Synthesis, analysis of spectroscopic and nonlinear optical properties of the novel compound: (S)-N-benzyl-1-phenyl-5-(thiophen-3-yl)-4-pentyn-2-amine

Article abstract of DOI:10.1016/j.saa.2012.05.087

In this study, a novel compound (S)-N-benzyl-1-phenyl-5-(thiophen-3-yl)-4- pentyn-2-amine (abbreviated as BPTPA) was synthesized and structurally characterized by FT-IR, NMR and UV spectroscopy. The molecular geometry and vibrational frequencies of BPTPA

Full text of DOI:10.1016/j.saa.2012.05.087

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
Contents lists available at SciVerse ScienceDirect
Spectrochimica Acta Part A: Molecular and
Biomolecular Spectroscopy
journal homepage: www.elsevier.com/locate/saa
Synthesis, analysis of spectroscopic and nonlinear optical properties of the
novel compound: (S)-N-benzyl-1-phenyl-5-(thiophen-3-yl)-4-pentyn-2-amine
b
b
c
c
b
Mehmet Karabacak a, , Caglar Karaca , Ahmet Atac , Mustafa Eskici , Abdullah Karanfil , Etem Kose
⇑
a Department of Physics, Afyon Kocatepe University, Afyonkarahisar, Turkey
b Department of Physics, Celal Bayar University, Manisa, Turkey
c Department of Chemistry, Celal Bayar University, Manisa, Turkey
g r a p h i c a l a b s t r a c t
h i g h l i g h t s
"
Spectroscopic properties of the novel
molecule were examined by FT-IR,
NMR and UV techniques and DFT.
The complete assignments were
performed on the basis of the total
energy distribution (TED).
"
"
"
Nonlinear optical properties of the
molecule were studied.
HOMO and LUMO energies,
molecular electrostatic potential
distribution of the molecule were
calculated.
a r t i c l e i n f o
a b s t r a c t
Article history:
In this study, a novel compound (S)-N-benzyl-1-phenyl-5-(thiophen-3-yl)-4-pentyn-2-amine (abbrevi-
ated as BPTPA) was synthesized and structurally characterized by FT-IR, NMR and UV spectroscopy. The
molecular geometry and vibrational frequencies of BPTPA in the ground state have been calculated by
using the density functional method (B3LYP) invoking 6-311++G(d,p) basis set. The geometry of the mol-
ecule was fully optimized, vibrational spectra were calculated. The fundamental vibrations were assigned
on the basis of the total energy distribution (TED) of the vibrational modes, calculated with scaled quan-
tum mechanics (SQM) method and PQS program. Total and partial density of state (TDOS and PDOS) and
also overlap population density of state (OPDOS) diagrams analysis were given. The energy and oscillator
strength of each excitation were calculated by time-dependent density functional theory (TD-DFT) results
complements with the experimental findings. The NMR chemical shifts (1H and 13C) were recorded and
calculated using the gauge invariant atomic orbital (GIAO) method. The dipole moment, linear polarizabil-
ity and first hyperpolarizability values were also computed. The linear polarizability and first hyper polar-
izability of the studied molecule indicate that the compound is a good candidate of nonlinear optical
materials. Finally, vibrational wavenumbers, absorption wavelengths and chemical shifts were compared
with calculated values, and found to be in good agreement with experimental results.
Received 22 March 2012
Received in revised form 10 May 2012
Accepted 20 May 2012
Available online 7 July 2012
Keywords:
(S)-N-benzyl-1-phenyl-5-(thiophen-3-yl)-4-
pentyn-2-amine
FT-IR, 13C, 1H NMR and UV spectra
DFT
HOMO–LUMO
Nonlinear optical properties
Ó 2012 Elsevier B.V. All rights reserved.
Introduction
tries [2], in conducting polymer design [3], as well as in nonlinear
optical materials [4]. Thiophene derivatives are also often used as
Thiophene-containing compounds are known as materials with
potential applications in the flavor [1] and pharmaceutical indus-
intermediates in a wide range of areas of synthetic chemistry.
The insertion of thiophene in the linear ethynyl–phenyl conjugated
chain, gives a higher electron delocalization to the molecule [5]. In
general, the conjugated molecules, integrating the thiophene rings
and the end-capped N,N-dimethyl-amino-phenyl moiety, of
⇑
Corresponding author. Tel.: +90 272 2281311; fax: +90 272 2281235.
E-mail address: karabacak@aku.edu.tr (M. Karabacak).
1386-1425/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.saa.2012.05.087

M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
557
precise length and constitution, exhibit high thermal stability [6,7]
and show intrinsic electronic properties such as: luminescence [8],
redox [9] and charge transport [10].
before use. 3-Ethynylthiophene (96%) was purchased from Aldrich
Chemical Company (USA) and used as received. (S)-3,4-dibenzyl-
1,2,3-oxathiazlodine-2-2-dioxide was prepared according to the
literature procedure [27].
The structure of thiophene was thoroughly studied theoreti-
cally, as well as, experimentally in gas phase, liquid and solid phase
[11–16]. It was studied in 1965 by Rico et al. [17] and the assign-
ments of fundamental modes were proposed. Klots et al. [14] made
a detailed vibrational analysis of thiophene in vapor phase and ob-
tained a complete set of vibrational wavenumbers of the funda-
mental modes. Vibrational analysis of thiophene and its solvation
in two polar solvents (DMSO and methanol) by Raman spectros-
copy combined with ab initio and DFT calculations were studied
by Singh et al. [15].
DFT has emerged as a powerful tool in studying vibrational
spectra of fairly large molecules. The DFT calculations are reported
to provide excellent vibrational frequencies of organic compounds
if the calculated frequencies are scaled to compensate for the
approximate treatment of electron correlation, for basis set defi-
ciencies and for the anharmonicity [16–19]. GIAO/DFT approach
is widely used for the calculations of chemical shifts for a variety
of heterocyclic compounds [20–22]. Therefore, we have utilized
the gradient corrected DFT [23] with the Becke’s three-parameter
hybrid functional (B3) [24] for the exchange part and the Lee–
Yang–Parr (LYP) correlation function [25], accepted as a cost-effec-
tive approach, for the computation of molecular structure, vibra-
tional frequencies and energies of optimized structures.
As a part of the research aimed at investigation of the reactivity
of cyclic sulfamidates towards acetylides, (S)-N-benzyl-1-phenyl-
5-(thiophen-3-yl)-4-pentyn-2-amine is synthesized using the
reaction of phenylalanine-derived 1,2-cyclic sulfamidate with the
acetylide prepared from 3-ethynylthiophene [26] and structurally
characterized FT-IR, NMR and UV spectroscopy. A comprehensive
theoretical structurally characterization of the title compound
including FT-IR, NMR and UV calculations by using the density
functional method (B3LYP) invoking 6-311++G(d,p) basis set is pre-
sented in this study. The results of theoretical characterization
were compared with experimental characterization data. Besides
these, the dipole moment, nonlinear optical (NLO) properties, lin-
ear polarizability and first hyperpolarizability, chemical hardness
and Mulliken atomic charge were also studied using the same
method and basis set. As a result, vibrational wavenumbers,
absorption wavelengths and chemical shifts values are in fairly
good agreement with the experimental results.
Synthesis of N-benzyl-1-phenyl-5-(thiophen-3-yl)-4-pentyn-2-amine
To
a
stirred solution of 3-ethynylthiophene (503 mg,
4.46 mmol) in 15 mL freshly distilled dry THF containing 1.5 mL
HMPA cooled at ꢀ10 °C (ice-salt) under argon atmosphere was
added drop wise n-butyl lithium (2.9 mL, 4.62 mmol, 15% solution
in n-hexane). After stirring at ꢀ10 °C for 1 h, a solution of (4S)-3,4-
dibenzyl [1–3]oxathiazolidine-2,2-dioxide (705 mg, 2.32 mmol) in
3 mL dry THF was added to the resulting acetylide solution via a
syringe and stirring continued for additional 2 h. The reaction mix-
ture was allowed to warm up to room temperature and then trea-
ted with 5 M 3 mL HCl solution to hydrolze the N-sulfate
intermediate for 2 h before neutralization with saturated NaHCO3
solution. Extraction with ether three times and drying over anhy-
drous Na2SO4 followed by evaporation of volatiles in vacuo gave
the crude product. Purification by column chromatography using
a (EtOAc: hexane (1:10) to (1:6) gradient) solvent system contain-
ing 0.5% triethylamine afforded (S)-N-benzyl-1-phenyl-5-(2-thio-
phen-3-yl)-pent-4-yn-2-amine as a pale yellow oil (720 mg, 94%
yield). Partial decomposition of the product on silica was also ob-
served. Rf: 0.59 [(EtOAc:Hexane) 1:3]; [
a]
31 + 8.4 (c = 1, CHCl3);
D
IR (film);
t
max/cmꢀ1 3328 (NH), 2228 (C„C), 1602, 1584, 1520,
1462 (aromatic C„C), dH (400, MHz, CDCl3) (ppm) 2.48 (1H, dd,
J = 5.6 and 17), 2.54 (1H, dd, J = 5.6 and 17), 2.85–2.93 (2H, m),
3.04 (1H, quintet, J = 5.6), 3.81 (1H, d, J = 13.2), 3.89 (1H, d,
J = 13.2), 7.08 (1H, dd, J = 1.2 and 4.8, ArAH), 7.19–7.30 (11H, m,
ArAH), 7.35 (1H, dd, J = 0.8 and 2.8, ArAH); dC (100 MHz, CDCl3)
(ppm) 24.39, 40.78, 51.42, 57.52, 78.23, 86.92, 122.96, 125.34,
126.58, 127.16, 128.17, 128.29, 128.64, 128.70, 129.65, 130.27,
139.19, 140.62; HRMS (CI): [M+H]+ found 332.1472, C22H21NS re-
quires 332.1473 (Scheme 1).
FT-IR, NMR and UV measurements
The FT-IR spectrum of BPTPA was recorded in the region 600–
4000 cmꢀ1 on a Perkin-Elmer FT-IR System Spectrum BX spectrom-
eter which was calibrated using polystyrene bands. The ultraviolet
absorption spectrum of BPTPA, solved in water, ethanol and chlo-
roform, was examined in the range 200–400 nm using Shimadzu
UV-1700 PC, UV–vis recording Spectrophotometer. NMR chemical
shifts were recorded in Varian Infinity Plus spectrometer at
300 K. The compound was dissolved in chloroform. Chemical shifts
were reported in ppm relative to tetramethylsilane (TMS) for 1H
and 13C NMR spectra. The 1H, 13C and APT NMR spectra were used
for the full characterization of the compound.
Experimental
Materials
Hexamethylphosphoramide (HMPA) was distilled from sodium
metal and tetrahydrofuran (THF) was freshly distilled from LiAlH4
Scheme 1. Synthesis of (S)-N-benzyl-1-phenyl-5-(thiophen-3-yl)-4-pentyn-2-amine.

558
M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
Table 1
Computational details
The optimized geometry (bond lengths (Å) and bond angles (°)) of BPTPA.
The computational work aim to determine the optimize geometry
of the novel compound. The entire calculations were performed at
DFT/B3LYP [24,25] with the 6-311++G(d,p) basis set levels on a per-
sonal computer using Gaussian 09 [28] program package, invoking
gradient geometry optimization [29]. Optimized structural parame-
ters, vibrational frequency, isotropic chemical shift, electronic and
nonlinear optical properties were calculated. The vibrational fre-
quencies were calculated with this method, and wavenumbers in
the ranges from 4000 to 1700 cmꢀ1 and lower than 1700 cmꢀ1 were
scaled with 0.958 and 0.983, respectively, in order to improve the
agreement with the experimental results [30]. The theoretical results
have enabled us to make the detailed assignments of the experimen-
tal FT-IR spectra of the title molecule. The TED was calculated by
using the SQM method and PQS program [31]. The fundamental
Bond lengths
X-raya,b,c
B3LYP
Bond angles
X-raya,b,c
117a
B3LYP
C1AC2
C1AC6
C1AH19
C2AC3
C2AH20
C3AC4
C3AH21
C4AC5
C4AC7
1.39a
1.40a
1.393
1.395
1.084
1.396
1.085
1.400
1.086
1.402
1.513
1.392
1.086
1.085
1.542
1.093
1.095
1.551
1.464
1.103
1.459
1.096
1.095
1.206
1.467
1.016
1.514
1.096
1.103
1.397
1.400
1.396
1.086
1.392
1.085
1.396
1.084
1.392
1.085
1.084
1.439
1.377
1.422
1.362
1.081
1.726
1.079
1.735
1.079
120.64
119.12
120.24
111.7
124.0
124.3
113.0
123.0
124.0
112.1
127.5
120.5
111.7
128.4
119.9
91.6
C2AC1AC6
C2AC1AH19
C6AC1AH19
C1AC2AC3
C1AC2AH20
C3AC2AH20
C2AC3AC4
C2AC3AH21
C4AC3AH21
C3AC4AC5
C3AC4AC7
C5AC4AC7
C4AC5AC6
C4AC5AH22
C6AC5AH22
C1AC6AC5
C1AC6AH23
C5AC6AH23
C4AC7AC8
C4AC7AH24
C4AC7AH25
C8AC7AH24
C8AC7AH25
119.5
120.3
120.2
120.1
120.1
119.8
121.0
119.6
119.4
118.2
121.4
120.4
120.9
119.4
119.6
120.2
120.0
119.8
113.9
109.6
109.9
107.8
108.2
107.2
110.4
109.9
108.1
109.6
107.6
111.2
113.7
108.4
109.2
110.2
108.8
106.2
115.1
109.3
108.3
111.6
108.4
112.2
108.9
109.2
106.3
120.7
120.6
118.6
120.8
119.5
119.7
120.0
119.8
120.1
119.6
120.2
120.2
120.2
120.0
119.8
1.40a
1.40a
120a
123a
1.41a
1.50a
1.4a
C5AC6
117a
124a
118a
120a
C5AH22
C6AH23
C7AC8
C7AH24
C7AH25
C8AC9
C8AN11
C8AH26
C9AC10
C9AH27
C9AH28
1.54a
1.54a
1.46a
122a
110a
vibrational modes were characterized by their TED. The 1H and 13
C
NMR chemical shifts (dH and dC) of the compound were calculated
using the GIAO method [32] in chloroform. The electronic properties
were also calculated using B3LYP method of the time-dependent DFT
(TD-DFT) [33–35], basing on the optimized structure. TD-DFT has
been proved to be a powerful and effective computational tool for
the study of the ground and excited state properties by comparison
to the available experimental data. Hence, we used TD-DFT to obtain
wavelengths and compared the calculated results with the experi-
mental UV absorption values. Moreover, the dipole moment, nonlin-
ear optical (NLO) properties, linear polarizabilities and first
hyperpolarizabilities, chemical hardness and Mulliken atomic
charge were also been studied using B3LYP/6-311++G(d,p).
C10AC45
1.202c
1.461b
N
N
11AC12
11AH29
H
24AC7AH25
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
12AC13
12AH30
12AH31
13AC14
13AC18
14AC15
14AH32
15AC16
15AH33
16AC17
16AH34
17AC18
17AH35
18AH36
37AC38
37AC39
37AC45
38AC40
38AH41
39AS42
39AH43
40AS42
40AH44
13AC18AC17
13AC18AH36
17AC18AH36
38AC37AC39
38AC37AC45
39AC37AC45
37AC38AC40
37AC38AH41
40AC38AH41
37AC39AS42
37AC39AH43
1.454b
C7AC8AC9
C7AC8AN11
C7AC8AH26
C9AC8AN11
C9AC8AH26
110a
118a
1.377b
1.398b
1.358b
110a
N11AC8AH26
C8AC9AC10
C8AC9AH27
C8AC9AH28
1.394b
1.371b
1.398b
C
C
10AC9AH27
10AC9AH28
Results and discussion
H27AC9AH28
C8AN11AC12
C8AN11AH29
115a
110a
Molecular geometry
1.421c
1.377c
1.422c
1.377c
C12AN11AH29
The optimized geometrical parameters of BPTPA, calculated by
DFT/B3LYP/6-311++G(d,p) were listed in Table 1, in accordance
with numbering scheme given in Fig. 1. In the present study, we
employed full geometry optimization for BPTPA without symmetry
constraint. The optimized structure can only be compared with
other similar systems for which the crystal structures have been
solved [36–38]. The geometry of the molecule are determined be-
long to a true minimum proven by all real wavenumbers in the
vibrational analysis as seen from the Table 2. The optimized bond
lengths of CAC in the phenyl ring fall in the range from 1.392 to
1.402 Å for B3LYP/6-311++G(d,p) which are in good agreement
with those of structurally similar systems whose crystal structures
are elucidated (1.371–1.402 Å) [36–38]. The optimized CAN bond
lengths were calculated between 1.464 and 1.467 Å, show good
coherent with the observed as 1.46 Å for a similar structure [36].
These values showed more consistency with our calculation results.
The bond length S42–C39 was predicted at 1.726 Å (DFT), observed
as 1.727 Å [36]. However, particularly the XAH bond lengths are
predicted systematically too long from DFT method [39,40]. This
theoretical pattern also is found for BPTPA, since the large deviation
from experimental XAH bond lengths may arise from the low scat-
tering of hydrogen atoms in the X-ray diffraction experiment.
The bond angles of BPTPA were given in Table 1 are good agree-
ment with similar structures. For example, the bond angels of the
CACAC of the phenyl rings were observed between 117° and 123°
[36–38] and calculated 119.5–121.0°. The calculated bond angles
are better than experimental results according to the expected nor-
mal values 120°. Based on above comparison, although there are
some differences between the theoretical and experimental values,
the optimized structural parameters can well reproduce the exper-
imental one.
N
N
N
11AC12AC13
11AC12AH30
11AC12AH31
C
C
13AC12AH30
13AC12AH31
1.727c
1.730c
120b
H30AC12AH31
C
C
C
C
C
C
C
C
C
C
C
C
C
C
C
12AC13AC14
12AC13AC18
14AC13AC18
13AC14AC15
13AC14AH32
15AC14AH32
14AC15AC16
14AC15AH33
16AC15AH33
15AC16AC17
15AC16AH34
17AC16AH34
16AC17AC18
16AC17AH35
18AC17AH35
121.3b
120.1b
121b
111.7c
121.95c
126.8c
113.1c
111.7c
111.2c
91.8c
S42AC39AH43
C
C
38AC40AS42
38AC40AH44
S42AC40AH44
C39AS42AC40
a
b
c
Ref. [36].
Ref. [37].
Ref. [38].
Vibrational analysis
The vibrational frequencies were obtained using DFT/B3LYP
methods using split valence basis sets along with diffuse and polar-
ization function with 6-311++G(d,p) basis set. The selected calcu-

M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
559
The title molecule is non-planar and belongs to C1 point group
symmetry has no relevant distribution of species.
It is stated that the NAH stretching vibrations occur in the re-
gion 3300–3500 cmꢀ1 [41]. In this study, we predicted
3363 cmꢀ1
(m129), assigned to NAH stretching vibration, recorded
at 3328 cmꢀ1 in the FT-IR spectrum. This mode is a pure mode as is
evident from TED column contributing exactly 100%.
The CAN stretching mode is a rather difficult task since there
are problems in identifying these frequencies from other vibra-
tions. Silverstein [42] assigned CAN stretching absorption in the
region 1386–1266 cmꢀ1 for aromatic amines. This mode is ob-
served at 1293 cmꢀ1 by Bellamy et al. [43]. In this study, the
CAN stretching vibration is observed at 1180 cmꢀ1 and the com-
puted values are predicted at 1105 and 1115 cmꢀ1 (modes
and 72). There is a discrepancy which, may be due to mixing with
m71
m
CAC vibration. One can see TED value contributing to 25% and 77%
as shown Table 2.
Fig. 1. The theoretical optimized geometric structure and atoms numbering of
The hetero-aromatic structure shows the presence of CAH
stretching vibration in the region 3100–3000 cmꢀ1, which is the
characteristic region for the ready identification of CꢀH stretching
vibration [42,44,45]. The CAH stretching vibrations were calcu-
lated at 3021–3055 cmꢀ1 showed very good coherent with the
experimental data. For example the experimental value is assigned
at 3026 cmꢀ1, the calculated one is obtained at 3021 cmꢀ1. These
modes are pure stretching modes as seen from the TED column
shown in Table 2. The in-plane CAH bending vibrations appear in
BPTPA.
lated wavenumbers are given in Table 2. The experimental fre-
quencies given in the same table, is based on the FT-IR spectra of
BPTPA shown Fig. 2. The all calculated wavenumbers are given in
Supplementary material (Table S1). The vibrational analysis of
BPTPA is performed on the basis of the characteristic vibration
modes of C„C, CAC, NH, CH and CH2 groups of the compound.
Table 2
Comparison of the selected calculated harmonic frequencies and experimental (FT-IR) wavenumbers (cmꢀ1) using by B3LYP methods 6-311++G(d,p) of BPTPA.
Modes No.
Exp.
Theoretical
TEDb (P10%)
FT-IR
Unscaled freq.
Scaled freq.a
IInfrared
m34
m38
m41
m43
m50
626
696
746
780
858
636
710
758
785
862
626
698
745
772
848
0.53
32.19
37.51
37.04
1.82
dCCC(58) ring + dCCH(20) ring
s
s
CCCH(49)ring +
CCCH(39)ring +
s
s
CCCC(38)ring
CCCC(14)ring
c
m
CH(89) thio
CC(36)
m53
m54
m55
m58
m62
m64
m65
m68
m72
m76
m79
m81
m82
m84
m85
m91
m94
m95
m97
m98
m100
m103
m104
m105
m108
m111
m114
m116
m125
m126
m127
m129
894
910
928
976
907
924
945
991
892
909
929
974
6.10
0.78
0.86
3.13
0.57
12.10
5.17
3.99
49.41
1.54
1.05
11.94
0.10
13.47
0.39
21.83
7.83
11.2
6.06
8.24
57.91
3.89
dCCC(21)thio + dCCS(14)thio + dSCH(12)thio + mC10C9(12)
c
c
CH(76) ring
CH(74) ring
rCH2(29) +
s
CHCH(15) ring
CC(37) ring + dCCC(37) ring {trigonal ring breathing}
CC(33) + CC(17) thio
1004
1014
1028
1078
1118
1180
1202
1218
1232
1278
1300
1358
1428
1454
1462
1470
1493
1520
1584
1602
2228
2847
2920
3026
3062
3084
3106
3328
1017
1031
1047
1095
1135
1200
1223
1246
1253
1306
1329
1378
1451
1470
1482
1489
1513
1563
1622
1623
2326
3025
3060
3153
3189
3212
3247
3510
1000
1014
1029
1077
1115
1179
1202
1225
1232
1284
1306
1354
1426
1445
1457
1464
1487
1537
1594
1596
2228
2898
2932
3021
3055
3077
3110
3363
m
m
m
m
m
m
m
m
CC(25) ring + dCCH(15) ring +
CC(25) ring + dCCH(18) ring
CN(77)
CC(17) ring + dCCH(76) ring
C12ACring(39) + mCC(19) ring + dCCH(10) ring
mC8C7(14)
tCH2(46)
tCH2(40)
x
x
x
CH2(50) + dCCH(11)
CH2(52) + dCCH(10)
CH2(22) + d CH26(18) +
m CC(10) thio.
m
CC(80) thio + dCCH (10) thio
CH2(94)
dCCH(46) ring +
q
mCC(28) ring
qCH2(69)
qCH2(53) + d CNH(34)
m
m
m
m
m
m
m
m
m
m
m
C = Cthio(57) + d CCH(14) thio. +
CC(69) ring + dCCH(12) ring
CC(70) ring + dCCH(12) ring
C„C(100)
symCH2(97)
asymCH2(98)
CH(100) ring
CH(97) ring
CH(100) thio.
CH(99) thio.
m C37C45(10) + dCCC(10) thio.
0.84
0.84
2.68
23.46
15.26
8.25
12.52
9.02
4.89
8.73
NH(100)
a
Wavenumbers in the ranges from 4000 to 1700 cmꢀ1 and lower than 1700 cmꢀ1 are scaled with 0.958 and 0.983 for B3LYP/6-311++G(d,p) basis set, respectively.
TED, total energy distribution; m, stretching; d, in-plane bending, c, out-of-plane bending; q, scissoring, x, wagging; s, torsion; r, rocking; t, twisting.
b

560
M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
variable intensity and are observed at 1625–1590, 1575–1590,
1470–1540, 1430–1465 and 1280–1380 cmꢀ1 from the frequency
ranges given by Varsanyi [45]. In the present work, the frequencies
computed at 1029–1086, 1308–1317 and 1594–1616 cmꢀ1 (see
Table 2) were assigned as CC stretching vibrations according to
TED. The TED contribution for these modes are mixed with combi-
nation of CAH in plane bending. The CC stretching vibrations were
assigned at 1028, 1078, 1584 and 1602 cmꢀ1 in the FT-IR spectrum.
The CCC in plane deformation vibrations are observed higher
wavenumbers than the CCC out of plane vibrations. The theoreti-
cally calculated in-plane and out-of plane vibrations show good
agreement with recorded spectral data.
The ring breathing vibrations are observed in the region 1100–
1000 cmꢀ1. As revealed by TED, the ring-breathing modes of the
aromatic rings were calculated at 999 and 1000 cmꢀ1. In FT-IR
spectrum, the ring breathing vibration was observed at
1004 cmꢀ1. The ring assignments proposed in this study are also
in agreement with the literature values [22,30,40,42].
The CAC stretching modes were observed at 1516 cmꢀ1 mode
for 3-ethꢀy1nylthiophene [49]. This peak was observed at 1428 and
Fig. 2. The observed and calculated Infrared spectra of BPTPA.
1520 cm
in FT-IR spectrum and calculated at 1426 and
1537 cmꢀ1
.
the range 1000–1300 cmꢀ1 and the CAH out of plane bending
vibrations occur in the frequency range 750–1000 cmꢀ1. In this
study, the CAH in plane and out-of-plane bending vibrations are
also lie within the characteristic region. For example, the CAH
in-plane bending vibrations are observed at 1078 and 1180 cmꢀ1
in FT-IR. The calculated frequencies are 1077 and 1179 cmꢀ1 that
are well correlated with the experimental frequencies. The CAH
out of plane bending vibrations are predicted in the region 986–
843 cmꢀ1. The observed frequencies (910 and 928 cmꢀ1) are coin-
The C„C modes, its position is highly characteristic, arise from
conjugation and from aromatic substitutions are also very informa-
tive. The C„C mode of the compound was calculated and observed
the same value, at 2228 cmꢀ1. It is evident of TED value contribut-
ing to 100%. Also this mode is very good agreement with the liter-
ature [50].
Identification of CAS stretching vibration is difficult and also
uncertain. The recorded four peaks which are 608.8, 753.5, 839.5,
and 872.8 cmꢀ1 were assigned to CAS stretching by [14,15] accord-
ing to potential energy distribution (PED) obtained from DFT calcu-
lations. Coruh et al. [16] assigned this mode at 834 cmꢀ1 in FT-IR
spectrum. In this study, we have assigned three CAS stretching
modes, based on TED calculations; this mode recorded in FT-IR
spectra at 858 cmꢀ1. The CAS stretching modes are calculated at
641, 846 and 848 cmꢀ1 have dominant contribution assigned by
TED.
The remainder of the observed and calculated wavenumbers
and assignments of present molecule are shown in Table S1.
The correlation graphic which described harmony between the
calculated and experimental wavenumbers (Supp. Material
Fig. S1). As can be seen from Fig. S1, experimental fundamentals
have a good correlation with B3LYP. The relations between the cal-
culated and experimental wavenumbers are linear and described
by the following equation:
ciding very well with the calculated ones (909 and 929 cmꢀ1
respectively).
,
The CAH (for thiophene ring) stretching vibrations are calcu-
lated at 3077, 3110 and 3114 cmꢀ1 and observed at 3084 and
3106 cmꢀ1 in FT-IR. The CAH out of plane bending of the thiophene
ring were calculated at 675, 772 and 881 cmꢀ1 which show good
agreement with value at 780 cmꢀ1. According to TED, the CH in
plane bending modes of thiophene ring are predicted at 1086,
1185 and 1238 cmꢀ1 which have major contribution.
The CAH stretching of the methylene groups are at lower fre-
quencies than those of the aromatic CAH ring stretching. The
asymmetric stretching for the CH2, CH3, etc. has magnitude higher
than the symmetric stretching. The CH2 asymmetric stretching
vibrations are generally observed in the region 3000–2900 cmꢀ1
,
while the CH2 symmetric stretch will appear between 2900 and
2800 cmꢀ1 [42,45–47]. The scissoring mode of the CH2 group gives
rise to characteristic band near 1465 cmꢀ1 in IR spectrum [48]. In
this work, the CH2 asymmetric and symmetric stretching vibra-
tcal: ¼ 1:0015texp : ꢀ 2:7481
ðR2 ¼ 0:9999Þ
As a result, the scaled fundamental vibrational are in good consis-
tency with the experimental results and are found a good agree-
ment above the predicated literature.
tions were observed in FT-IR spectra at 2847 and 2920 cmꢀ1
,
respectively. The calculated symmetric CH2 stretching vibrations
of the methylene group were obtained at 2898, 2902 cmꢀ1and
the calculated asymmetric ones were obtained at 2932 and
2949 cmꢀ1. The CH2 scissoring vibrations were calculated at
1487, 1484, 1464 and 1445 cmꢀ1. The experimental values were
assigned at 1454, 1470 and 1493 cmꢀ1 which show excellent
agreement with calculated ones. The CH2 wagging vibrations were
assigned in FT-IR at 1358, 1300 and 1278 cmꢀ1 that were calcu-
lated 1354, 1306 and 1284 cmꢀ1 which have major contribution
according to TED. The CH2 twisting vibrations were observed in
FT-IR at 1218 and 1232 cmꢀ1 which show agreement with calcu-
lated values (1225 and 1232 cmꢀ1). The rocking mode was ob-
served at 976 cmꢀ1 in the infrared spectrum correlates well with
NMR spectra
Experimental 1H, 13C and APT NMR spectra were recorded as
shown in Figs. 3–5. The 13C and 1H theoretical chemical shifts
and the assignments of BPTPA are presented in Table 3, according
to the Fig. 1 atom positions. Firstly, full geometry optimization of
BPTPA was performed at the gradient corrected density functional
level of theory using the hybrid B3LYP method based on Becke’s
three parameters. Then, gauge- invariant atomic orbital (GIAO)
1H and 13C chemical shift calculations of the compound was done
by same method using 6-311++G(d,p) basis set IEFPCM/chloroform
solution. Application of the GIAO [51] approach to molecular sys-
tems was significantly improved by an efficient application of the
scaled value at 974 cmꢀ1
(m58).
The ring carbon–carbon stretching vibrations in benzene ring
occur in the region 1430–1625 cmꢀ1. In general, the bands are of

M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
561
method to the ab initio SCF calculation, using techniques borrowed
from analytic derivative methodologies. Relative chemical shifts
were estimated by using the corresponding TMS shielding calcu-
lated in advance at the same theoretical level as the reference.
The 1H and 13C NMR spectra were taken in chloroform by using
IEFPCM method [52].
In this study, there are twenty-two carbon signals calculated
theoretically of which are sixteen aromatic carbon signals. The
twelve aromatic carbon signals out of sixteen aromatic carbons
were only observed experimentally in the 13C spectrum of the mol-
ecule, due to the symmetry of two phenyl rings. In contrast to car-
bon signals, twenty-one proton signals were calculated while
twenty protons were observed in the 1H spectrum according to
integration. The proton which is calculated at 1.16 ppm (H29) is
not observed in the 1H spectrum. The chemical shifts of NH protons
in generally would be more susceptible to intermolecular interac-
tions as compared other heavier atoms. Therefore the NAH proton
signal varies greatly with concentration and solvent effects and
occasionally can’t be seen in the spectra [53].
In general, chemical shifts for the protons of organic molecules
vary greatly with the electronic environment of the proton. Hydro-
gen attached or nearby electron- withdrawing atom or group can
decrease the shielding and move the resonance of attached proton
towards to a higher frequency. By contrast electron-donating atom
or group increases the shielding and moves the resonance towards
to a lower frequency [54]. The chemical shifts of aromatic protons
of organic compounds are usually observed in the range of 7.00–
8.00 ppm, while aliphatic protons resonance in the high field. The
signals of the thirteen aromatic proton (1H) of the title compound
were calculated theoretically 7.13–7.96 ppm, observed at 7.08–
7.35 ppm experimentally. We predicted H36 at 7.96 ppm in the
lowest field, and H32 at 7.13 ppm in the highest field of the aro-
matic region. These protons are observed at 7.35 and 7.08 ppm,
respectively. Other eleven aromatic protons are accumulated in
the range of 7.33–7.69 ppm, observed experimentally at 7.19–
7.30 ppm. The protons resonance in this region could not be as-
signed unambiguously one by one due to overcrowding experi-
mentally. It is very interesting to note that despite the protons
(H32, H36) of the molecule are expected to be symmetrical, the pro-
ton (H32) facing to the other phenyl ring is to have experienced dif-
ferent magnetic environment than H36, as suggested by the
theoretical and experimental results, thereby leading to the obser-
vation of the proton (H32) at a reduced chemical shift compared to
the other one. The origin of this phenomenon could be somewhat
attributable to the molecular dynamics of this relatively complex
molecule.
The aliphatic seven protons were calculated in the region of
2.36–4.03 ppm, observed in 2.48–3.89 ppm. Benzylic protons were
predicted at 4.03 (H30) and 3.00 (H31) ppm, observed at 3.89 and
3.81 ppm, respectively. Methine proton (H26
) was calculated
2.94 ppm, observed as quintet at 3.04 ppm showing a good agree-
ment. Methylene protons (H24, H25) of the molecule were predicted
at 3.63 and 2.36 ppm and observed as multiplet in 2.85–2.93 ppm.
The methylene protons (H28, H27) next to the triple bond were cal-
culated at 3.21 and 2.36 ppm, respectively, while observed as two
different doublet of doublets at 2.54 and 2.48 ppm. Overall, the cal-
culated protons chemical shifts of the molecule show fairly good
correlation to the experimental spectrum.
Aromatic carbons give signals in overlapped areas of the spec-
trum with chemical shift values ranging from 100 to 150 ppm
[53,55]. The sixteen aromatic carbons were calculated in the region
of 126.57–148.11 ppm theoretically, observed signals are in the
range of 122.96–140.62 ppm. Aromatic carbon chemical shifts
(ipso-carbons C4, C13) were calculated at 148.11 and 147.83 ppm,
observed at 140.62 and 139.19 ppm. The lowest signal of the aro-
matic carbons atom C37 was predicted at 126.57 ppm and observed
122.96 ppm according to 13C and APT NMR spectrum. The other
phenyl and thiophene ring carbon chemical shifts (thirteen aro-
2.90
2.85
3.9
3.8
7.4 7.3 7.2 7.1
2.50
3.04 3.00
7.2
6.8
6.4
6.0
5.6
5.2
4.8
4.4
4.0
3.6
3.2
2.8
2.4
2.0
Fig. 3. The experimental 1H NMR spectra of BPTPA.

562
M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
155
140
125
110
95
85
75
65
55
45
35
25
15
Fig. 4. The experimental 13C NMR spectra of BPTPA.
Fig. 5. The experimental APT NMR spectra of BPTPA.
matic carbons) were observed in the range of 125.34–130.27 ppm
and calculated in the range of 130.54–140.42 ppm, showing a good
correlation as seen in Table 3. Aliphatic carbons were observed in
the region of 20–90 ppm. Triple bond carbons were resonanced
at 86.92 (C10) and 78.23 ppm (C45) and the chemical shifts of these
carbons were calculated at 93.91 and 80.23 ppm, respectively.

M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
563
Table 3
Experimental and theoretical 1H and 13C NMR isotropic chemical shifts (with respect to TMS) of BPTPA by DFT B3LYP method.
Atom
B3LYP
Exp.a
Atom
B3LYP
Exp.a
C13
C4
C39
C40
C38
C3
C6
C18
C2
148.11
147.83
140.42
135.88
134.71
134.34
134.24
134.17
133.42
133.24
133.05
132.93
132.68
131.42
130.54
126.57
93.91
139.19/140.62
140.62/139.19
125.34–130.27
125.34–130.27
125.34–130.27
125.34–130.27
125.34–130.27
125.34–130.27
125.34–130.27
125.34–130.27
125.34–130.27
125.34–130.27
125.34–130.27
125.34–130.27
125.34–130.27
122.96
C8
C12
C7
C9
H36
H22
67.74
56.12
44.57
26.54
7.96
7.69
7.56
7.33
7.13
4.03
3.63
3.21
3.00
2.94
2.36
2.36
1.16
57.52
51.42
40.78
24.39
7.35
7.19–7.30
7.19–7.30
7.19–7.30
7.08
3.89/3.81
2.85–2.93
2.48/2.54
3.89/3.81
3.04
H35,H23,H43
H19,H21,H41,H33,H44,H20,H34
H32
H30
H24
H28
H31
H26
H25
H27
H29
C5
C14
C17
C15
C16
C1
C37
C10
C45
2.85–2.93
2.48/2.54
–
86.92
78.23
80.23
a
/ sign mean: or and – sign mean: signal of range.
Table 4
The experimental and computed absorption wavelength k (nm), excitation energies E (eV), absorbance and oscillator strengths (f) of BPTPA using TD-DFT/6-311G++(d, p).
Experimental
B3LYP
k (nm)
Energy (eV)
k (nm)
Energy (eV)
Osc. strength (f)
Major contribution (P10%)
Water
277
287
4.482
4.326
Water
260
248
4.769
5.000
0.2833
0.0931
HOMO ? LUMO (91%)
HOMOꢀ1 ? LUMO (91%)
Ethanol
278
287
4.460
4.321
Ethanol
Chloroform
Gas
260
249
4.769
4.980
0.2886
0.0910
HOMO ? LUMO (91%)
HOMOꢀ1 ? LUMO (91%)
HOMO ? LUMO (92%)
HOMOꢀ1 ? LUMO (92%)
HOMO ? LUMO (92%)
HOMOꢀ6 ? LUMO (94%)
Chloroform
279
286
4.444
4.336
260
249
4.769
4.980
0.3055
0.0811
277
297
4.482
4.180
0.4056
0.0020
Methine and methylene carbons were calculated at 67.74 (C8),
56.12 (C12), 44.57 (C7) and 26.54 (C9) using by the B3LYP method
and observed at 57.52, 51.42, 40.78 and 24.39 ppm, respectively,
as evident from 13C and APT spectra.
ian curves of unit height and FWHM (Full Width at Half Maximum)
of 0.3 eV using Gausssum2.2 [58]. Because of the results from mul-
tiplying DOS by the overlap population, the COOP is similar to DOS.
The TDOS, PDOS and COOP spectra are plotted in Figs. 6–8, respec-
tively. The most important application of the DOS plot is to demon-
strate MO (molecule orbital) compositions and their contributions
Molecular electrostatic potential, electronic structure and UV spectra
The calculations of the electronic structures of the title com-
pound were carried out using TD-DFT calculations with the
B3LYP/6-311++G(d,p) method. Before the electronic calculations,
the molecule was optimized in ground state using the DFT method
with B3LYP functional. It is obvious that the use of TD-DFT calcula-
tions for prediction of the electronic absorption spectra is a reason-
able method. The theoretical and experimental maximum
absorption wavelengths, excitation energies, absorbance and oscil-
lator strengths are collected in Table 4.
The energies of the some molecular orbitals such as NH, CH2,
C„C, phenyl and thiophene groups were individually studied with
respect to the percentage contribution of the each species to the
total energy of the compound. The molecular orbital of phenyl
and thiophene rings contain significant contribution to the BPTPA.
Two phenyl rings have 100% contribution to the LUMO of the mol-
ecule, while significant contributions to the HOMO of the com-
pound comes from the thiophene (48%) and C„C groups (29%).
The TDOS, PDOS and OPDOS or COOP density of states [56,57],
in terms of Mulliken population analysis were calculated and cre-
ated by convoluting the molecular orbital information with Gauss-
Fig. 6. Calculated total electronic density of states for BPTPA.

564
M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
Fig. 7. Calculated partial electronic density of states for BPTPA.
and CH2 M C„C systems for the states in energy window from
ꢀ0.58 to 7.99 eV. One can see nonbonding states; C„C M thio-
phene, CH2 M phenyls and CH2 M C„C systems in the ranges of
ꢀ1.6 to 0.5, ꢀ1.92 to ꢀ0.47 and ꢀ0.27 to 1.08 eV, respectively.
The OPDOS or COOP diagrams also showed that the NH M CH2
and NH M Phenyls have significant bonding characters which are
of positive value. Their energy values were calculated in the range
of 2.31–3.10, 4.01–4.23 eV for the NH M CH2 and 1.1–2.29, 4.39–
6.84 and 7.74–7.79 eV for NH M Phenyls (bonding interactions).
HOMO and LUMO are the main orbital taking part in chemical
reaction. The HOMO energy characterizes the ability of electron
giving, and the LUMO accepting, and the gap between HOMO
and LUMO characterizes the molecular chemical stability [60].
The energy gap between HOMO and LUMO is a critical parameter
in determining molecular electrical transport properties due to
the measurement of electron conductivity. As seen Fig. 9, the
HOMO of the title compound presents a charge density localized
on the thiophene, C„C and CH groups and LUMO is characterized
by a charge distribution on the two phenyl rings. The energy value
of HOMO was computed at ꢀ0.298 and LUMO is ꢀ0.167 a.u, and
the energy gap was calculated 0.131 a.u. The energy gap between
HOMO and LUMO explains the chemical reactivity, optical polariz-
ability, kinetic stability and chemical softness–hardness of a mole-
cule. The chemical hardness is a good indicator of the chemical
stability. The molecules having a small energy gap are known as
soft and having a large energy gap are known as hard molecules.
The hard molecules are not more polarizable than the soft ones be-
Fig. 8. Overlap population DOS curves of BPTPA.
to chemical bonding through the OPDOS plots which are also re-
ferred in the literature as Crystal Orbital Overlap Population
(COOP) diagrams. The COOP shows the bonding, anti-bonding
and nonbonding interaction of the two orbitals, atoms or groups.
A positive value of the COOP indicates a bonding interaction, how-
ever negative value means an anti-bonding interaction and zero
value indicates nonbonding interactions [59]. The PDOS mainly
presents the composition of the fragment orbitals contributing to
the molecular orbitals as seen from Fig. 6. The PDOS of phenyl
and thiophene groups is of very similar nature of state as in the
TDOS of BPTPA because of the higher energies than the other
groups, in terms of the extent of the contribution to the energy
of the molecular orbitals. The OPDOS or COOP diagrams were pre-
sented in Fig. 7. It is readily seen in Fig. 7 that the interaction be-
tween C„C and thiophene (green line) system was seen as a
negative (anti-bonding interaction) as well as CH2 M benzenes
cause they need big energy to excitation [61]. The hardness (
g) va-
lue of a molecule is formulated by the following equation [62].
ðꢀeHOMO
þ
eLUMO
Þ
g
¼
2
where eHOMO and eLUMO are the energies of the HOMO and LUMO
orbitals. The value of energy gap between the HOMO and LUMO
is 3.55656 eV and the value of hardness is 1.77828 eV for the title
molecule. The chemical hardness value is a little bit smaller than
that of (E)-4-methoxy-2-[(p-tolylimino)methyl]phenol molecule
[61], which is a Schiff based compound (1.842 eV), that is a hard-
ness molecule.

M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
565
Fig. 9. The frontier and second frontier molecular orbitals of BPTPA.
Fig. 11. Molecular electrostatic potential surface (MEPs) with in HOMO and LUMO
of BPTPA.
gions in terms of color grading (Figs. 10 and 11) and is very useful
in research of molecular structure with its physiochemical prop-
erty relationship [63,64]. The different values of the electrostatic
potential at the surface are represented by different colors. Poten-
tial increases in the order red < orange < yellow < green < blue. The
color code of these maps is in the range between ꢀ0.08538 a.u.
(deepest red) to 0.08538 a.u. (deepest blue) in compound, where
blue indicates the strongest attraction and red indicates the stron-
gest repulsion. MEPs color scale is such d+ ? dꢀ in the direction
red ? blue. As can be seen from the MEP map of the title molecule,
while regions having the negative potential are over the electro-
negative atoms (C„C group and Nitrogen atom), the regions hav-
ing the positive potential are over the sulfur and hydrogen
atoms. The negative potential value is ꢀ0.0952076 a.u. for the
C„C group. A maximum positive region localized on the S atom
bond has value of +0.0708951 a.u. From this results, we can say
that the S atom indicates the strongest attraction and C„C group
indicates the strongest repulsion.
Fig. 10. Molecular electrostatic potential map (MEP) of BPTPA.
The maximum absorption values were observed at 277 and 287,
278 and 287, 279 and 286 nm in water, ethanol and chloroform,
respectively. Calculated kmax values obtained with B3LYP/6-
311++G(d,p) are 260 and 248 nm in water which are HOMO ? LU-
MO and HOMOꢀ6 ? LUMO transition, respectively. In ethanol and
chloroform, these values are calculated at 260 and 248 nm which
are the same transition in water (see Table 4).
In the present study, 3D plots of molecular electrostatic poten-
tial (MEP) of BPTPA is illustrated in Fig. 10. The MEP which is a plot
of electrostatic potential mapped onto the constant electron den-
sity surface with together HOMO and LUMO (Fig. 11). The MEP is
a useful property to study reactivity given that an approaching
electrophile will be attracted to negative regions (where the elec-
tron distribution effect is dominant). The importance of MEP lies
in the fact that it simultaneously displays molecular size, shape
as well as positive, negative and neutral electrostatic potential re-
Nonlinear optical (NLO) effects
NLO properties has been of great interest by the recent years.
Because some synthesized novel materials show efficient nonlinear
optical that are used telecommunication, potential applications in
modern communication technology, optical signal processing and
data storage.
In this study, the electronic dipole moment, molecular polariz-
ability, anisotropy of polarizability and molecular first hyperpolar-

566
M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
izability of present compound were investigated. The polarizability
and hyperpolarizability tensors (axx azz and bxxx
bxxy, bxyy, byyy, bxxz, bxyz, byyz, bxzz, byzz, bzzz) can be obtained by a fre-
quency job output file of Gaussian. However, and b values of
Table 6
,
axy
,
ayy
,
axz
,
ayz
,
,
Mulliken atomic charges of BPTPA.
C1
C2
C3
C4
C5
C6
C7
C8
ꢀ0.410936
ꢀ0.225112
ꢀ0.241833
0.857943
ꢀ0.060981
ꢀ0.279943
ꢀ1.075578
ꢀ0.187034
ꢀ0.216641
0.038056
H19
H20
H21
H22
H23
H24
H25
H26
H27
H28
H29
H30
H31
H32
H33
H34
H35
H36
H41
H43
H44
N11
0.154479
0.179973
0.174833
0.163873
0.179023
0.171741
0.179203
0.158184
0.191107
0.148431
0.091043
0.144600
0.133513
0.150598
0.174981
0.152493
0.178346
0.168712
0.161396
0.258678
0.284591
0.178015
a
Gaussian output are in atomic units (a.u.) so they have been con-
verted into electronic units (esu) (
a
; 1 a.u. = 0.1482 ꢁ 10ꢀ24 esu,
b; 1 a.u. = 8.6393 ꢁ 10ꢀ33 esu). The mean polarizability (
a), anisot-
ropy of polarizability (Da) and the average value of the first hyper-
polarizability hbi can be calculated using the below equations.
C9
1
3
C10
C12
C13
C14
C15
C16
C17
C18
C37
C38
C39
C40
C45
S42
atot
¼
ðaxx
þ
ayy
þ
azz
Þ
ꢀ0.872355
1.078712
h
i
1
2
ꢀ0.319091
ꢀ0.256026
ꢀ0.399857
ꢀ0.310507
ꢀ0.095033
ꢀ0.715620
ꢀ1.109054
1.201769
1
2
2
2
D
a
¼
ð
axx
ꢀ
ayyÞ þðayy
ꢀ
azzÞ þðazz
ꢀ
axxÞ þ6a2xz þ6ax2y þ6a2yz
pffiffiffi
2
h
i
1
2
2
2
2
hbi¼ ðbxxx þbxyy þbxzzÞ þðbyyy þbyzz þbyxxÞ þðbzzz þbzxx þbzyy
Þ
0.280355
In Table 5, the calculated parameters described above and elec-
tronic dipole moment {li (i = x, y, z) and total dipole moment ltot
ꢀ0.715620
}
ꢀ0.575821
for title compound are listed. The total dipole moment can be calcu-
lated using the following equation.
1
2
ltot ¼ ðl2x
þ
ly2
þ
lz2
Þ
It is well known that the higher values of dipole moment, polarizabil-
ity, and hyperpolarizability are important for more active NLO prop-
erties. The calculated dipole moment is equal to 0.404117 Debye (D).
The highest value of dipole moment is observed for component
this direction, this value is equal to 0.388142 D. Total polarizability
and anisotropy of polarizability are calculated as
lz. In
(
atot
)
(Da)
43.094626 and 102.972128 esu. The first hyperpolarizability value
btot of the title compound is equal to 18.622910 ꢁ 10ꢀ31 esu. The
hyperpolarizability b was dominated by the longitudinal compo-
nents of bxxx. Domination of particular component indicates on a sub-
stantial delocalization of charges in this direction.
The polarizability and the first hyperpolarizability of title mole-
cule is ca. 10 and 2 times greater than those of urea (a and b of urea
are 9.868774 ꢁ 10ꢀ24
,
and 7.803240 ꢁ 10ꢀ31 esu obtained by
B3LYP/6-311++G(d,p) method. That is to say, the title compound
can be used as a good candidate of NLO materials.
Fig. 12. Mulliken atomic charge distribution of BPTPA.
Mulliken atomic charges
charges are computed by the DFT/B3LYP method 6-311++G(d,p)
basis set.
The computed of reactive atomic charges plays an important
role in the application of quantum mechanical calculations the
molecular system. The Mulliken atomic charges of title molecule
is presented in Table 6 and shown in Fig. 12. The Mulliken atomic
As can be seen in Table 6, all hydrogen atoms and N atom have a
net positive charge. The maximum negative charge C38, C7, C12,
C37, C45 and sulfur atom which are donor atoms and net positive
charge on hydrogen and nitrogen atoms, which are acceptor atoms.
The donor and acceptor atoms may suggest the presence of both
inter-molecular hydrogen bonding in the crystalline phase.
Table 5
The dipole moments
l
(D), the polarizability
a
(a.u.), the average polarizability ao
(esu), the anisotropy of the polarizability
of BPTPA.
Da (esu), and the hyperpolarizability b (esu)
Conclusions
lx
ly
lz
l0
axx
axy
ayy
axz
ayz
azz
atotal
ꢀ0.058481
0.096105
bxxx
bxxy
bxyy
byyy
bxxz
bxyz
byyz
bxzz
byzz
bzzz
bx
206.904023
ꢀ55.934514
ꢀ33.644834
143.272517
64.436064
ꢀ46.976706
ꢀ59.576790
20.290236
ꢀ4.205349
ꢀ50.618112
193.549424
83.132654
ꢀ45.758839
18.622910
The novel compound (S)-N-benzyl-1-phenyl-5-(thiophen-3-yl)-
4-pentyn-2-amine was synthesized for the first time and several
spectroscopic properties were studied using experimental tech-
niques (FT-IR, NMR and UV) and tools derived from the density
functional theory. The optimized geometric parameters of mole-
cule were interpreted and compared with structurally similar com-
pounds. The vibrational FT-IR spectrum of molecule was recorded.
The computed vibrational wavenumbers were assigned and com-
pared with experimental values. The magnetic properties of the ti-
tle compound were calculated and compared with the
experimental data which are obtained from 1H and 13C NMR spec-
tra. The TDOS, PDOS and OPDOS diagrams were presented and
ꢀ0.388142
0.404117
391.485183
ꢀ30.016936
232.783937
3.844925
ꢀ9.629177
248.091735
43.094626
102.972128
D
a
by
bz
b

M. Karabacak et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 97 (2012) 556–567
567
[27] A.J. Williams, S. Chaktong, S. Gray, R.M. Lawrence, T. Gallagher, Org. Lett. 5
(2003) 811–814.
[28] M.J. Frisch et al., GAUSSIAN 09, Revision A.1, Gaussian Inc., Wallingford, CT,
2009.
interpreted. Some of the groups such as phenyl and thiophene
rings contribute similarly to the TDOS of BPTPA. The OPDOS dia-
grams showed interactions for five groups and C„C M thiophene
have significant anti-bonding character. The electronic absorption
properties were also calculated and experimental electronic spec-
trum was recorded. Furthermore, the polarizability, first hyperpo-
larizability and total dipole moment of title molecule were
calculated and the results are discussed. These results indicate that
the studied compound is a good candidate of nonlinear optical
materials. We hope that the results of this study will help research-
ers to synthesis of new materials.
[29] H.B. Schlegel, J. Comput. Chem. 3 (1982) 214–218.
[30] N. Sundaraganesan, S. Ilakiamani, H. Saleem, P.M. Wojciechowski, D.
Michalska, Spectrochim. Acta A 61 (2005) 2995–3001.
[31] J. Baker, A.A. Jarzecki, P. Pulay, J. Phys. Chem. A 102 (1998) 1412–1424.
[32] K. Wolonski, J.F. Hinton, P. Pulay, J. Am. Chem. Soc. 112 (1990) 8251–8260.
[33] E. Runge, E.K.U. Gross, Phys. Rev. Lett. 52 (1984) 997–1000.
[34] M. Petersilka, U.J. Gossmann, E.K.U. Gross, Phys. Rev. Lett. 76 (1966) 1212–
1215.
[35] R. Bauernschmitt, R. Ahlrichs, Chem. Phys. Lett. 256 (1996) 454–464.
[36] T.W. Hambley, H.K. Chan, I. Gonda, J. Am. Chem. Soc. 108 (1986) 2103–2105.
[37] M. Nethaji, V. Pattabhi, G.R. Desiraju, Acta Cryst. C 44 (1988) 275–277.
[38] S. LoÈhr, M. Yonemura, A. Orita, N. Imai, H. Akashi, J. Otera, Acta Cryst. E59
(2003) 594–595.
Appendix A. Supplementary data
[39] B.G. Johnson, P.M. Gill, J.A. Pople, J. Chem. Phys. 98 (1993) 5612–5626.
[40] D. Sajan, L. Joseph, N. Vijayan, M. Karabacak, Spectrochim. Acta A 81 (2011)
85–98.
[41] L.J. Bellamy, The Infrared Spectra of Complex Molecules, vol. 2, Chapman and
Hall, London, 1980.
Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.saa.2012.05.087.
[42] M. Silverstein, G.C. Basseler, C. Morill, Spectrometric Identification of Organic
Compounds, Wiley, New York, 1981.
[43] L.J. Bellamy, R.L. Williams, Spectrochim. Acta 9 (1957) 341–345.
[44] V.K. Rastogi, M.A. Palafox, R.P. Tanwar, L. Mittal, Spectrochim. Acta A 58 (2002)
1987–2004.
[45] G. Varsanyi, Assignments of Vibrational Spectra of Seven Hundred Benzene
Derivatives, vol. 1, Adam Hilger, 1974.
[46] D. Sajan, J. Binoy, B. Pradeep, K. Venkatakrishnan, V.B. Kartha, I.H. Joe, V.S.
Jayakumar, Spectrochim. Acta A 60 (2004) 173–180.
References
[1] H.J. Bertram, R. Emberger, M. Guntrt, H. Sommer, P. Werkhoff, Recent Dev.
Flavor Frag. Chem. 11 (1993) 241–259.
[2] J.B. Press, Chem. Heterocycl. Compd. 44 (1991) 397–502.
[3] D. Bloor, Chem. Ber. 31 (1995) 385–387.
[4] H.S. Nalwa, Adv. Mater. 5 (1993) 341–358.
[5] I.Y. Wu, J.T. Lin, Ch.S. Li, W.C. Wang, T.H. Huang, Y.S. Wen, T. Chow, Ch. Tsai,
Tetrahedron 55 (1999) 13973–13982.
[6] V.P. Rao, A.K.Y. Jen, Y.J. Cai Chem, Soc, Chem. Commun. 10 (1996) 1237–1238.
[7] M. Irie, Chem. Rev. 100 (2000) 1685–1716.
[47] K. Wolinski, J.F. Hinton, P. Pulay, J. Am. Chem. Soc. 112 (1990) 8251–8260.
[48] D. Lin-Vien, N.B. Colthup, W.G. Fateley, J.G. Grasselli, The Handbook of Infrared
and Raman Characteristic Frequencies of Organic Molecules, Academic Press,
Boston, MA, 1991.
[8] G.Ch. Barbarella, Eur. J 8 (2002) 5072–5077.
[49] J. Svoboda, J. Sedlacek, J. Zednik, G. Dvorakova, O. Trhlikova, D. Redrova, J.
Polym. Sci. A Polym. Chem. 46 (2008) 2776–2787.
[50] L.J. Bellamy, Advances in Infrared Group Frequencies, Methuen London, 1968.
[51] R. Ditchfield, Mol. Phys. 27 (1974) 789–807.
[9] T. Nishiumi, M. Higuchi, K. Yamamoto, Macromolecules 36 (2003) 6325–6332.
[10] M. Heeney, S. Tierney, I. McCulloch, S. Higgins, D. Crouch, P. Skabara, European
Patent (Patent applicant) 1 (2005) 1.
[11] G. Barbarella, M. Zambianchi, Tetrahedron 50 (1994) 11249–11256.
[12] J.S. Kwiatkowski, J. Leszczynski, I. Teca, J. Mol. 451 (1997) 436–437.
[13] F.J. Ramirez, V. Hernandez, J.T. Lopez Navarrete, J. Compt, Chem. 15 (1994)
405–423.
[14] T.D. Klots, R.D. Chirico, W.V. Steele, Spectrochim. Acta A 50 (1994) 765–795.
[15] D.K. Singh, S.K. Srivastava, A.K. Ojha, B.P. Asthana, J. Mol. Struct. 892 (2008)
384–391.
[16] A. Coruh, F. Yilmaz, B. Sengez, M. Kurt, M. Cinar, M. Karabacak, Struct. Chem.
22 (2011) 45–56.
[17] M. Rico, J.M. Orza, J. Morcillo, Spectrochim. Acta 21 (1965) 689–719.
[18] M.A. Palafox, G. Tardajos, A.G. Martines, V.K. Rastogi, D. Mishra, S.P. Ojha, W.
Kiefer, Chem. Phys. 340 (2007) 17–31.
[52] M. Cossi, V. Barone, B. Mennucci, J. Tomasi, Chem. Phys. Lett. 286 (1998) 253–
260.
[53] K. Pihlajer, E. Kleinpeter (Eds.), Carbon 13Chemical Shifts Instructure and
Spectrochemical Analysis, VCH Publishers, Deerfield Beach, 1994.
[54] N. Subramania, N. Sundaraganesan, J. Jayabharathi, Spectrochim. Acta A 76
(2010) 259–269.
[55] H.O. Kalinowski, S. Berger, S. Brawn, Carbon 13 NMR Spectroscopy, John Wiley
and Sons, Chichester, 1988.
[56] R. Hoffmann, Solids and Surfaces: A Chemist’s View of Bonding in Extended
Structures, VCH Publishers, New York, 1988.
[57] J.G. Malecki, Polyhedron 29 (2010) 1973–1979.
[58] N.M. O’Boyle, A.L. Tenderholt, K.M. Langner, J. Comp. Chem. 29 (2008) 839–
845.
[59] M. Chen, U.V. Waghmare, C.M. Friend, E. Kaxiras, J. Chem. Phys. 109 (1998)
6854–6860.
[60] K. Fukui, Science 218 (1982) 747–754.
[19] M. Karabacak, E. Kose, M. Kurt, J. Raman Spectrosc. 41 (2010) 1085–1097.
[20] Z. Meng, W.R. Carper, J. Mol. Struct. Theochem. 588 (2002) 45–53.
[21] A. Atac, M. Karabacak, C. Caglar, E. Kose, Spectrochim. Acta A 85 (2012) 145–
154.
[22] A.M. Asiri, M. Karabacak, M. Kurt, K.A. Alamry, Spectrochim. Acta A 82 (2011)
444–455.
[61] B. Kosar, C. Albayrak, Spectrochim. Acta A 78 (2011) 160–167.
[62] R.G. Pearson, Proc. Natl. Acad. Sci. USA 83 (1986) 8440–8841.
[63] J.S. Murray, K. Sen, Molecular Electrostatic Potentials, Concepts and 399
Applications, Elsevier, Amsterdam, 1996.
[64] E. Scrocco, J. Tomasi, in: P. Lowdin (Ed.), Advances in Quantum Chemistry,
Academic Press, New York, 1978.
[23] P. Hohenberg, W. Kohn, Phys. Rev. 136 (1964) B864–B871.
[24] A.D. Becke, J. Chem. Phys. 98 (1993) 1372–1377.
[25] C. Lee, W. Yang, R.G. Parr, Phys. Rev. B 37 (1988) 785–789.
[26] M. Eskici, A. Karanfil, M.S. Ozer, C. Sarıkurkcu, Tetrahedron Lett. 52 (2011)
6336–6341.