Vibrational spectroscopic studies and computational study of 4-fluoro-N-(2′-hydroxy-4′-nitrophenyl)phenylacetamide

Article abstract of DOI:10.1016/j.molstruc.2011.03.022

Fourier-transform infrared (FT-IR) and FT-Raman spectra of 4-fluoro-N-(2′-hydroxy-4′-nitrophenyl)phenylacetamide were recorded and analyzed. A surface-enhanced Raman scattering (SERS) spectrum was recorded in silver colloid. The vibrational wavenumbers an

Full text of DOI:10.1016/j.molstruc.2011.03.022

Journal of Molecular Structure 994 (2011) 223–231
Contents lists available at ScienceDirect
Journal of Molecular Structure
journal homepage: www.elsevier.com/locate/molstruc
Vibrational spectroscopic studies and computational study
0
0
of 4-fluoro-N-(2 -hydroxy-4 -nitrophenyl)phenylacetamide
a,c,
⇑
b,1
c,1
a
d
Y. Sheena Mary
, C. Yohannan Panicker , Hema Tresa Varghese , K. Raju , Tugba Ertan Bolelli ,
d
e
e
Ilkay Yildiz , Carlos M. Granadeiro , Helena I.S. Nogueira
a
Department of Physics, University College, Trivandrum, Kerala, India
Department of Physics, TKM College of Arts and Science, Kollam, Kerala, India
Department of Physics, Fatima Mata National College, Kollam, Kerala, India
Faculty of Pharmacy, Department of Pharmaceutical Chemistry, Ankara University, Tandogan 06100, Ankara, Turkey
Department of Chemistry, CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
b
c
d
e
a r t i c l e i n f o
a b s t r a c t
0
0
Article history:
Fourier-transform infrared (FT-IR) and FT-Raman spectra of 4-fluoro-N-(2 -hydroxy-4 -nitrophenyl)phen-
ylacetamide were recorded and analyzed. A surface-enhanced Raman scattering (SERS) spectrum was
recorded in silver colloid. The vibrational wavenumbers and corresponding vibrational assignments were
examined theoretically using quantum mechanical calculations. The red shift of the NH stretching wave-
number in the IR spectrum from the calculated wavenumber indicates the weakening of NH bond result-
Received 28 December 2010
Received in revised form 8 March 2011
Accepted 8 March 2011
Available online 12 March 2011
2 2
ing in proton transfer to the neighboring oxygen atom. The presence of CH and NO modes in the SERS
Keywords:
Acetamide
FT-IR
FT-Raman
DFT calculations
SERS
spectrum indicates the nearness of these groups to the metal surface, which affects the orientation and
metal molecule interaction. The presence of phenyl ring deformation bands, show a tilted orientation of
the molecule with respect to the silver surface. The first hyperpolarizability and predicted infrared inten-
sities are reported. The calculated first hyperpolarizability is comparable with the reported values of sim-
ilar structures and is an attractive object for further studies of nonlinear optics.
Ó 2011 Elsevier B.V. All rights reserved.
1
. Introduction
N-Phenyl benzamides are important and biologically active
functional methods. Gas phase structures of fundamental amides,
formamide [6] and acetamide [7] were determined by electron dif-
fraction and their crystal structures were studied by X-ray and
neutron diffraction [8–12]. The crystal structures of benzamide
were determined by X-ray [13] and neutron diffraction [14]. Near
infrared spectroscopic studies of the hydrogen bonding between
thioacetamide and N,N-disubstituted benzamide derivatives in
compounds [1]. Some N-(o-hydroxypheny)benzamides and pheny-
lacetamides have been reported as possible metabolites of antimi-
crobial active benzoxazoles. Synthesis and microbiological activity
of some N-(2-hydroxy-4-substitutedphenyl)benzamides, pheny-
lacetamides and furamides as possible metabolites of antimicrobial
active benzoxazoles are reported by Aki-Sener et al. [2]. Benzamide
derivatives which are the possible metabolites of benzoxazoles
show various type of biological properties such as antihelmenthic,
antihistaminic, antifungal and antibacterial [1]. Vibrational
spectroscopic studies and DFT calculations of 4-fluoro-N-(2 -hy-
droxy-4 -nitrophenyl) benzamide was reported by Ushakumari
et al. [3]. The intra molecular hydrogen bond in 2-hydroxy-benz-
amides are reported by Kawski et al. [4]. Arslan et al. [5] reported
the molecular structure and vibrational spectra of 2-chloro-N-
4
CCl is reported by Choi et al. [15]. Molecular structure benzamide
was studied by gas phase electron diffraction [16]. Biagi et al. [17]
reported the synthesis and biological activity of novel substituted
benzanilides as potassium channel activators. Rho et al. [18] re-
ported the studies on depigmenting activities of dihydroxyl benz-
amide derivatives containing adamantane moiety. DFT and ab
initio study of structure of dyes derived from 2-hydroxy and 2,4-
hydroxy benzoic acids are reported by Dabbagh et al. [19] Nishik-
awa et al. [20] reported the internal rotations of aromatic polya-
mides theoretically. In the present work, the IR, Raman, SERS and
theoretical calculations of the wavenumbers for the title com-
pound are reported. Nonlinear optics deals with the interaction
of applied electromagnetic fields in various materials to generate
new electromagnetic fields, altered in wavenumber, phase, or
other physical properties [21]. Organic molecules able to manipu-
late photonic signals efficiently are of importance in technologies
such as optical communication, optical computing, and dynamic
0
0
(
diethylcarbamothioyl)benzamide by Hartree–Fock and density
⇑
Corresponding author at: Department of Physics, University College, Trivan-
drum, Kerala, India.
E-mail address: sypanicker@rediffmail.com (Y.S. Mary).
Temporary address: Department of Physics, Mar Ivanios College, Nalanchira,
1
Trivandrum, Kerala, India.
0
022-2860/$ - see front matter Ó 2011 Elsevier B.V. All rights reserved.
doi:10.1016/j.molstruc.2011.03.022

2
24
Y.S. Mary et al. / Journal of Molecular Structure 994 (2011) 223–231
Fig. 1. FTIR spectrum of 4-fluoro-N-(2-hydroxy-4-nitrophenyl)phenylacetamide.
Fig. 3. SERS spectrum of 4-fluoro-N-(2-hydroxy-4-nitrophenyl)phenylacetamide.
image processing [22,23]. Phenyl substituents can increase molec-
ular hyperpolarizability [24,25] a result described as surprising.
The purity of the compound was checked by TLC (Merck TLC
plates Silica gel 60 F254) using solvents S1 (CHCl /MeOH 15:1).
3
Many organic molecules, containing conjugated
p electrons and
The plates were visualized using UV light. Melting points (uncor-
rected) was determined using a capillary melting point apparatus
Buchi SMP 20 and Electrothermal 9100): 226–228 °C. Yield was
calculated after recrystallization. Yield 33%. The IR spectrum
Fig. 1) was recorded on a Jasco FT-IR-420 spectrometer with KBr
characterized by large values of molecular first hyperpolarizabili-
ties, were analyzed by means of vibrational spectroscopy [26]. In
this context, the hyperpolarizability of the title compound is calcu-
lated in the present study.
(
(
disks. The FT-Raman spectra (Figs. 2 and 3) was obtained on a Bru-
ker RFS 100/S, Germany. For excitation of the spectrum, the emis-
sion of a Nd:YAG laser was used, excitation wavelength 1064 nm,
maximal power 150 mW, measurement on solid sample. The aque-
ous silver colloid used in the SERS experiments was prepared by
reduction of silver nitrate by sodium citrate, using the Lee-Meisel
method [28]. Solutions of the title compound were made up in eth-
2
. Experimental
The chemicals were purchased from the commercial venders
and were used without purification. The reactions were monitored
and the purity of the product was checked by thin layer chroma-
tography (TLC). Silica gel 60 F254 chromatoplates were used for
TLC. The solvent systems were chloroform/methanol (15:1). Thio-
nyl chloride (1.5 ml) and 4-fluorophenyl acetic acid (0.5 mmol)
were refluxed in benzene (5 ml) at 80° for 3 h, and then excess
thionyl chloride was removed in vacuo [27]. The residue was dis-
solved in ether (10 ml) and the solution added during 1 h to a stir-
red, ice–cold mixture of 2-amino-5-nitrophenol (0.5 mmol),
sodiumbicarbonate (0.5 mmol), diethyl ether (10 ml), and water
3
anol (0.1 mmol in 1 cm of solvent) and transferred by a microsy-
3
ringe into the silver colloid (10
l
L in 1 cm of colloid) such that the
ꢀ3
ꢀ3
overall concentration was 10 mol dm . Colloid aggregation was
induced by addition of an aqueous solution of MgCl
2
(1 drop of a
ꢀ3
2
mol dm solution). Polyvinylpyrrolidone was then used to stabi-
3
lize the colloid (1 drop of 0.1 g/10 cm aqueous solution). The final
colloid mixture was placed in a glass tube and the Raman spectrum
registered.
(
10 ml). The mixture was stirred overnight at room temperature
The 1H NMR spectra was recorded employing a VARIAN
and filtered. After the precipitate was washed with water, 2 N
HCl and water, respectively, and finally with ether, compound
was obtained. The crude product was purified by recrystallization
from ethanol.
Mercury 400 MHz FT spectrometer, chemical shifts (d) are in
Fig.
4. Optimized
geometry
of
4-fluoro-N-(2-hydroxy-4-nitrophenyl)
Fig.
2. FT-Raman
spectrum
of
4-fluoro-N-(2-hydroxy-4-nitrophenyl)
phenylacetamide.
phenylacetamide.

Y.S. Mary et al. / Journal of Molecular Structure 994 (2011) 223–231
225
ppm relative to TMS, and coupling constants (J) are reported in
Hertz. Elemental analysis was taken on a Leco 932 CHNSAO ana-
lyzer. The results of the elemental analysis (C, H, N) was within
±
0.4% of the calculated amounts. Elemental analyses: calculated:
1
C, 57.93; H, 3.82; N, 9.65; found: C, 57.68; H, 3.87; N, 9.649.
NMR (DMSO-d ) d ppm, J = Hz: 3.83 (s, 2H, CH ); 7.08–7.18 (m,
H, 3–H, 5–H); 7.35–7.40 (m, 2H, 2–H, 6–H); 7.65–7.71 (m, 2H,
H
6
2
2
3
1
0
0
0
0
–H, 5 –H); 8.26 (d, 1H, J = 8.8, 6 –H); 9.67 (s, 1H, OH); 11.09 (s,
H, NH).
3
. Computational details
The vibrational wavenumbers were calculated using the Gauss-
ian03 software package on a personal computer [29]. The compu-
⁄
⁄
tations were performed at HF/6-31G , B3PW91/6-31G and B3LYP/
6
⁄
-31G levels of theory to get the optimized geometry (Fig. 4) and
vibrational wavenumbers of the normal modes of the title com-
pound. Parameters corresponding to optimized geometry of the ti-
tle compound are given in Table S1 (Supporting information). The
T V J T
DFT partitions, the electronic energy E = E + E + E + EXC, where E ,
E
V
and E are electronic kinetic energy, electron nuclear attraction
J
Fig. 6. Profile of potential energy scan for the torsion angle N26AC24AC21AC3.
and electron–electron repulsion terms, respectively. The electron
correlation is taken into account in the DFT via the exchange–cor-
relation term EXC, which includes exchange energy arising from the
anti-symmetry of quantum mechanical wave function and dy-
namic correlation in the motion of individual electron, and it
makes DFT dominant over conventional HF procedure [30]. DFT
calculations were carried out with Becke’s three-parameter hybrid
model using the Lee–Yang-Parr correlation functional (B3LYP)
method. Molecular geometries were fully optimized by Berny’s
optimization algorithm using redundant internal coordinates. Har-
monic vibrational wavenumbers were calculated using analytic
second derivatives to confirm the convergence to minima in the
potential surface. At the optimized structure of the examined spe-
cies, no imaginary wavenumber modes were obtained, proving
that a true minimum on the potential surface was found. The opti-
mum geometry was determined by minimizing the energy with re-
spect to all geometrical parameters without imposing molecular
symmetry constraints. The DFT hybrid B3LYP functional tends also
to overestimate the fundamental modes; therefore scaling factors
have to be used for obtaining a considerably better agreement with
experimental data [31]. Scaling factors 0.9613 and 0.8929 has been
uniformly applied for the DFT and HF calculated wavenumbers
Fig. 7. Profile of potential energy scan for the torsion angle H27AN26AC24AC21
.
[
30]. The observed disagreement between theory and experiment
could be a consequence of the anharmonicity and of the general
tendency of the quantum chemical methods to overestimate the
force constants at the exact equilibrium geometry [32]. The assign-
ments of the calculated wavenumbers are aided by the animation
option of MOLEKEL program, which gives a visual presentation of
the vibrational modes [33,34]. Potential energy surface scan stud-
ies has been carried out to understand the stability of planar and
non-planar structures of the molecule. The profiles of potential en-
3 3
ergy surface for torsion angles O25AC24AC21AC , N26AC24AC21AC
and H27AN26AC24AC21 are given in Figs. 5–7. The energy is mini-
mum for ꢀ153.7° (ꢀ1050.26281 Hartree), 28.8° (ꢀ1050.26130
Hartree) and ꢀ4.5° (ꢀ1050.26271 Hartree) for the torsion angles.
4
. Results and discussion
4.1. IR and Raman spectra
The observed IR, Raman bands with the relative intensities and
Fig. 5. Profile of potential energy scan for the torsion angle O25AC24AC21AC
3
.
calculated (scaled) wavenumbers and assignments are given in

2
26
Y.S. Mary et al. / Journal of Molecular Structure 994 (2011) 223–231
Table 1. Fluorine atoms directly attached to the aromatic ring give
rise bands [35] in the region 1100–1270 cm . Many of these com-
pounds [35] including the simpler ones with one fluorine only on
nificant contribution form phenyl ring stretching modes. The
stretching of the hydroxyl group with respect to the phenyl moiety
ꢀ1
ꢀ1
ꢀ1
t
(CAO)
h
appears at 1270 cm in the IR spectrum, 1268 cm in
ꢀ
1
ꢀ1
the ring, absorb near 1230 cm . The
1
t
CAF is reported at 1157,
Raman spectrum and the calculated value is 1261 cm . This band
is expected [35,41,42] in the region 1220 ± 40 cm . The out-of-
plane OH deformation is observed at 621 cm in the IR spectrum
and at 612 cm , theoretically, which is expected [38] in the region
ꢀ1
ꢀ1
ꢀ1
233 cm (IR), 1244 cm (HF) [36,37]. For the title compound,
ꢀ1
ꢀ1
the band observed at 1225 cm in the IR spectrum is assigned as
ꢀ1
ꢀ1
t
CAF mode. The DFT calculations give this mode at 1218 cm
The substitution of fluorine in the phenyl ring changes the CAC
bond lengths C AC and C AC of the benzene ring. Fluorine is
.
ꢀ1
650 ± 80 cm . For paracetamol,
t
(CAO)
1240 and 620 cm , respectively [40].
The most characteristic bands in the spectrum of nitro com-
pounds are due to NO stretching, which are the two most useful
h
and cOH are reported at
ꢀ1
1
6
5
6
highly electronegative and thus to obtain additional electron den-
sity it attempts to draw it from the neighbouring atoms, which
move closer together in order to share the remaining electrons
more easily as a result. Due to this, the bond angle A(1,6,5) is found
to be 122.4° in the present case, which is 120° for normal benzene.
2
group wavenumbers, not only because of their spectral position
but also for their strong intensity [38]. In nitro compounds the anti-
2
symmetric NO stretching vibrations [38] are located in the region
ꢀ
1
Similarly, the bond lengths C
.3895 Å, respectively, while for normal benzene it is 1.3864 Å [37].
The vibrations of the CH group (the asymmetric stretch
symmetric stretch CH , scissoring vibrations dCH and the wag-
ging vibration CH ) appears in the regions 2940 ± 20, 2885 ± 45,
440 ± 10 and 1340 ± 25 cm , respectively [35,38]. These bands
1
AC
6
and C
5
AC
6
are 1.3920 Å and
2
1580 ± 80 cm . The symmetric NO stretching vibrations [38] are
ꢀ1
1
expected in the region 1380 ± 20 cm . In substituent nitrobenz-
ꢀ
1
2
t
2
asCH ,
enes,
s 2
t NO appears strongly at 1345 ± 30 cm , in 3-nitropyridine
ꢀ1
t
s
2
2
[43] at 1330 ± 20 cm , and in conjugated nitroalkenes [44] at
ꢀ
1
x
2
1345 ± 15 cm . In the present case the bands observed at
ꢀ1
ꢀ1
ꢀ1
1
1555 cm in the IR spectrum and 1534 cm in the Raman spec-
ꢀ1
ꢀ1
are observed at 2942 cm in the IR spectrum, 2992, 2927 cm
in the Raman spectrum and at 2999, 2938, 1456, 1301 cm theo-
retically for the title compound. The twisting and rocking modes of
trum are assigned as asymmetric NO
2
modes. The
t
s
NO
2
mode is
ꢀ1
ꢀ1
observed at 1391 cm in the IR spectrum. The DFT calculations
ꢀ1
give 1527 and 1396 cm
as asymmetric and symmetric NO
2
the CH
2
group appear in the regions [38] 1260 ± 10 and
stretching modes respectively. According to some investigators
[45–47] the NO scissors [38] occur in the region 850 ± 60 cm
2
when conjugated to C@ or aromatic molecules, with a contribution
ꢀ1
ꢀ1
8
00 ± 25 cm . These modes are also assigned (Table 1).
The C@O stretching vibrations [38,39] are expected in the
ꢀ1
ꢀ1
region 1715–1680 cm
appears at 1663 cm in IR and 1658 cm in Raman spectrum.
The DFT calculations give this mode at 1639 cm . El-Shahawy
et al. [40] reported a value 1640 cm in the IR spectrum as
for paracetamol. The dC@O in-plane deformation [38] has been
found in the region 625 ± 70 cm and the band at 638 cm in
Raman spectrum and 641 cm in (DFT) is assigned as this mode.
and in the present study this mode
of the
zene, dNO
t
CN, which is expected to be near 1120 cm . For nitroben-
ꢀ1
ꢀ1
ꢀ1
2
is reported at [38] 852 cm , for H2C@CHNO
890 cm , and for 1,3-dinitrobenzene at 904 and 834 cm . For
the title compound, the DFT calculations give the band at
2
at
ꢀ1
ꢀ1
ꢀ1
ꢀ1
tC@O
ꢀ
ꢀ1
1
862 cm as the deformation band of NO
869 cm in Raman spectrum is assigned as dNO
pounds, the wagging mode
2
. The band observed at
. In aromatic com-
is observed at 740 ± 50 cm with
ꢀ1
ꢀ1
2
ꢀ1
ꢀ1
x
NO
2
The C@O out-of-plane deformation [38] is in the range
a moderate to strong intensity, a region in which
c
CH is also active
ꢀ1
ꢀ1
5
4
4
40 ± 80 cm , and the DFT calculations give this mode at
[38].
x
NO
2
is reported at 701 and 728 cm for 1,2-dinitrobenzene
ꢀ1
ꢀ1
ꢀ1
86 cm and weak bands are observed at 499 cm in IR and at
and at 710 and 772 cm for 1,4-dinitrobenzene [38]. For the title
compound, the band at 744 cm in the IR spectrum, 759 cm in
the Raman spectrum and 762 cm (DFT) is assigned as
ꢀ1
ꢀ1
ꢀ1
84 cm in the Raman spectrum.
ꢀ1
The NH stretching vibration appears strongly and broadly in the
x
NO
2
ꢀ
1
region [38] 3390 ± 60 cm . For the title compound the strong
mode. In aromatic compounds, the rocking mode
qNO
2
is active
ꢀ
1
ꢀ1
ꢀ1
band at 3343 cm in the IR spectrum and 3340 cm in Raman
spectrum is assigned as NH mode. The calculated value for this
mode is 3433 cm . The NH stretching wavenumber is red shifted
in the region 545 ± 45 cm . Nitrobenzene [38] shows this rocking
ꢀ1
t
mode at 531 cm . In the present case the DFT calculations give this
ꢀ1
ꢀ1
rocking mode of NO
the NO
2
533 cm . Sundaraganesan et al. [48] reported
ꢀ1
ꢀ1
by 90 cm in the IR spectrum with a strong intensity from the
computed wavenumber, which indicates the weakening of the
NAH bond resulting in proton transfer to the neighboring oxygen
2
deformation bands at 839, 744 and 398 cm (experimen-
tally) and at 812, 716, 703 and 327 cm theoretically.
ꢀ1
Since the identification of all the normal modes of vibration of
large molecules is not trivial, we tried to simplify the problem by
considering each molecule as a substituted benzene. Such an idea
has already been successfully utilized by several workers for the
vibrational assignments of molecules containing multiple homo
and hetero aromatic rings [37]. In the following discussion, the
tri-substituted and para substituted phenyl rings are designated
as ring I and II, respectively. The modes in the two phenyl rings will
differ in wavenumber and the magnitude of splitting will depend
on the strength of interaction between different parts (internal
coordinates) of the two rings. For some modes, this splitting is so
such that they may be considered as quasi-degenerate, and for
other modes a significant amount of splitting may be observed
[37]. The aromatic CH stretching vibrations [38] absorb weakly to
[
39]. The CNH vibration in which N and H atoms move in opposite
direction of carbon atom in the amide moiety appears at
ꢀ1
1
497 cm theoretically, and the CNH vibration in which N and
H atoms move in the same direction of carbon atom in the amide
group appears at 1217 (DFT) [35,40,41]. The NH rock in the plane
ꢀ
1
observed at 1162 (IR), 1158 (Raman) and at 1166 cm theoreti-
cally [40]. The out-of-plane wagging [38] of NH is moderatively ac-
ꢀ1
tive with a broad band in the region 790 ± 70 cm and the band
ꢀ
1
7
63 cm (DFT) is assigned as this mode. El-Shahawy et al. [40] re-
ꢀ1
ported a value 720 cm for this mode. The CAN stretching vibra-
tion [38] coupled with dNH, is moderately to strongly active in the
region 1275 ± 55 cm . El-Shahawy et al. [40] observed a band at
320 cm in the IR spectrum as this
case, the band at 1339 cm in the IR spectrum and 1335 cm in
ꢀ1
ꢀ
1
1
t
CAN mode. In the present
ꢀ1
ꢀ1
ꢀ1
moderately between 3120 and 3000 cm . The B3LYP calculations
ꢀ1
Raman spectrum is assigned as this mode. The DFT calculations
give bands in the range 3077–3160 cm as
tCH stretching modes
ꢀ1
give the corresponding band at 1325 cm
The OH group provides three normal vibrations
OH. The DFT calculations give the OH band at 3556 cm . The
in-plane OH deformation [38] is expected in the region
.
of the phenyl rings. Experimentally, we have observed bands at
ꢀ
1
t
OH, dOH and
3113, 3046 cm
in the IR spectrum and at 3087, 3077,
CH modes. The benzene ring
ꢀ1
ꢀ1
c
t
3039 cm in the Raman spectrum as
t
possesses six ring stretching vibrations of which the four with the
highest wavenumbers occurring near 1600, 1580, 1490 and
ꢀ1
ꢀ1
ꢀ1
1
400 ± 40 cm and the band at 1428 cm (IR) and 1432 cm
ꢀ1
(
DFT) are assigned as this mode, which is not pure but contains sig-
1440 cm are good group vibrations [38]. With heavy substitu-

Y.S. Mary et al. / Journal of Molecular Structure 994 (2011) 223–231
227
Table 1
Calculated vibrational wavenumbers (scaled), measured infrared and Raman band positions and assignments for 4-
s
-N-(2-hydroxy-4-nitrophenyl)phenylacetamide.
⁄
⁄
⁄
ꢀ1
(IR) (cm
ꢀ1
ꢀ1
HF/6-31G
B3PW91/6-31G
B3LYP/6-31G
t
)
t
(Raman) (cm
)
t
(Raman) (cm ) SERS
Assignments
(cm 1
ꢀ
)
IR intensity
t
(cm
ꢀ1
)
IR intensity
t
(cm
ꢀ1
)
IR intensity
t
3
3
3
3
3
3
3
3
3
2
2
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
9
9
9
9
9
8
8
8
8
7
7
7
7
7
7
6
6
6
5
5
5
5
5
4
4
4
4
4
3
620
433
098
066
051
047
046
007
006
933
869
671
628
625
608
602
551
518
511
458
449
415
393
334
329
318
314
295
258
246
224
217
202
192
167
158
150
106
095
082
057
026
017
009
50
47
43
14
10
88
69
39
26
90
84
69
27
26
20
83
43
27
89
68
48
39
29
90
61
30
25
00
82
111.29
106.00
8.69
2.42
4.15
1.43
1.92
6.27
9.10
3640
3400
3170
3156
3156
3140
3139
3137
3134
3031
3028
1692
1620
1606
1600
1595
1565
1515
1500
1459
1440
1421
1390
1370
1340
1320
1315
1308
1275
1240
1232
1230
1219
1202
1194
1182
1132
1111
1089
1074
1030
999
992
976
955
939
913
881
871
861
855
846
828
784
730
720
718
691
644
637
605
582
547
537
536
505
493
462
457
425
407
399
385
7.69
56.57
3.47
29.20
18.65
1.42
14.84
0.65
3556
3433
3160
3139
3120
3119
3119
3081
3077
2999
2938
1639
1603
1600
1593
1585
1527
1507
1497
1456
1432
1410
1396
1365
1325
1314
1309
1301
1261
1233
1218.
1217
1209
1199
1169
1166
1142
1105
1102
1071
1013
999
959
950
938
930
909
888
862
860
830
825
820
772
763
762
719
710
690
672
641
612
583
560
546
533
527
486
455
424
419
398
377
56.69
99.28
5.89
1.83
2.35
3.97
2.64
6.26
9.44
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
t
OH
NH
3343 sbr
3340 w
CH I
CH I
CH II
CH I
CH II
CH II
CH II
3113 sbr
3046 sbr
3087 w
3077 s
3039 w
2992 w
2927 w
1658 w
1606 s
1.62
29.09
3.01
2.92
9.13
3.14
2975 w
2928 s
1651 m
1606 w
asCH
CH
2
10.07
166.08
35.34
47.76
135.85
4.16
608.47
89.57
25.30
12.31
213.47
2.56
32.43
103.28
0.61
58.70
2.34
63.53
174.32
379.35
82.10
12.17
188.86
1.10
81.90
23.71
143.56
156.78
12.41
41.61
4.25
2942 w
1663 s
1626 w
s
2
237.67
73.27
23.80
108.29
4.81
610.41
107.71
31.81
12.63
406.65
3.28
89.73
64.42
25.82
11.73
692.33
203.60
14.00
2.77
80.86
89.79
2.02
12.05
13.14
19.76
96.69
178.56
8.45
65.58
3.14
0.14
4.80
2.27
75.49
16.52
8.92
23.58
40.89
31.41
1.31
52.49
11.87
105.39
55.27
5.37
77.36
18.88
11.05
148.72
3.58
95.302
234.07
6.36
36.23
279.96
7.21
259.48
53.83
12.34
18.68
79.99
1.656
2.51
49.91
16.83
0.41
108.31
42.67
3.77
31.32
112.28
70.45
9.62
42.60
0.44
C@O
Ph I
Ph II
Ph I
Ph II
asNO
Ph II
1588 s
1555 s
1506 vs
1586 s
1534 s
1507m
2
1490 w
1460 s
Ph I,dNH
dCH
2
1428 s
1391 m
1339 s
t
t
t
t
t
t
Ph I, dOH
Ph II
1419 w
1423 w
1376 m
s
NO
Ph I
2
1362 w
1335 vvs
Ph II,
Ph I
tCN
1312 m
dCH II
CH
dCH I,
x
2
1270 w
1225 s
1268 s
1230 m
t(CAO)
h
t
t
CN
CF, dCH II
dCH I, dNH
CH
1203 m
1089 w
s
2
1200 w
1162 w
1195 w
1158 w
1106 w
1079 s
dCH II
dCH I
dCH II
dCH I
dCH I,
dCH II
dCH I
dCH II
c
c
c
c
q
NH
1119 w
1092 w
1078 m
1019 w
tCN
1015 w
992 s
0.06
1.36
1.37
1.21
0.17
2.72
19.27
6.31
15.15
69.40
8.16
7.50
9.16
CH I
968 w
940 m
CH II
CH II
CH II
946 w
934 w
13.12
11.68
8.57
15.81
1.91
20.22
0.26
6.97
12.65
1.64
1.20
26.93
0.65
48.24
0.21
934 s
894 s
qCH
2
c
c
CH I,
CH I
tCC
871 m
833 s
869 w
844 m
dNO
CH II
Ring breath II
2
c
847 s
744 s
0.92
c
c
c
x
x
c
c
c
CH I
CH II
NH
NH,
NO
Ph I
Ph II
Ph I
38.13
67.84
0.43
35.22
2.57
18.87
20.17
14.66
0.11
3.22
11.47
3.98
3.92
13.45
4.44
814 s
778 m
813 s
768 w
cCH II
744 s
722 w
710 w
759 w
718 w
2
3.42
15.18
51.53
29.74
0.23
0.86
13.85
2.44
6.28
15.79
7.68
11.54
10.93
3.25
6.60
680 w
638 w
669 w
605 w
555 m
Ring breath I
dPh II, dC@O
11.63
11.64
14.66
3.52
8.19
15.41
8.69
8.64
12.53
0.22
1.34
21.88
86.91
621 w
c
OH
dPh(X) II
Ph I(X)
dPh I
Ph II,
dPh II
570 w
542 m
c
c
qNO
2
524 w
484 w
10.87
4.57
6.30
1.13
3.35
499 w
475 w
445 w
417 w
c
c
c
c
Ph II, c
Ph I(X)
Ph II
Ph II
C@O
423 w
9.99
5.50
16.27
389 w
377 m
dPh II
dPh I
11.48
(
continued on next page)

2
28
Y.S. Mary et al. / Journal of Molecular Structure 994 (2011) 223–231
Table 1 (continued)
⁄
⁄
⁄
ꢀ1
ꢀ1
(Raman) (cm
ꢀ1
HF/6-31G
B3PW91/6-31G
B3LYP/6-31G
t(IR) (cm
)
t
)
t
(Raman) (cm ) SERS
Assignments
(cm 1
ꢀ
)
IR intensity
t
(cm
ꢀ1
)
IR intensity
t
(cm
ꢀ1
)
IR intensity
t
357
356
300
284
269
262
221
217
158
142
103
1.30
1.03
0.93
1.38
191.07
9.33
8.50
4.84
4.11
1.39
2.19
360
340
324
300
295
241
212
161
137
131
82
0.77
5.71
0.22
0.95
0.57
1.10
0.29
1.68
1.97
2.46
0.55
356
353
330
297
285
260
218
215
155
142
101
32.44
1.05
134.08
0.68
0.24
2.71
3.96
1.73
2.43
1.04
1.38
356 w
364 m
cPh I
dPh II
dCF(X)II
c
c
CF(X)II
CC(X)II
289 w
252 w
221 m
dCO(X)I
CO(X)I
dCN(X)II
c
c
c
c
CN(X)I
CN(X) I
CC(X)II
146 w
98 s
t
– stretching, d – in-plane bending, c – out-of-plane bending, s – torsion, s – strong, m – medium, w – weak, v – very, br – broad; Ph I and Ph II – tri and para substituted
phenyl rings; X – substituent sensitive; subscript: as – asymmetric, s – symmetric.
ents, the bands tend to shift to some what lower wavenumbers,
and the greater the number of substituents on the ring, the broader
of the absorption regions [38]. In the case of C@O substitution, the
4.2. SERS spectrum
SERS has been applied as a powerful technique for innovative
and extensive analytical applications in surface science, electro-
chemistry, biology and materials research [52–54]. SERS is already
regarded as a valuable method because of its high sensitivity,
which enables the detection and spectroscopic study of even single
molecules [55]. The vibrational information contained in the SERS
spectrum provide the molecular specificity required to character-
ize the adsorbate–surface interactions, specifically, the orientation
of the adsorbed species on the metal surface. The relative intensi-
ties from the SERS spectra are expected to differ significantly from
normal Raman spectra owing to specific surface selection rules
[56]. The surface selection rule suggest that for a molecule ad-
sorbed flat on the silver surface, its out-of-plane vibrational modes
will be more enhanced when compared with its in-plane vibra-
tional modes and vice versa when it is adsorbed perpendicular to
the surface [56,57]. It is further seen that vibrations involving
atoms that are close to the silver surface will be more enhanced
when the wavenumber difference between the Raman bands in
ꢀ1
band near 1490 cm can be very weak [38]. The fifth ring stretch-
ꢀ1
ing vibration is active near 1315 ± 65 cm , a region that overlaps
strongly with that of the CH in-plane deformation [38]. The sixth
ring stretching vibration, the ring breathing mode appears as a
ꢀ1
weak band near 1000 cm in mono, 1,3-di- and 1,3,5-tri-substi-
tuted benzenes. In the otherwise substituted benzenes, however,
this vibration is substituent sensitive and difficult to distinguish
from other modes. The ring breathing mode for the para substi-
tuted benzenes with entirely different substitutents [41] has been
reported to be strongly IR active with typical bands in the interval
ꢀ
1
7
80–840 cm . For the title compound, this is confirmed by the
ꢀ1
band in the IR spectrum at 833 and at 844 cm in Raman spec-
trum, which finds support from the computational results. The ring
breathing mode of para-substituted benzenes are reported at 804
ꢀ1
ꢀ1
and 792 cm experimentally and at 782 and 795 cm theoreti-
cally [49,50]. In asymmetric tri-substituted benzenes, when all
the three substituents are light, the wavenumber interval of the
ꢀ1
ꢀ1
breathing mode [41] is between 500 and 600 cm . When all the
three substituents are heavy, the wavenumber appears above
100 cm . In the case of mixed substituents, the wavenumber is
expected [41] to appear between 600 and 750 cm . For the title
compound the phenyl ring I breathing mode is observed at
72 cm theoretically.
the normal and SERS spectrum is not more than 5 cm , the molec-
ular plane is expected to be perpendicular to the silver surface [58].
In the SERS spectrum of the title compound the aromatic CH
stretching vibration are absent, which means that the phenyl ring
may be somewhat flat on the silver surface [58,59]. It has also been
documented in literature [60] that when a benzene ring moiety
interacts directly with a metal surface, the ring breathing mode
ꢀ1
1
ꢀ1
ꢀ1
6
For para-substituted benzenes, the dCH modes are seen in the
ꢀ
1
ꢀ1
range 995–1315 cm
and for tri substituted benzenes these
is red shifted by 10 cm along with substantial band broadening
in the SERS spectrum. In the present case, the ring breathing modes
ꢀ1
modes are in the range [38] 1290–1050 cm . In the present case,
CH modes are observed in the range 1019–1270 cm in the IR
spectrum and in the range 1079–1268 cm in the Raman spec-
trum. The B3LYP calculations give these modes in the range
013–1309 cm and some of the bands are not pure but contain
ꢀ1
ꢀ1
d
of ring I and II are present in the SERS spectrum at 669 cm and
ꢀ1
ꢀ1
847 cm . Neither a substantial red shift nor a significant band
broadening was observed in the SERS spectrum, for the Phenyl ring
II where as, for the phenyl ring I, the ring breathing mode is red
ꢀ1
1
ꢀ
1
significant contribution from other modes. The out-of-plane CH
shifted by 11 cm imply that the probability of a direct ring
p-
ꢀ1
deformations [38] are observed between 700 and 1000 cm
.
orbital of phenyl ring I to metal surface is present. The presence
ꢀ1
Generally the CH out-of-plane deformations with the highest
wavenumbers are weaker than those absorbing at lower wave-
of CH
trum indicates the closeness of CH
face and interaction of the silver surface with this moiety. This is
2
modes 2975, 2928, 1460, 1203, 934 cm in the SERS spec-
2
AC@O group with metal sur-
ꢀ1
numbers. The strong
cCH band occurring at 840 ± 50 cm , is typ-
ꢀ1
ical for para substituted benzenes [38]. For the title compound, a
supported by the presence of
spectrum
The in-plane bending modes dCH of the phenyl ring I are not ob-
served in the SERS spectrum whereas for phenyl ring II, the dCH
tC@O band at 1651 cm in the SERS
ꢀ1
band is observed at 814 cm in the IR spectrum. Again according
to literature [35,38] a lower CH absorbs in the neighborhood of
20 ± 45 cm , but is much weaker or infrared inactive. The DFT
c
ꢀ1
8
ꢀ
1
ꢀ1
calculation give a
c
CH at 763 cm and no band is experimentally
modes are observed at 1089 and 1015 cm which are absent in
observed for this mode. In the case of tri-substitued benzenes, two
the normal Raman spectrum. The presence of these modes suggest
that the benzene ring II is oriented tilted to the silver surface
[56,57]. The phenyl ring stretching vibrations are observed at
ꢀ1
c
CH bands are observed at 890 ± 50 and 815 ± 45 cm in the IR
ꢀ1
spectrum. The bands observed at 871 (IR) 909 cm
assigned to this modes. The IR bands in the 2855–1887 cm
(DFT) are
ꢀ1
ꢀ1
ꢀ1
1606, 1490, 1312 cm for Ph I and at 1423 cm for PhII in the
SERS spectrum. The out-of-plane CH deformations of phenyl ring
region and their large broadening support the intra molecular
hydrogen bonding between the C@O and OH groups [51].
ꢀ1
I are present in the SERS spectrum at 992, 894 cm which are ab-

Y.S. Mary et al. / Journal of Molecular Structure 994 (2011) 223–231
229
sent in the normal Raman spectrum whereas
sent in the SERS spectrum of the title compound.
c
CH of Ph II are ab-
to literature [8,10,14,71] the changes in bond lengths in C@O and
CAN are consistent with the following interpretation: that is,
hydrogen bond decreases the double bond character of C@O bond
and increases the double bond character of CAN bond. For 2-nitro-
In the SERS spectrum of 2-amino-5-nitropyridine [61] the sym-
2
metric NO stretching mode corresponds to the most intense band,
which appears broad and significantly down shifted from
N-(4-nitrophenyl)benzamide [68] C24AO25 = 1.2132, N30AO32
1.2292, 30AO31 = 1.2252, 26AC24 = 1.3612, 26AC11 = 1.4042
and 30AC17 = 1.4632 Å. The B3LYP calculations give the
corresponding values as 1.2478, 1.2658, 1.2687, 1.3801, 1.3998
and 1.4556 Å for the title compound. For the benzamide
moiety of the title compound the calculated values of the bond
=
ꢀ1
ꢀ1
1
344 cm to 1326 cm suggesting binding to silver through the
N
N
N
lone pairs of the oxygen atom. Carrasco et al. [62] observed the
N
ꢀ
1
NO
2
stretch in the SERS spectrum at ꢁ1500 cm with medium
intensity, which demonstrated the importance of nitro group in
regard to the interaction with the metal surface. Further, they ob-
served the enhancement of
tPh modes, revealing that the molecule
angles C24AN26AC11, C13AC11AN26, O25AC24AN26, O
2
AC24AC21,
is oriented perpendicular to the metal surface, whereas the changes
that occur in the nitro group indicate that the interaction occurs
through oxygen atoms of the nitro moiety. The interaction induces
N
26AC24AC21 are 127.9, 115.9, 123.7, 120.7, 115.5° whereas the re-
ported values of similar derivatives are 124.7, 116.6, 123.1, 118.7,
118.3°[70] and 122.7, 120.3, 1221., 122.7, 115.2°[72]. In the
present case, at C24 position the angles C21AC24AO25 = 120.7°,
a p-electronic redistribution primarily around both the nitro group
and the aromatic portion in the vicinity of the substitution site. Also
Gao and Weaver [63] observed broadening and a downshift of the
corresponding band of nitrobenzene adsorbed on gold via nitro
group. For the title compound the symmetric stretching mode of
C
26AC24AO25 = 123.7° and C26AC24AC21 = 115.5° and this asymme-
try of exocyclic angles reveals the interaction between O25 and H23
.
Also at C11 position the angles C12AC11AN26 is increased by
5.1° and C13AC11AN26 is reduced by 4.1° from 120° and this asym-
metry reveals the interaction between the amide moiety and the
phenyl ring I. The CC bond lengths in the phenyl ring I lie between
1.3837–1.4181 Å, whereas for the phenyl ring II, the range is
1.3895–1.4084 Å. The CH bond lengths lie between 1.0794 and
1.0830 Å for phenyl ring I and 1.0830 and 1.0860 Å for phenyl
ring II. The CC bond length of benzene [73] is 1.3993 Å and
benzaldehyde [74] is 1.3973 Å. The torsion angles around
2
NO which is absent in the normal Raman spectrum appears at
ꢀ
1
1
2
376 cm in the SERS spectrum. Interaction through the NO group
ꢀ1
was also supported by the presence of mode at 744 cm
.
Keeping in mind the behavior observed for molecules contain-
ing -system adsorbed flat on the metal surface [57,63–65], a
p
purely parallel orientation of the molecular skeleton with respect
to the surface appears unlikely in the light of the following argu-
ments. The ring breathing modes of phenyl ring II appears as a
the benzamide group in the present case C14AC12AC11AN26
ꢀ179.9, 26AC11AC13AC16 = 179.9, 25AC24AC21 = ꢀ153.7,
26AC24AC21AC = 28.8 where as the corresponding reported val-
=
ꢀ1
strong band at 847 cm without any significant band broadening
or red shift where as for phenyl ring I, a weak SERS band is ob-
N
O
A
3
N
3
ꢀ1
ꢀ1
served at 669 cm
dCH modes of Ph I are absent in the SERS spectrum while for Ph
II dCH modes are present in the SERS spectrum. The CH modes
with a red shift of 11 cm . Also in-plane
ues are 178.5, ꢀ178.9, 161.1163.8 [69] and ꢀ178.3, ꢀ179.8,
ꢀ158.2, 22.1 [72]. The strong steric repulsion between phenyl ring
II and the amide group is confirmed by the non-planarity of the
benzamide, where the amide group is turned by ꢀ153.7
c
of Ph I are present in the SERS spectrum while that of Ph II are ab-
sent. The substituent sensitive modes of Phenyl ring I are in pres-
3 2 3
(C AC21AC24AO25), and 77.3 (C AC AC21AC24) with respect to
ꢀ1
ent in the SERS spectrum at 555 and 364 cm . The
t
Ph modes of
the benzene ring [14]. That is, it may be due to the repulsion
between hydrogen atoms H8 and H23 as reported in literature
[13,14,16,73].
Ph I and Ph II are also present in the SERS spectrum. The appear-
ance of these modes support that both the ring are tilted with re-
spect to the metal surface [58,59,66].
3
The values of angles C AC21AC24 116.6 and C21AC24AO25 120.7°
of the benzamide group of the title compound are smaller than
those of benzaldehyde (120.6 and 123.6°) [74]. These differences
are ascribed to the steric repulsion between H23 and H22 atoms.
The C21AC24 bond length 1.5340 is larger than the corresponding
length of benzaldehyde [74] (1.4794 Å) by about 0.0546 Å. The
4
.3. Geometrical parameters and first hyperpolarizability
To best of our knowledge, no X-ray crystallographic data of this
molecule have yet been reported. However, the theoretical results
obtained are almost comparable with the reported structural
parameters of similar derivatives. The carbon–oxygen (phenolate)
C
24AO25 bond length 1.2478 Å given by B3LYP calculation is great-
er than that of a similar benzamide by 0.0025 Å, where the
C24AN26 bond length 1.3801 is larger by 0.0191 Å [16]. The corre-
C
13AO28 distance is 1.3940 Å where as the average CO bond length
is 1.362 for phenols [67]. B3LYP calculations give shortening of the
angles C14AC17AN30 by 0.2°, C16AC17AN30 by 1.5° at C17 position,
sponding difference for acetamide are 0.03 and 0.04 Å and those for
formamide are 0.03 and 0.05. The changes found for benzamide are
similar to those for formamide [6] and acetamide [7,8,11]. The
C
1
17AN30AO32 by 1.7°, C17AN30AO31 by 2° at N30 position from
20°. This reduction in angles reveal the hydrogen bonding be-
3
C AC21 bond length 1.5149 Å is also shorter than reported values
tween H18 and H19 atoms., which is evident from the enlargement
in the angles C14AC17AC16 by 1.8 and O31AN30AO32 by 3.6° from
of similar molecules [16], although the difference is not large as
the difference in the C@O and CAN bonds. This shortening indi-
cates that the conjugation between amide group and phenyl
groups increases in the crystal.
1
20°. The bond angles of the NO
2
group of the title compound
O
32AN30AO31 = 123.6°, O32AN30AC17 = 118.3° and O31AN30AC17
=
1
1
18.0° which are in agreement with the values 123.5, 118.7 and
17.9° given by Saeed et al. [68].
For benzamide derivatives, Nishikawa et al. [20] reported the
bond lengths
C
21AC24 = 1.489–1.505,
C24AO25 = 1.211–1.226,
For Benzamide derivatives, Noveron et al. [69] reported the
C24AN26 = 1.37–1.388, N26AH27 = 1.01, N26AC11 = 1.396–1.411 Å,
bond lengths C11AN26, C24AO25, C24AN26, C24AC21 and N26AH27
as 1.3953, 1.2253, 1.3703, 1.4943 and 0.733 Å, where as the corre-
sponding values for the title compound are, 1.3998, 1.2478, 1.3801,
the bond angles,
C
21AC24AO25 = 121.3–124.7,
O
C
25AC24AN26
24AN26AC11
=
=
123.0–123.8,
121.0–129.0,
C24AN26AH27 = 115.9–116.0,
H
27AN26AC11 = 114.7 and the dihedral angles,
25AC24AN26AC11 = 0.6–2.8,
27AN26AC11AC12 = ꢀ178.0,
1
.5340 and 1.0144 Å. For N-(2-pyridyl)benzamide complexes [70]
the bond lengths C24AO25 = 1.2445, C24AN26 = 1.3646, C11AN26
.4156 Å and for the title compounds the corresponding values
are 1.2478, 1.3801 and 1.3998 Å. The C@O and C@N bond lengths
16] in benzamide, acetamide and formamide are respectively,
.2253, 1.2203, 1.2123 and 1.3801, 1.3804, 1.3683 Å. According
C
O
3
AC21AC24AO25 = ꢀ1.1–23.92,
O
H
=
25AC24AN26AH27 = 170.5–171.6,
1
C24AN26AC11AC12 = 4.5–49.1°. In the present case, the correspond-
ing calculated values are 1.5340, 1.2478, 1.3801, 1.0144, 1.3998 Å
(bond lengths), 120.7°, 123.7°, 117.7°, 127.9°, 114.5° (bond angles)
and ꢀ153.7°, ꢀ0.5°, 178.1°, ꢀ178.7°, ꢀ0.1° (dihedral angles). Zhou
[
1

2
30
Y.S. Mary et al. / Journal of Molecular Structure 994 (2011) 223–231
Fig. 8. Correlation graph.
et al. [75] reported
26AC11 = 1.3443 (XRD) 1.414 (DFT), N26AC24 = 1.3193 (XRD),
.399 (DFT), 21AC24AO25 = 115.1 (XRD), 118.0 (DFT),
21AC24AN26 = 115.2 (XRD), 123.9° (DFT) for a similar benzamide
O
25AC24 = 1.2723° (XRD), 1.249 (DFT),
[78]. We conclude that the title compound is an attractive object
for future studies of nonlinear optical properties.
N
1
C
C
In order to investigate the performance and vibrational wave-
numbers of the title compound root mean square (RMS) value
and correlation coefficients between calculated and observed
wavenumbers were calculated (Fig. 8). RMS values of wavenum-
bers were evaluated using the following expression [3].
derivative, which is in agreement with our calculated values,
1
.2478°, 1.3998°, 1.3801°, 120.7° and 115.5°.
For 2-hydroxy-benzamides, Kawski et al. [4] reported the bond
lengths, O28AC13 = 1.3634, O25AC24 = 1.2553, N26AC24 = 1.3334,
AC21 = 1.5044, N26AC11 = 1.4634 Å whereas the corresponding
calculated values for the title compound are 1.3940, 1.2478,
.3801, 1.5149, 1.3998 Å. In the present case, the bond angles,
vffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
u
n
u
t
X
C
3
1
exp
2
i
calc
i
RMS ¼
ðt
ꢀ
t
Þ
n ꢀ 1
i
1
O
O
28AC13AC11 = 114.9, O28AC13AC16 = 123.7, C11AC13AC16 = 121.4,
25AC24AN26 = 123.7, O25AC24AC21 = 120.7, N26AC24AC21 = 115.5,
The RMS error of the observed Raman bands and IR bands are
found to be 32.12, 35.01 for HF, 24.69, 26.09 for B3PW91 and
12.03, 14.01 for B3LYP methods, respectively. The small differences
between experimental and calculated vibrational modes are ob-
served. It must be due to the fact that hydrogen bond vibrations
present in the crystal lead to strong perturbation of the infrared
wavenumbers and intensities of many other modes. Also, we state
that experimental results belong to solid phase and theoretical cal-
culations belong to gaseous phase.
C
24AN26AC11 = 127.9, N26AC11AC13 = 115.9 whereas the reported
values are 117.8, 121.7, 120.5, 121.1, 119.7, 119.1, 124.6, 112.1°[4].
Analysis of organic molecules having conjugated -electron
p
systems and large hyperpolarizability using infrared and Raman
spectroscopy has evolved as a subject of research [76]. The poten-
tial application of the title compound in the field of nonlinear op-
tics demands the investigation of its structural and bonding
features contributing to the hyperpolarizability enhancement, by
analyzing the vibrational modes using the IR and Raman spectrum.
5
. Conclusion
ꢀ1
The ring stretching bands at 1626, 1588, 1506, 1339,833 cm ob-
served in IR have their counterparts in the Raman spectrum at
The FT-IR, FT-Raman and SERS spectra of 4-fluoro-N-(2-hydroxy-
-nitrophenyl) phenylacetamide were studied. The molecular
geometry and the wavenumbers were calculated using different
levels of theory. The observed wavenumbers are found to be in
agreement with the calculated (B3LYP) values. The presence of
ꢀ1
1
606, 1586, 1506, 1335, 844 cm , respectively and their relative
intensities in IR and Raman spectrum are comparable. The first
hyperpolarizability (b ) of this novel molecular system is calcu-
4
0
lated using DFT method, based on the finite field approach. In the
presence of an applied electric field, the energy of a system is a
function of the electric field. First hyperpolarizability is a third rank
tensor that can be described by a 3 ꢂ 3 ꢂ 3 matrix. The 27 compo-
nents of the 3D matrix can be reduced to 10 components due to the
Kleinman symmetry [77]. The components of b are defined as the
coefficients in the Taylor series expansion of the energy in the
external electric field. When the electric field is weak and homoge-
neous, this expansion becomes
2 2
CH and NO modes in the SERS spectrum indicates the nearness
of these groups to the metal surface, which affects the orientation
and metal molecule interaction. The presence of phenyl ring defor-
mation bands, show a tilted orientation of the molecule with respect
to the silver surface. The red shift of the NH stretching wavenumber
in the IR spectrum from the calculated wavenumber indicates the
weakening of NH bond resulting in proton transfer to the neighbor-
ing oxygen atom. The geometrical parameters of the title compound
are in agreement with the reported similar derivatives.
X
X
X
1
6
i
i
j
i j k
E ¼ E
0
ꢀ
liF ꢀ 1
a
ijF F ꢀ
b F F F
ijk
2
i
ij
ijk
X
Appendix A. Supplementary material
1
4
i
j k l
ꢀ 2
cijklF F F F þ :::
ijkl
Supplementary data associated with this article can be found, in
the online version, at doi:10.1016/j.molstruc.2011.03.022.
i
where E
the origin,l , aij, bijk and c
0
is the energy of the unperturbed molecule, F is the field at
ijkl are the components of dipole moment,
i
polarizability, the first hyper polarizabilities, and second hyperpo-
larizibilities, respectively. The calculated first hyperpolarizability
References
ꢀ30
[1] E.A. Sener, K.K. Bingol, I. Oren, O.T. Arpaci, I. Yalcin, N. Altanlar, Farmaco 55
of the title compound is 9.432 ꢂ 10
esu, which is comparable
(
2000) 469.
with the reported values of similar derivatives [72] which is 42
times the corresponding value for the standard NLO material urea
[
2] E. Aki-Sener, K.K. Bingol, O. Temiz-Arpaci, I. Yalcin, N. Altanlar, Farmaco 57
(2002) 451.

Y.S. Mary et al. / Journal of Molecular Structure 994 (2011) 223–231
231
[
[
3] L. Ushakumari, H.T. Varghese, C.Y. Panicker, T. Ertan, I. Yildiz, J. Raman
Spectrosc. 39 (2008) 1832.
4] P. Kawski, A. Kochel, M.G. Perevozkina, A. Filarowski, J. Mol. Struct. 790 (2006)
[37] P.L. Anto, C.Y. Panicker, H.T. Varghese, D. Philip, O. Temiz-Arpaci, B.T. Gulbas, I.
Yildiz, Spectrochim. Acta 67A (2007) 744.
[38] N.P.G. Roeges, A Guide to the Complete Interpretation of Infrared Spectra of
Organic Structures, Wiley, New York, 1994.
6
5.
[
[
[
[
[
5] H. Arslan, U. Florke, N. Kulcu, G. Binzet, Spectrochim. Acta 68A (2007) 1347.
6] M. Kitano, K. Kuchitsu, Bull. Chem. Soc. Jpn. 47 (1974) 67.
7] M. Kitano, K. Kuchitsu, Bull. Chem. Soc. Jpn. 46 (1973) 3048.
8] E.D. Stevens, Acta Cryst. 34B (1978) 544.
[39] M. Barthes, G. De Nunzio, G. Riber, Synth. Met. 76 (1996) 337.
[40] A.S. El-Shahawy, S.M. Ahmed, N.K. Sayed, Spectrochim. Acta 66A (2007) 143.
[41] G. Varsanyi, Assignments of Vibrational Spectra of Seven Hundred Benzene
Derivatives, Wiley, New York, 1974.
[42] G. Varsanyi, P. Sohar, Acta Chim. Acad. Sci. Hung. 76 (1973) 243.
[43] A. Perjessy, D. Rasala, P. Tomasik, R. Gawinecki, Collect. Czech. Chem.
Commun. 50 (1985) 244.
9] J. Ladell, B. Post, Acta Cryst. 7 (1954) 559.
[
[
10] T. Ottersen, Acta Chem. Scand. 29A (1975) 939.
11] G.A. Jeffrey, J.R. Ruble, R.K. McMullan, D.F. DeFrees, J.S. Binkley, J.A. Pople, Acta
Cryst. 36B (1980) 2292.
[44] J.F. Brown Jr., J. Am. Chem. Soc. 77 (1955) 6341.
[
[
[
[
[
12] W.A. Denne, R.W.H. Small, Acta Cryst. 27B (1971) 1094.
13] C.C.F. Blake, R.W.H. Small, Acta Cryst. 28B (1972) 2201.
14] Q. Gao, G.A. Jeffrey, J.R. Ruble, R.K. McMullan, Acta Cryst. 47B (1991) 742.
15] Y.S. Choi, J. Kim, J. Park, J. Yu, C. Yoon, Spectrochim. Acta 52A (1996) 1779.
16] H. Takeuchi, M. Sato, T. Tsuji, H. Takashima, T. Egawa, S. Konaka, J. Mol. Struct.
[45] J.H.S. Green, V. Kynanston, A.S. Lindsery, Spectrochim. Acta 17 (1961) 486.
[46] O. Exner, S. Kovac, E. Sokaniova, Collect. Czech. Chem. Commun. 37 (1972)
2156.
[47] D.S.R. Rao, G. Thyagarajan, Indian J. Pure Appl. Phys. 16 (1978) 941.
[48] N. Sundaraganesan, S. Ayyappan, H. Umamaheswari, B.D. Joshua, Spectrochim.
Acta 66A (2007) 17.
4
85–486 (1999) 175.
[
[
[
[
17] G. Biagi, I. Giorgi, O. Livi, A. Nardi, V. Calderone, A. Martelli, E. Martinotti, O.L.
Salerni, Eur. J. Med. Chem. 39 (2004) 491.
18] H.S. Rho, H.S. Baek, S.M. Ahn, J.W. Yoo, D.H. Kim, H.G. Kim, Bioorg. Med. Chem.
Lett. 19 (2009) 1532.
[49] Y.S. Mary, H.T. Varghese, C.Y. Panicker, T. Ertan, I. Yildiz, O. Temiz-Arpaci,
Spectrochim. Acta 71 (2008) 566.
[50] A.R. Ambujakshan, V.S. Madhavan, H.T. Varghese, C.Y. Panicker, O. Temiz-
Arpaci, B.T. Gulbas, I. Yildiz, Spectrochim. Acta 69A (2007) 782.
[51] D. Philip, A. John, C.Y. Panicker, H.T. Varghese, Spectrochim. Acta 57 (2001)
1561.
[52] W.B. Cai, T. Amano, M. Osawa, J. Electroanal. Chem. 500 (2001) 147.
[53] K. Kneipp, H. Kneipp, I. Itzkan, R.R. Dasari, M.S. Feld, Chem. Rev. 99 (1999)
2957.
[54] V. Oklejas, C. Sjostrom, J.M. Harris, J. Am. Chem. Soc. 124 (2002) 2408.
[55] S. Nie, S.R. Emory, Science 275 (1997) 1102.
19] H.A. Dabbagh, A. Teimouri, A.N. Chermahini, M. Shahraki, Spectrochim. Acta
6
9A (2008) 449.
20] J. Nishikawa, T. Imase, M. Koike, K. Fukuda, M. Tokita, J. Watanabe, S.
Kawauchi, J. Mol. Struct. 741 (2005) 221.
21] Y.R. Shen, The Principles of Nonlinear Optics, Wiley, New York, 1984.
22] P.V. Kolinsky, Opt. Eng. 31 (1992) 1676.
23] D.F. Eaton, Science 253 (1991) 281.
24] C.R. Moylan, R.J. Twieg, V.Y. Lee, S.A. Swanson, K.M. Betterton, R.D. Miller, J.
Am. Chem. Soc. 115 (1993) 12599.
[
[
[
[
[56] J.A. Creighton, Spectroscopy of Surfaces – Advances in Spectroscopy, vol. 16,
Wiley, New York, 1988, p. 37 (Chapter 2).
[
25] S. Gilmour, R.A. Montigomery, S.R. Marder, L.T. Cheng, A.K.Y. Je, Y. Cai, J.W.
Perry, L.R. Dalton, Chem. Mater. 6 (1994) 1603.
26] C. Ravikumar, I.H. Joe, V.S. Jayakumar, Chem. Phys. Lett. 460 (2008) 552.
27] T. Ertan, I. Yildiz, S. Ozkan, O.T. Arpaci, F. Kaynak, I. Yalcin, E.A. Sener, U.
Abbasoglu, Bioorg. Med. Chem. 15 (2007) 2032.
[57] X. Gao, J.P. Davies, M.J. Weaver, J. Phys. Chem. A 94 (1990) 6858.
[58] G. Levi, J. Patigny, J.P. Massault, J. Aubard, in: Thirteenth International
Conference on Raman Spectroscopy, Wurzburg, 1992, p. 652.
[59] J.S. Suh, M. Moskovits, J. Am. Chem. Soc. 108 (1986) 4711.
[60] P. Cao, M.J. Weaver, J. Phys. Chem. A 93 (1989) 6205.
[61] M.M. Maurizio, Vib. Spectrosc. 29 (2002) 229.
[62] E.A. Carrasco, F.M. Compos-Vallette, P. Leyton, G. Diaz, R.E. Clavijo, J.V. Garcia-
Ramos, N. Inostroza, C. Domingo, S. Sanchez-Cortes, R. Koch, J. Phys. Chem. 107
(2003) 9611.
[63] P. Gao, M.J. Weaver, J. Phys. Chem. 89 (1985) 5040.
[64] M.L. Patterson, M.J. Weaver, J. Phys. Chem. 89 (1985) 5046.
[65] Y.J. Kwon, D.H. Son, S.I. Ahn, M.S. Kim, S. Kim, J. Phys. Chem. 98 (1994) 8481.
[66] J.A. Creighton, Surf. Sci. 124 (1983) 209.
[67] F.H. Allen, O. Kennard, D.G. Watson, L. Brammer, A.G. Orpen, R. Taylor, J. Chem.
Soc. Perkin Trans. 2 (1987) S1.
[
[
[
[
28] P.C. Lee, D.J. Meisel, J. Phys. Chem. 86 (1982) 3391.
29] M.J. Frisch, G.W. Trucks, H.B. Schlegel, G.E. Scuseria, M.A. Robb, J.R. Cheeseman,
J.A. Montgomery, Jr., T. Vreven, K.N. Kudin, J.C. Burant, J.M. Millam, S.S. Iyengar,
J. Tomasi, V. Barone, B. Mennucci, M. Cossi, G. Scalmani, N. Rega, G.A.
Petersson, H. Nakatsuji, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J. Hasegawa,
M. Ishida, T. Nakajima, Y. Honda, O. Kitao, H. Nakai, M. Klene, X. Li, J.E. Knox,
H.P. Hratchian, J.B. Cross, C. Adamo, J. Jaramillo, R. Gomperts, R.E. Stratmann,
O. Yazyev, A.J. Austin, R. Cammi, C. Pomelli, J.W. Ochterski, P.Y. Ayala, K.
Morokuma, G.A. Voth, P. Salvador, J.J. Dannenberg, V.G. Zakrzewski, S.
Dapprich, A.D. Daniels, M.C. Strain, O. Farkas, D.K. Malick, A.D. Rabuck, K.
Raghavachari, J.B. Foresman, J.V. Ortiz, Q. Cui, A.G. Baboul, S. Clifford, J.
Cioslowski, B.B. Stefanov, G. Liu, A. Liashenko, P. Piskorz, I. Komaromi, R.L.
Martin, D.J. Fox, T. Keith, M.A. Al-Laham, C.Y. Peng, A. Nanayakkara, M.
Challacombe, P.M.W. Gill, B. Johnson, W. Chen, M.W. Wong, C. Gonzalez, J.A.
Pople, Gaussian 03, Revision C.02, Gaussian, Wallingford, 2004.
30] J.B. Foresman, in: E. Frisch (Ed.), Exploring Chemistry with Electronic Structure
Methods: A Guide to Using Gaussian, Gaussian, Pittsburg, PA, 1996.
31] A.P. Scott, L. Radom, J. Phys. Chem. 100 (1996) 16503.
[68] A.S. Saeed, S. Hussain, U. Florke, Turk. J. Chem. 32 (2008) 1.
[69] J.C. Noveron, A.M. Arif, P.J. Stang, Chem. Mater. 15 (2003) 372.
[70] W.H. Sun, W. Zhang, T. Gao, X. Tang, L. Chen, Y. Li, X. Jin, Organomet. Chem. 689
(2004) 917.
[71] J.L. Katz, B. Post, Acta Cryst. 13 (1960) 624.
[
[72] C.Y. Panicker, H.T. Varghese, L. Ushakumari, T. Ertan, I. Yildiz, C.M. Granadeiro,
H.I.S. Nogueira, Y.S. Mary, J. Raman Spectrosc. 41 (2010) 381.
[73] K. Tamagawa, T. Iijima, M. Kimura, J. Mol. Struct. 30 (1976) 243.
[74] K.B. Borizenko, C.W. Bock, I. Hargittai, J. Phys. Chem. 100 (1996) 7426.
[75] W. Zhou, L. Zhu, Y. Zhang, Z. Yu, L. Lu, X. Yang, Vib. Spectrosc. 36 (2004) 73.
[76] M. Tommasini, C. Castiglioni, M. Del Zoppo, G. Zerbi, J. Mol. Struct. 480 (1999)
179.
[
[
[
32] G. Rauhut, P. Pulay, J. Phys. Chem. 99 (1995) 3093.
33] P. Flukiger, H.P. Luthi, S. Portmann, J. Weber, MOLEKEL, 4.3, Swiss Center for
Scientific Computing, Manno, Switzerland, 2000.
34] S. Portmann, H.P. Luthi, Chimia 54 (2000) 766.
35] N.B. Colthup, L.H. Daly, S.E. Wiberly, Inroduction to Infrared and Raman
Spectroscopy, third ed., Academic Press, Boston, 1990.
[
[
[77] D.A. Kleinman, Phys. Rev. 126 (1962) 1977.
[78] M. Adant, I. Dupuis, L. Bredas, Int. J. Quantum. Chem. 56 (2004) 497.
[
36] R. Saxena, L.D. Kaudpal, G.N. Mathur, J. Polym, Sci. Part A: Polym. Chem. 40
(
2002) 3959.