DFT calculations and experimental FT-IR, dispersive-Raman and EPR spectral studies of Copper (II) chloride complex with 3-amino-1-methylbenzene

Article abstract of DOI:10.1016/j.saa.2013.12.068

In this study, we present the synthesis and the characterization of Copper (II) chloride complex with 3-amino-1-methylbenzene (3A1MB). This complex was characterized by vibrational and EPR spectroscopic techniques and elemental analysis. The molecular structure and spectrometry of this complex: Cu(3A1MB)₂Cl₂ and its ligand: 3A1MB have been investigated theoretically by performing DFT/B3LYP calculations. Cu(3A1MB) ₂Cl₂ has been optimized as two conformers and the more stable conformer is determined. The optimized geometries and calculated vibrational frequencies have been evaluated via comparison with experimental values, and the normal modes were assigned on the basis of the percent potential energy distribution (PED). A good agreement between calculated and experimental data is observed.

Full text of DOI:10.1016/j.saa.2013.12.068

Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 123 (2014) 187–193
Contents lists available at ScienceDirect
Spectrochimica Acta Part A: Molecular and
Biomolecular Spectroscopy
journal homepage: www.elsevier.com/locate/saa
DFT calculations and experimental FT-IR, dispersive-Raman
and EPR spectral studies of Copper (II) chloride complex
with 3-amino-1-methylbenzene
⇑
Mustafa Kumru, Tayyibe Bardakçı , Sadik Güner
Department of Physics, Faculty of Arts and Sciences, Fatih University, Istanbul, Turkey
h i g h l i g h t s
g r a p h i c a l a b s t r a c t
ꢀ
The conformational analysis of of
3A1MB and Cu(3A1MB)2Cl2 were
performed.
ꢀ
ꢀ
The more stable conformer of
Cu(3A1MB)2Cl2 was determined.
The calculated DFT results were
compared with experimental
vibrational spectra data.
ꢀ
EPR study was performed for
understanding stereochemistry of the
complex.
a r t i c l e i n f o
a b s t r a c t
Article history:
In this study, we present the synthesis and the characterization of Copper (II) chloride complex with 3-
amino-1-methylbenzene (3A1MB). This complex was characterized by vibrational and EPR spectroscopic
techniques and elemental analysis. The molecular structure and spectrometry of this complex:
Cu(3A1MB)2Cl2 and its ligand: 3A1MB have been investigated theoretically by performing DFT/B3LYP
calculations. Cu(3A1MB)2Cl2 has been optimized as two conformers and the more stable conformer is
determined. The optimized geometries and calculated vibrational frequencies have been evaluated via
comparison with experimental values, and the normal modes were assigned on the basis of the percent
potential energy distribution (PED). A good agreement between calculated and experimental data is
observed.
Received 4 November 2013
Received in revised form 9 December 2013
Accepted 11 December 2013
Available online 17 December 2013
Keywords:
3A1MB
Copper (II) chloride complex
DFT
Vibrational and EPR spectra
Ó 2013 Elsevier B.V. All rights reserved.
Introduction
A number of transition metal complexes of anilines and its
derivatives have been previously reported in various studies
Aniline is an organic compound having the formula C6H7N also
known as phenylamine, aminobenzene or benzamine. Aniline and
its substituted derivatives have been widely used as starting
materials in the formation of many drugs (e.g. paracetamol),
rubber processing chemicals, pesticides, antitoxidans, electro-
optical and many other industrial processes, as well as having great
commercial value, especially in dyestuffs. [1–5]. Taking into
account all these various applications, investigations of their
molecular structures and properties are very important.
[6–13]. However there have been no complete study on theoretical
and molecular structure of these complexes.
The applicability limits of ab initio-HF and DFT/B3LYP methods
on free ligand, 3A1MB (having the formula 3-C7H9N) discussed in
our previous work [8], and DFT/B3LYP method was found more
reliable for vibrational spectral analyses. Since the DFT is the most
appropriate method for predicting aniline geometry and vibrational
spectrum [13–19], in this paper we have performed DFT
calculations for both 3A1MB and Cu(3A1MB)2Cl2 for the first time.
We have also reported FT-IR, FT-FIR, dispersive Raman spectra of
3A1MB and Cu(3A1MB)2Cl2 and the EPR spectral study of
Cu(3A1MB)2Cl2.
⇑
Corresponding author. Tel.: +90 212 8663300x2059; fax: +90 212 8890832.
E-mail address: tayyibe.b@gmail.com (T. Bardakçı).
1386-1425/$ - see front matter Ó 2013 Elsevier B.V. All rights reserved.
http://dx.doi.org/10.1016/j.saa.2013.12.068

188
M. Kumru et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 123 (2014) 187–193
con-stant; k, Boltzmann constant; c, speed of light and T, tempera-
Experimental
ture in Kelvin.
The ligand 3A1MB and CuCl2 were purchased from Aldrich
Chemical Company Inc. and used without further purification.
The complex Cu(3A1MB)2Cl2 was synthesized by mixing ligand
with CuCl2 in the ethanol in the ratio of 2:1 respectively. After mix-
ing these substances, samples were distilled, washed with diethyl-
ether and dried in vacuum. This process was carried out at room
temperature. Composition and purity were determined by elemen-
tal analysis of C, H, N and Cu analysis performed by using atomic
absorption spectroscopy.
The FT-IR spectra of samples between the range of 3500–
530 cmꢁ1 were recorded by Nicolet 6700 Fourier Transform IR (FT-
IR) spectrometer with attenuated total reflectance (ATR) sampling
technique, at room temperature. The FT-FIR spectra of 3A1MB and
Cu(3A1MB)2Cl2 were recorded using polyethylene (PE) pellets over
range 650–50 cmꢁ1 on Nicolet 6700 Fourier Transform IR (FT-IR)
spectrometer. The dispersive-Raman spectra of 3A1MB and
Cu(3A1MB)2Cl2 were recorded with Nicolet DXR Dispersive Raman
Microscope between the range of 3500–10 cmꢁ1 at room tempera-
ture. The laser with the wavelenght of 532 nm was used.
In EPR studies, a conventional X-band (f = 9.78 GHz) Bruker
EMX model EPR spectrometer employing an AC magnetic field
(5 kHz) modulation technique was used to record the first deriva-
tive absorption signal. The sample was placed at the maximum
magnetic field in the cavity. A cylindrical quartz tube was used
to mount the sample in the cavity. The field derivative of micro-
wave power absorption, dP/dH, was registered as a function of
DC magnetic field, H. Digital integration of the EPR curves was per-
formed by Bruker WinEPR software in order to obtain the intensity
of microwave power absorption, P. Operating conditions were
0.2 mW microwave power, 10 Oe modulation amplitude, center
field is 3300 Oe, sweep width is 600 Oe, time constant 81.92 ms
and sweep time 83.89 s with multiple accumulations to enhance
the signal-to-noise ratio.
Results and discussion
Elemental analysis
The general route for the synthesis of Cu(3A1MB)2Cl2 is shown
in Fig. 1 and the theoretical and the experimental C, H, N and Cu
amounts of the complex are given in Table 1. Since the theoretical
and experimental values are close to each other, it can be said that
the complex was obtained as pure.
Molecular geometry
The optimized molecular geometries of free 3A1MB and two
conformers of Cu(3A1MB)2Cl2 in the gas phase (Figs. 2, 3, and
Table 2) obtained in terms of DFT/B3LYP levels with the
6–311G+(d,p) basis set. Since the experimental data on the struc-
ture (bond lengths and bond angles) of 3A1MB are not available
in the literature, the experimental X-ray data of p-methylaniline
that are similar to 3A1MB [24] were given in Table 2. The experi-
mental and calculated geometry parameters are close to each
other. The standard error S and the mean absolute error MAE for
the bond lengths relative to the previous X-ray data are respec-
tively 0.050 and 0.015, and for the bond angles 1.742 and 1.288.
Fig. 1. Synthetic route of Cu(3A1MB)2Cl2.
Table 1
Elemental analysis of the Cu(3A1MB)2Cl2 as percentage.
Computational details
Found (cal.)%
The optimized structures and vibrational frequencies of free
ligand 3A1MB and the two possible conformers of Cu(3A1MB)2Cl2
were calculated at the DFT/B3LYP level with 6–311 + G(d,p) basis
set. All computations were performed on our HP-Linux server
cluster using Gaussian 03 program package [20]. Gaussview pro-
gram [21] was used to get visual animation for the normal modes,
and the verification of the normal modes assignments was per-
formed on the basis of the percent potential energy distribution
(PED).
Comp.
Cu
C
N
H
Cu(3A1MB)2Cl2
(Theoretical)
19.54
(18.22)
48.04
(48.21)
7.78
(8.03)
5.11
(5.21)
Prediction of Raman intensities
The Raman activities (SRa) calculated with Gaussian 03 program,
and converted to relative Raman intensities (IRa) using the follow-
ing expression derived from the Raman scattering intensity theory
[22,23].
4
fð#0 ꢁ #iÞ Si
h
i
Ii ¼
hc#i
#i 1 ꢁ expðꢁ
Þ
kT
where #0 is the laser exciting wavenumber in cmꢁ1 (in this work,
we used the excitation wavenumber #0 = 18796.9924812 cmꢁ1
which corresponds to the wavelength of 532 nm of a Nd:YAG laser),
the vibrational wavenumber of the ith normal mode (cmꢁ1),
,
#
i
while Si is the Raman scattering activity of the normal mode #i, f
(is a constant equal to 10ꢁ12) is a suitably chosen common normal-
ization factor for all peak intensities. In this expression, h, Planck
Fig. 2. The optimized geometry of 3A1MB.

M. Kumru et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 123 (2014) 187–193
189
Fig. 3. The optimized geometry of Cu(3A1MB)2Cl2 (a) conformer 1 (b) conformer 2.
Table 2
Geometry parameters of free 3A1MB and two conformers of Cu(3A1MB)Cl2.
Table 3
Relative energies (kcal/mol) of two conformers of Cu(3A1MB)2Cl2.
Experimentala
DFT – B3LYP/6–311G+(d,p)
Conformer 1
Conformer 2
3A1MB
Conformer 1
Conformer 2
Relative energies (kcal/mol)
Doublet
Quartet
Sextet
0.0
84.7803
157.5676
9.51
93.000
176.8240
Interatomic distance (Å)
C6–C7
C7–C9
C9–C13
C13–C11
C11–C8
C8–C6
C–N
C–CH3
N–H
1.36
1.39
1.40
1.39
1.40
1.39
1.43
1.55
1.02
1.08
1.09
. . .
1.402
1.396
1.399
1.394
1.390
1.402
1.399
1.510
1.009
1.085
1.094
1.674
1.765
. . .
1.394
1.398
1.398
1.394
1.391
1.396
1.442
1.510
1.017
1.084
1.093
1.666
1.765
2.270
2.090
1.395
1.394
1.392
1.401
1.397
1.396
1.436
1.509
1.018
1.085
1.093
1.653
1.766
2.245
2.133
C–H (ring)b
C–H (methyl)b
H. . .H (amino)b
H. . .H (methyl)b
Cu–Cl
. . .
. . .
Cu–N
. . .
. . .
Angle (°)
C8–C6–C7
C6–C7–C9
C7–C9–C13
C9–C13–C11
C13–C11–C8
C11–C8–C6
N–C–C
120.3
120.5
120.5
117.8
121.5
119.2
. . .
118.8
121.5
118.9
119.9
120.9
119.9
120.6
120.5
112.1
111.2
107.6
115.5
. . .
120.6
120.6
118.6
120.6
120.7
118.9
119.7
120.7
110.0
111.2
107.7
111.4
180.0
90.0
120.2
119.3
120.5
120.6
118.6
120.8
119.9
120.7
108.5
111.1
107.8
112.6
101.8
159.1
86.8
C–C–CH3
H–N–H
. . .
113.0
C–C–H (methyl)b
H–C–H (methyl)b
H–N–C
109.5
. . .
Fig. 4. The experimental FT-FIR spectra of 3A1MB (upper) and Cu(3A1MB)2Cl2
(lower).
Cl–Cu–Cl
. . .
N–Cu–Cl36
N–Cu–Cl37
N–Cu–N
. . .
. . .
. . .
. . .
90.0
180.0
. . .
. . .
91.5
the distance between Cu and Cl atoms is 2.270 Å in conformation 1,
whereas 2.245 Å in conformation 2. The distance between Cu and N
atoms is 2.090 Å in conformation 1, and 2.133 Å in conformation 2.
a
Taken from Ref. [24].
Average value.
b
Cu(3A1MB)2Cl2 was optimized as two conformers, conformer 1
and conformer 2 (Fig. 3(a) and (b), respectively). According to DFT
calculations, relative energy values (see Table 3) show that con-
former 1 is significantly more stable than the conformer 2 in all
doublet, quartet and sextet spin states. That is, our complex has
a shape as conformer 1, and it must have one unpaired electron,
supporting our previous study [25]. Since the relative energy val-
ues in quartet and sextet spin states greater than the doublet,
our calculations ensure that this complex cannot have 3 or 5 un-
paired electrons.
According to the DFT calculations C–N bond length increased
from 1.399 Å to 1.442 Å in conformation 1, and to 1.436 Å in
conformation 2 because of coordination. C–C bonds remained un-
changed. In the optimized geometry parameters of Cu(3A1MB)2Cl2,
Vibrational assignment
Vibrational spectroscopy is used in organic chemistry widely for
the identification of functional groups of organic compounds, with
the help of observed and calculated fundamental modes. The ob-
served experimental FT-IR, FT-FIR, and dispersive Raman spectra
of both free ligand 3A1MB and its complex Cu(3A1MB)2Cl2 are
shown in Figs. 3–5, wheras the calculated frequencies and the
proposed assignments are given in Table 4. The assignments were
presented in terms of the percent PED of the internal motions in
the modes. In Table 4,
deformation, , for out-of-plane deformation, and scissoring, rock-
ing, wagging, and torsion vibrations were also observed.
t was used for stretching, b, for in-plane
c

190
M. Kumru et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 123 (2014) 187–193
and 2920 cmꢁ1, and the symmetric C–H vibrations occur at
2859 cmꢁ1. For the Cu(3A1MB)2Cl2, it is very close to the free li-
gand, 2920 cmꢁ1 for asymmetric and 2860 cmꢁ1 for symmetric
vibrations. This shows that methyl group of 3A1MB does not take
part in coordination.
The C–H in plane and out of plane bending vibrations usually
occur in the 1000–1300 cmꢁ1 and 750–100 cmꢁ1 region, and our
assignments approximately coincide with the experimental values
and with the literature [34–38].
In the low frequency region, especially below 600 cmꢁ1, it is
considered that the metal–ligand vibrations ocur [12,13,39].
According to Clark, and Williams [40], in ML2X2 (M is metal, X is
halogen like Cl, Br or I) types of complexes, the Ci site symmetry re-
quires one
some vibrational couplings among Cu–N vibrations may occur,
the spectra of Cu(II) complexes reveals two (Cu–N) bands in the
487–360 cmꢁ1 region [41]. In our study there are also two
(Cu–
N) bands at the 380 cmꢁ1 (16%) and 354 cmꢁ1 (14%), and one
(Cu–Cl) band at 241 cmꢁ1 (17%). That is, the symmetry criteria
t(M–N) and two t(M–X) IR active bands. But, since
t
t
t
Fig. 5. The experimental FT-IR spectra of 3A1MB (upper) and Cu(3A1MB)2Cl2
for determining the number of IR active bands in that region are
not strictly applied to these types of complexes.
(lower).
Theoretical IR and Raman spectra in terms of scaled frequencies
vs. normalized IR and Raman intensities were given in Fig. 6. While
the absolute IR and Raman intensities are shown in Supplementary
data, the normalized values were used in the figures to make their
comparison easier. The calculated and experimental spectra in
terms of IR and Raman intensities are quite consistent.
EPR study
The first-derivative experimental and simulated EPR spectra re-
corded from Cu(3A1MB)2Cl2 compound in solid powder and ethyle
alcohol solution form at room temperature, are shown in the Fig. 7.
Both spectra have similar line shape, which is characteristic for a
crystalline sample containing a paramagnetic ion with a rhombic
local symmetry. In the figure, gx and gy denote the Lande g-values
when the externally applied DC field is in perpendicular, while gz is
in parallel alignment. The g-factors have a trend of gz > gy > gx. All
peaks show the dependence g// > g\ > ge (ge is free electron g-value)
suggesting Cu complexes have approximate axial symmetry Ci
(square planar, or octahedral with tetragonal distortion) with
|B1g > as the ground state of Cu2+ ion [12]. The unpaired electron
is located mainly on the b1g antibonding molecular orbital, which
The calculated frequencies were slightly higher than the exper-
imental values for the normal modes. The reason for these small
discrepancies may be, in the experimental process we recorded
spectra with the solid phase sample, however DFT calculations
were performed with isolated and gas phase molecule. Therefore,
we derived scaling factors on 3A1MB and applied them to
Cu(3A1MB)2Cl2 to approximately account for the computational
errors. For m m
NH; 0.9387, R2 = 0.9809, for CH; 0.9502, R2 = 0.973,
in the range between 1662 and 500 cmꢁ1; 0.9808, R2 = 0.9986, be-
low 500 cmꢁ1, 0.9795, R2 = 0.9987.
is the linear combination of jdx2
> orbital of copper and |hL > -
ꢁy2
Varsanyi [26] assigned N–H strectching vibrations in the region
3500–3300 cmꢁ1 for primary amines. In this present study the
asymmetric and the symmetric vibrations of N–H stretching were
assigned to the bands for free 3A1MB at 3434 and 3354 cmꢁ1 and
for the complex Cu(3A1MB)2Cl2 at 3297 and 3226 cmꢁ1 respec-
tively. This shifting (138–127 cmꢁ1) to the lower frequencies can
be explained as N atom of the amino group coordinates to the me-
tal Cu(II) atom [7–13,27].
ligand orbitals of adequate symmetry [42–44]. The character of
the Cu complexes can be estimated from the g// (or gz) values which
are sensitive to the bond covalency [42]. The centers giving
gz P 2.3 are ionic in their nature and gz < 2.3 have the dominant
covalent character. Our sample has gz ꢂ 2.18 values for solid pow-
der and solution forms respectively. The spectra do not include any
hyperfine peaks. Each part would have 4 peaks due to nuclear spin
(I = 3/2) of copper atom (see Fig. 8).
The NH2 scissoring vibrations are usually observed in the region
1610–1630 cmꢁ1 [7–13,28]. In this study for 3A1MB, NH2 scissor-
ing vibration was observed at 1623 cmꢁ1 and for Cu(3A1MB)2Cl2
it was observed at 1619 cmꢁ1, as in line with the literature. The
experimental values of the NH2 rocking and wagging vibrations
are in good agreement with DFT calculations for both 3A1MB
and Cu(3A1MB)2Cl2.
The anisotropic spin Hamiltonian (assuming no hyperfine inter-
action) describing a rhombic symmetry is
^
^
^
^
Haiso ¼ beðgxBxSx þ gyBySy þ gzBzSzÞ
ð1Þ
where be and S denote Bohr magneton and the electronic spin angu-
lar momentum of magnetic ion, respectively.
In
a randomly oriented crystalline powder system, each
In aromatic amines, C–N stretching vibrations occur in the region
magnetic center has similar properties as it would have in a large
crystal. However, the crystallite symmetry axes of each powder
molecule are subjected to every possible direction of any exter-
nally applied DC magnetic field. That is the overall paramagnetic
system exhibits resonances at all fields, BR varying between per-
pendicular and parallel alignments. For a general orientation of a
single crystallite containing a paramagnetic center, the solution
of the Eq. (1) gives a resonance field as in Refs. [45–47].
1386–1266 cmꢁ1 [29]. In the present study, for 3A1MB a strong IR
band was observed at 1289 cmꢁ1, whereas for Cu(3A1MB)2Cl2
a
weak IR band was observed at 1260 cmꢁ1 and a strong Raman band
was observed at 1256 cmꢁ1 consistent with the literature
[12–13,26,30].
The assignments of C–H stretching vibrations show that the
place of methyl group within a molecule. The asymmetric and
the symmetric C–H symmetric vibrations in methyl group usually
observed between 2990 and 2920 cmꢁ1, whereas the symmetric C–
H vibrations for methyl group are observed at 2900–2840 cmꢁ1
[31–33]. Being in excellent agreement with the literature, in this
study, for 3A1MB the asymmetric C–H vibrations occur at 2948
h
i
BR ¼ hf=geff be ¼ gx2sin2h þ g2ysin2hsin2h þ g2z cos2h ꢁ1=2hf=be
ð2Þ
where, the angles h and Ø describe the orientation of externally ap-
plied field in the g-matrix principal axis system, the symbols h and f

M. Kumru et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 123 (2014) 187–193
191
Table 4
Experimental and calculated wavenumbers of free 3A1MB and Cu(3A1MB)Cl2.
Free ligand
Experimental
IR
Complex
Experimental
IR
Assignments (PED %)
B3LYP
B3LYP
Disp. Ra
Unscaled
Scaled
Disp. Ra
Unscaled
Scaled
3434 s
3354 s
3038 m
3012 m, sh
3444 m, sh
3366 s
3048 s
3664
3567
3180
3165
3154
3143
3100
3074
3020
1662
1646
1627
1527
1507
1491
1471
1412
1348
1339
1313
1192
1191
1131
1092
1058
1018
1009
976
943
876
861
782
746
702
599
558
539
525
448
429
294
286
222
202
3439
3348
3022
3007
2997
2986
2946
2921
2870
1631
1616
1597
1499
1479
1463
1444
1386
1323
1314
1289
1170
1169
1110
1072
1038
999
990
958
926
860
845
768
732
689
588
548
529
515
439
420
288
280
3297 vs
3226 vs
3039 m
3015 w
3568
3482
3194
3180
3172
3164
3105
3079
3025
1650
1639
1631
1530
1507
1489
1474
1416
1351
1343
1274
1197
1182
1165
1113
1061
1029
1021
1009
988
930
3349
3269
3035
3022
3014
3006
2950
2926
2874
1619
1609
1601
1502
1479
1461
1447
1390
1326
1318
1250
1175
1160
1143
1092
1041
1010
1002
990
970
913
891
890
870
776
727
687
649
624
569
565
542
537
516
515
443
405
399
372
347
326
280
279
236
215
206
200
100
100
t
t
NH2 (asym.)
NH2 (sym.)
98
98
98
97
97
99
99
74
t
CH ring
CH ring
CH ring
CH ring
CH3 (asym.)
CH3 (asym.)
CH3 (sym.)
CC; 13 bNH2 (sciss.)
t
t
t
t
t
t
t
2974 m, sh
2948 m, sh
2920 m
2859 w
1623 vs
2976 w
2983 w
2920 s
2858 w, sh
2920 m
2860 w
1619 s
2917 m
1619 s
84 bNH2 (sciss.)
70 CC; 16 bNH2 (rock.); 14 bCH3
1592 vs
1492 vs
1468 s
1592 s
1491 m
1596 s
1496 vs
1468 m
1597 vs
1482 m
t
68 bCCH; 12 bNH2 (rock.); 12 bCH3
57 bCH3; 36 bCCH
90 bCH3 (asym.)
48 bCH3 (asym.); 36 bCCH; 20 bNH2
92 bCH3 (sym.)
1373 m
1312 m, sh
1374 m
1291 s
1128 w
1380 w
1377 m, sh
1344 s
84 bCCH
1326 w
1260 w
1181 w
46 bCCH; 23bNH2 (rock.); 20 bCH3
1289 s
1171 s
1256 s
33 bCCH; 32
87 bCCH; 10bNH2
63 bCCH; 20 CN; 19 t
51 bNH2 (rock.); 35 bCCH
64 bCCH; 18 bNH2; 18 bCH3
t
C-CH3; 27
t
CN
1162 w
t
C-CH3
1081 w
1039 w
1091 vs
996 w
917 m
1052 s
997 s
78
s
CCC-CH3; 22
c
CH
CCC-CH3; 25 bCH3
43 bNH2 (wag.); 33
60 bCH3; 20 bNH2 (wag.); 17 bCCC
33 bNH2 (wag.); 26 bCCH3; 21 bCCC
s
992 m
1000 vs
931 w
926 m
874 m
855 m, sh
776 vs
744 m, sh
691 vs
88
cCH
49 bCCH; 32 tC-CH3; 18 tCN
908
907
78
77
57
65
31
60
c
c
c
c
t
c
CH; 15
CH; 16
CH; 28
CH; 19
CCC; 28
CH; 21
c
c
CN
CN
744 s
886 w
775 s
886
791
741
700
661
636
580
576
552
547
526
525
452
413
407
sCCC-CH3; 15
s
s
CCCN
CCCN
sCCC-CH3; 16
728 m
640 w
t
C-CH3; 20
t
CN
555 w
536 w
520 w
441 m
548 m
510 m
686 s
sCCC-CH3; 19 s
CCCN
73 bNH2 (wag.); 20 bCH
71 bNH2 (wag.); 19 bCH
636 w
566 w
38
38
46
44
50
48
46
s
s
s
s
s
s
CCC-CH3; 34
CCC-CH3; 33
CCCN; 35
CCCN; 38
CCC-CH3; 23
s
s
CCCN; 25
CCCN; 25
c
c
CCC
CCC
297 w
s
s
CCC-CH3; 10bCuN
CCC-CH3; 10bCuN
281 m
212 m
217
198
39
526 w
445 w
s
s
CCCN; 27bCCC
CCCN; 28bCCC
524 s
447 s
CCC-CH3; 24
40
cCH; 31 sCCC-CH3; 23 sCCCN
37 bCCH; 30 bNH2; 29 bC- CH3
37 bCCH; 29 bNH2; 30 bC- CH3
397 w
375 m
370 s
380
55
53
c
s
CCC; 41
CCCN; 23
c
CN; 16
t
CuN
CuN
tCuCl; 11 bCuN
354
333
286
285
241
220
c
CCC; 14 t
328 m
282 m
37 bCCH3; 19 bCN; 18
41 bCCH3; 40 bCN
40 bCCH3; 39 bCN
229 w
34
40
57
59
35
29
36
38
41
35
43
sCCCH; 28sCCCN; 21sCCC-CH3; 17tCuCl
s
CCC-CH3; 40
CCC-CH3; 26
CCC-CH3; 22
s
s
s
CCCH; 16
CCCH; 15
CCCN; 15
s
s
s
s
CCCN
CCCN
CCCH
CCCH
210 w
204 w
210
204
s
s
s
s
152
150
142
137
130
149
147
139
134
127
63
CCCN; 34
CCC-CH3; 32
CCC-CH3; 11bCuCl2; 9bCuN
CCC-CH3; 33 CCCN; 12bCuCl2; 8bCuN
CCCN; 32 CCC-CH3; 8 bCuN
sCCC-CH3; 28
s
CCCN; 14 bCuCl2
sCCCN; 25s
s
s
135 w
124 w
s
s
64
54
s
s
CCC-CH3; 30
CCC-CH3; 31
s
CCCN; 23
s
CCCH; 10 CuCl2
c
53
sCCCN; 18
sCCCH; 8cCuCl2
36
35
87 bCH3
35
34
89 bCH3
29
20
17
12
28
20
17
12
53
42
45
43
s
s
CCC-CH3; 27
CCC-CH3; 36
s
CCCH; 17 CCCN
s
sCCCC; 14 sCCCN
s
s
CCC-CH3; 33
CCC-CH3; 26
s
s
CCCC; 19
CCCC; 22
s
s
CCCN; 8
CCCN; 9
c
c
CuCl2
CuCl2

192
M. Kumru et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 123 (2014) 187–193
Fig. 8. The experimental and theoretical X-band EPR spectra registered from
Cu(3A1MB)2Cl2 complex in powder and ethyle alcohol solution at room
temperature.
Fig. 6. The experimental dispersive Raman spectra of 3A1MB (lower) and
Cu(3A1MB)2Cl2 (upper).
powder systems, the line width and line shape characteristics of
spectra are analyzed in detail by EPR spectroscopy. These curves
reach to their maximum at the resonance field BR. That is, regard-
less of how far it is from the exact resonance field, BR, any center
can give absorption at any field even if it becomes undetectable
experimentally. The contribution from any center to the whole
absorption line at any field depends on the intrinsic line width.
Therefore, an angle dependent equation is used to describe the line
width characteristics [46,50].
represent the Plank’s constant and the microwave frequency,
respectively. For theoretical simulation of experimental spectra,
we need to sum from 0° to 90° both for h and Ø.
The probability of each spin center experiencing a resonant field
value is proportional to Sinh. By adding a weighing factor in Eq. (2),
one can obtain an expression [12,48,49] for absorption intensity of
resonance peaks. As the resonance curves of each individual mag-
netic center have their own intrinsic line shape and width for the
Fig. 7. Comparison of calculated scaled frequencies in cmꢁ1 and normalized IR and Ra intensities of title molecules.

M. Kumru et al. / Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 123 (2014) 187–193
193
Table 5
[9] K. Golcuk, A. Altun, M. Kumru, Spectrochim. Acta Part A 59 (2003) 1841–1847.
[10] A. Altun, K. Golcuk, M. Kumru, Vib. Spectrosc. 31 (2003) 215–225.
[11] K. Golcuk, A. Altun, M. Kumru, J. Mol. Struct. 657 (2003) 385–393.
[12] K. Golcuk, A. Altun, S. Guner, M. Kumru, B. Aktas, Spectrochim. Acta Part A 60
(1–2) (2004) 303–309.
EPR and line width fit parameters of Cu(3A1MB)2Cl2 compound.
Samples
gx
gy
gz
gave
Wx
(Oe)
Wy
(Oe)
Wz
(Oe)
[13] T. Bardakçı, M. Kumru, S. Güner, J. Mol. Struct. 1054–1055 (2013) 76–82.
[14] V. Arjunan, S. Mohan, J. Mol. Struct. 892 (2008) 289–299.
[15] V. Chis, M.M. Venter, N. Leopold, O. Cozar, Vib. Spectrosc. 48 (2008) 210–214.
[16] T. Rajamani, S. Muthu, M. Karabacak, Spectrochim. Acta Part A 108 (2013)
186–196.
Powder form
Solution form
2.010
2.010
2.038
2.039
2.182
2.183
2.076
2.077
11
11
18
16
15
15
The average g-factor is calculated from expression, gave = (gx + gy + gz)/3.
[17] S. Pathak, A. Kumar, P. Tandon, J. Mol. Struct. 981 (2010) 1–9.
[18] Y. Li, H. Zhang, Y. Liu, F. Li, X. Liu, J. Mol. Struct. 997 (2011) 110–116.
[19] G.O. Ildiz, S. Akyuz, Vib. Spectrosc. 58 (2012) 12–18.
[20] 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, V. Bakken, 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 Inc., Wallingford CT, 2004.
[21] Todd Keith, John Millam, GaussView, Version 4.1, Roy Dennington II,
Semichem Inc., Shawnee Mission, KS, 2007.
To simulate the experimental spectra, we wrote a software in
Matlab scientific language. All line width and EPR fit parameters
are given in the Table 5. We obtained the best fit by using the
Lorentzian line shape function for intrinsic line property of exper-
imental signals. As seen in the Fig. 7 the simulated spectra exhibit
all features of the experimental ones. The spectrum recorded from
solution form has almost same EPR and line width fit parameters
with powder one. However, it is quite resonable to expect remark-
able changes at the EPR characteristics of a powder sample when it
is in a solvent. Many Cu2+ coordinated complexes exhibit hyperfine
splittings or quasi-isotropic behavior according effects of solvent
[43,51]. This unexpected case might be attributed to distorted
polymeric structure of our powder complex. The polymeric struc-
ture continues in the solution form, in other words, the environ-
ment of paramagnetic ion does not change and any remarkable
changes at EPR characteristics are not observed.
[22] G. Keresztury, Raman spectroscopy: theory, in: J.M. Chalmers, P.R. Griffiths
(Eds.), Handbook of Vibrational Spectroscopy, vol. 1, John Wiley & Sons Ltd.,
New York, 2002.
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Acta A 49 (1993) 2007–2026.
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Wiley, New York, 1974.
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Compound, Wiley, New York, 1981.
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second ed., New Age International, New Delhi, 2004.
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[34] G. Keresztury, Raman spectroscopy: theory, in: J.M. Chalmers, P.R. Griffiths
(Eds.), Handbook of Vibrational Spectroscopy, vol. 1, John Wiley & Sons,
2002.
[35] V. Küçük, A. Altun, M. Kumru, Spectrochim. Acta Part A 85 (2012) 92–98.
[36] M. Kumru, V. Küçük, T. Bardakçı, Spectrochim. Acta Part A 90 (2012) 28–34.
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251.
Conclusion
Cu(3A1MB)2Cl2 was synthesized and characterized by elemen-
tal analysis, FT-IR, FT-FIR, dispersive Raman and EPR spectra. The
molecular geometry, vibrational frequencies, infrared intensities
and Raman scattering activities of the title molecules calculated
with DFT/B3LYP method using 6–311G+(d,p) basis set. By compar-
ing relative energy values one can observe that conformed 1 is
more stable than conformer 2. So, the complex has a shape as con-
former 1 and must have one unpaired electron. Additionally, a
bond formation between Cu(II) atom and 3A1MB was observed,
that is N atom of the free ligand coordinates to the metal atom.
Although vibrational studies do not reveal sufficient unambiguous
information on stereochemistry of Cu(3A1MB)2Cl2, EPR studies
mention distorted polymeric structure of our powder complex.
Appendix A. Supplementary material
[38] M. Kumru, V. Küçük, P. Akyürek, Spectrochim. Acta Part A 113 (2013) 72–79.
[39] L.F. Yang, Z. Peng, X. Ren, G. Cheng, P. Cai, Spectrochim. Acta Part A 57 (2001)
2745–2764.
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[42] M. Labanowska, E. Bidzinska, A. Parab, M. Kurdziela, Carbohyd. Polym. 87
(2012) 2605.
Supplementary data associated with the Raman intensities of
the title molecules using the laser wavelength of 532 nm can be
found, in the online version, at http://dx.doi.org/10.1016/
j.saa.2013.12.068.
[43] S. Güner, M.K. Sener, H. Dinçer, Y. Köseog˘lu, S. Kazan, M.B. Koçak, J. Magn.
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