
(a.u)
1.18
0.95
1.01
1.28
0.89
1.3
σ
σ
σ
σ
σ
σ
π
σ
-
-
-
-
-
-
-
-
σ
σ
σ
σ
σ
σ
*
*
*
*
*
C1-C2
C1-H1
C4-C5
C5-H5
C4-H4
1.97
1.97
1.97
1.96
1.96
C3-O1
C2-H2
C3-O1
C1-N1
C4-C5
C5-N1
C13-Cl1
C5-N1
0.01
0.01
0.01
0.05
0.03
0.04
0.03
0.05
9.46
11.34
11.97
15.98
12.22
9.33
0.047
0.045
0.024
0.032
0.04
0.032
0.035
0.032
8.58
8.79
10.92
16.32
8.95
8.95
12.64
13.77
0.04
* C12-O12 1.99
0.032
0.034
0.032
σ*
1.98
* C12-C13 1.99
C12-
13.89
13.43
0.47
1.3
σ
σ
σ
-
-
σ*
1.99
N1-C5
0.07
0.01
22.51
6.28
1
0.066
0.028
22.34
6.40
1
0.066
0.028
H13A
C13-
H13B
σ*
1.98
C12-O2
1.23
1.23
σ
-
π
π
σ
σ
σ
π
σ
σ
σ
σ
σ
*
C12-O2
C12-O2
C1-H1
C4-C5
C4-H4
C12-O2
C3-C4
C2-C3
N1-C12
C12-C13
C13-Cl1
0.29
0.29
0.02
0.03
0.02
0.29
0.07
0.06
0.07
0.07
0.03
13.56
8.41
14.94
18.28
2.38
255.60
72.01
86.23
88.07
87.28
3.68
0.67
0.67
1.18
0.98
1.08
0.67
1.46
1.48
1
0.028
0.028
0.033
0.026
0.026
0.028
0.031
0.03
13.31
9.46
13.26
19.46
2.18
251.00
70.42
86.78
87.82
67.78
3.26
0.66
0.66
1.18
0.98
1.08
0.66
1.46
1.48
1
0.027
0.027
0.033
0.026
0.026
0.027
0.031
0.03
σ-
* C13-Cl1 1.99
* LP(1)N1 2.00
*
*
n-
n-
n-
n-
n-
n-
n-
n-
n-
*
* LP(2)O1 1.89
*
* LP(2)O2 1.86
*
*
0.066
0.031
0.035
0.066
0.031
0.035
1.39
0.47
1.39
0.47