A new copper(II) Schiff base complex containing asymmetrical tetradentate N2O2 Schiff base ligand: Synthesis, characterization, crystal structure and DFT study

Article abstract of DOI:10.1016/j.molstruc.2014.10.058

(Graph Presented) A new copper (II) Schiff base complex, CuL¹, was prepared from the reaction of asymmetrical Schiff base ligand of L¹ and Cu(OAC)₂ (L¹ = salicylidene imino-ethylimino-pentan-2-one). The Schiff b

Full text of DOI:10.1016/j.molstruc.2014.10.058

Accepted Manuscript
A new Cu(II) Schiff base complex containing asymmetrical tetradentate N2O2
Schiff base ligand: synthesis, characterization, crystal structure and DFT study
Gholamhossein Grivani, Sara Husseinzadeh Baghan, Mohammad Vakili,
Aliakbar Dehno Khalaji, Vida Tahmasebi, Václav Eigner, Michal Dušek
PII:
S0022-2860(14)01071-0
DOI:
http://dx.doi.org/10.1016/j.molstruc.2014.10.058
MOLSTR 21054
Reference:
Journal of Molecular Structure
To appear in:
Received Date:
Revised Date:
Accepted Date:
3 August 2014
26 September 2014
16 October 2014
Please cite this article as: G. Grivani, S.H. Baghan, M. Vakili, A.D. Khalaji, V. Tahmasebi, V. Eigner, M. Dušek,
A new Cu(II) Schiff base complex containing asymmetrical tetradentate N2O2 Schiff base ligand: synthesis,
characterization, crystal structure and DFT study, Journal of Molecular Structure (2014), doi: http://dx.doi.org/
10.1016/j.molstruc.2014.10.058
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A new Cu(II) Schiff base complex containing asymmetrical tetradentate N2O2
Schiff base ligand: synthesis, characterization, crystal structure and DFT
study
Gholamhossein Grivania,*, Sara Husseinzadeh Baghana, Mohammad Vakilib, Aliakbar Dehno
Khalajic, Vida Tahmasebia, Václav Eignerd, e, Michal Dušeke
aSchool of Chemistry, Damghan University, Damghan, P. O. Box 36715-364, Iran
bDepartment of Chemistry,Ferdowsi University of Mashhad, Mashhad 91775-1436, Iran
cDepartment of Chemistry, Faculty of Science, Golestan University, Gorgan, Iran
dDepartment of Solid State Chemistry, Institute of Chemical Technology, Technická 5, 166 28
Prague, Czech Republic
eInstitute of Physics AS CR, v.v.i., Na Slovance 2, 182 21 Prague 8, Czech Republic
Abstract
A new copper (II) Schiff base complex, CuL1, was prepared from the reaction of asymmetrical
Schiff base ligand of L1 and Cu(OAC)2 (L1 = salicylidene imino-ethylimino-pentan-2-one). The
Schiff base ligand, L1, and its copper (II) complex, CuL1, have been characterized by elemental
1
analysis (CHN) and FT-IR and UV-vis spectroscopy. In addition, H NMR was employed for
characterization of the ligand. Thermogrametric analysis of the CuL1 reveals its thermal stability
and its decomposition pattern shows that it is finally decomposed to the copper oxide (CuO). The
crystal structure of CuL1 was determined by the single crystal X-ray analysis. The CuL1 complex
crystallizes in the monoclinic system, with space group P21/n and distorted square planar
coordination around the metal ion. The Schiff base ligand of L1 acts as a chelating ligand and
1

coordinates via two nitrogen and two oxygen atoms to the copper (II) ion with C1 symmetry. The
structure of the CuL1 complex was also studied theoretically at different levels of DFT and basis
sets. According to calculated results the C-O bond length of the salicylate fragment is slightly
higher than that in the acetylacetonate fragment of ligand, which could be interpreted by
resonance increasing between phenyl and chelated rings in ligand in relative to the
acetylacetonate fragment.
Keywords: Schiff-base · Copper(II) · Complex · Single-crystal · Thermal decomposition . DFT.
1. Introduction
Schiff base ligands have been focused as attractive topic in inorganic chemistry due to their
simple synthesis; versatility and chelating with main group and transition metals [1-3]. The metal
ion in such complexes can be coordinated by the iminic nitrogen atom and other donor atoms in
the Schiff base molecules which leading to many interesting properties such as ability to
reversibly bind oxygen in epoxidation reactions, catalytic role in hydrogenation of olefins [4],
photochromic compounds [5], materials for non-linear optics [6], magnetic compounds [7], and
biological application [8-13]. while synthesis of transition metal complexes with symmetrical
tetradentate Schiff base ligands have been thoroughly studied [14-17], only a few asymmetrical
complexes are available [18,19]. Asymmetrical Schiff base ligands are one of the most important
compounds and received much attention due to the bounding of central metal ions with
asymmetrical ligands in natural systems [20-22] and also optoelectronic, electrochemical and
magnetic properties [23-25]. This class of compounds has been recommended useful probes for
the study of low symmetry complexes related to the low symmetry sites found in metalloproteins
2

[26]. Herein, we describe the synthesis, characterization and crystal structure determination of a
new CuL1 complex (Scheme 1), of asymmetric tetradentate N2O2 Schiff base ligand of L1. The
experimental structure was compared with the theoretical calculation results at different levels of
DFT and basis sets.
<Scheme 1>
2. Experimental
2.1. Physical Techniques and Materials
All reagents and solvents for synthesis and analysis were commercially available and
purchased from Merck and used as received without further purifications. Infrared spectra were
recorded using KBr disks on a FT-IR Perkin Elmer spectrophotometer. Elemental analyses were
carried out using a Heraeus CHN–O–Rapid analyzer and results agreed with calculated
values.1HNMR spectrum of ligand was measured on a BRUKER DRX-400 AVANCE
spectrometer at 500 MHz for the Schiff-base ligand. The TG analysis was performed on a Perkin
Elmer TG/DTA lab system in air atmosphere with a heating rate of 20 ◦C/min in the temperature
range 30–660 ◦C.
2.2. Method of analysis
In this study, the molecular structure of CuL1 complex was computed with the Gaussian 09W
software system by using a selection of unrestricted modern density functional [27]. The B, B3,
G96 and X3 exchange functional were combined with the LYP [28-32] correlation functional,
resulting in the four different functional B3LYP (with the 6-311G* and 6-31G* basis sets),
BLYP(with the 6-311G* and 6-31G* basis sets), G96LYP(with the 6-311G* basis set), and
3

X3lyp(with the 6-311G* basis set). Some calculated bond distances, and angles of CuL1 are listed
in Table 2.
2.3. Synthesis of the L1
The L1 ligand prepared in two steps: At first, the acacen compound was prepared as
described in refs [33-36]. A solution of 10 mmol( 1 g ) of acetylactone in 50 ml chloroform was
added drop wise to a solution of 10 mmol( 0.60 g ) ethylenediamine in 50 ml of chloroform in a
250 ml round bottom flask at 30 min with stirring at room temperature. After stirring for 3 h, the
solvent was evaporated and the resulting content was reacted with a solution of 10 mmol of 2-
hydroxy-benzaldehyde( 1.22 g ) in 50 ml of methanol and refluxed for 2 h. After evaporation of
the solvent, the yellow precipitates were dried in air( Yield: 2.23 g .91%). M.p.: 55°C. Anal.Calc.
for C14H18N2O2: C, 68.08; H, 7.23; N, 11.31%. Found: C, 68.29; H, 7.31; N, 11.38%. IR (KBr
pellet, cm-1): 2800-3053 (w, C-Haliphatic and aromatic), 1630 (s, C=N), 1605 (s, C=N), 1425,
1456, 1500, 1571 (m, C=C), 1283 (m, C-O).1H NMR (CDCl3, δ (ppm)): 13.02-13.23 (1Hl,-O-H),
10.91 (1Ha,-O-H),8.36 (1Hg, H-C=N-), 6.84-7.34 (4Hh,i,j,K,Ar-H), 4.95-5 (1Hc, C-H), 3.42-3.94
(2He,-CH2) (2Hf, -CH2), and 1.91-2 (3Hb, -CH3) (3Hd, -CH3). UV-Vis (CH3CN, λmax/nm): 224,
264, 320.
2.4. Synthesis of (salicylidene imino-ethylimino-pentan-2-one) Cu(II)، CuL1
In a 100 ml round bottom flask, 1mmol ( 0.24 g ) of L1 was dissolved in 50 ml of MeOH
and to this solution was added 1 mmol( 0.19 g ) of copper (II) acetate dissolved in 15 ml of
MeOH. The content was refluxed with stirring for 2 h. After evaporating the solvent, the Violet
crystals were prepared (Yield: 0.25 g. 82%). M.p.: 185°C. Anal.Calc. for Cu(C14H16N2O2): C,
55.77; H, 5.13; N, 9.05%. Found: C, 54.58; H, 5.19; N, 9.09%. IR (KBr pellet, cm-1 ): 1596 (s,
4

C=N), 1630 (s, C=N), 1445, 1511 (m, C=C), 1360 (m, C-O). UV-Vis (CH3CN, λmax/nm): 228,
270, 320, 362. The suitable single crystals for X-ray crystallography were obtained by slow
evaporation from a solution of the CuL2 complex in chloroform.
2.5. X-ray structure determination of CuL1
A single crystal of CuL1 with approximate dimensions of 0.53 mm × 0.08 mm × 0.04 mm
was used in the X-ray diffraction experiment. Diffraction data were measured on a Bruker–
Nonius X8 ApexII diffractometer equipped with a CCD area detector by using graphite-
monochromated Mo Ka radiation (k = 0.71073 Å) generated from a sealed tube source. Data
were collected and reduced by smart and saint software [37] in the Bruker package. The structure
was solved by direct methods [38] and then developed by least squares refinement on F2 [39, 40].
Crystallographic data and details of the data collection, structure solution and refinements are
listed in Table 1. Selected bond distances, and angles of CuL1 are listed in Table 2.
<Table 1>
<Table 2>
3. Results and discussion
3.1. Synthesis and characterization
The Schiff base ligand, salicylideneimino-ethylimino-pentan-2-one (L1), was prepared in
two steps. The acacen compound was synthesized by reaction of equimolar of etylendiamine and
acetylacetone in chloroform. Subsequently the ligand L1 was synthesized in a simple preparation
procedure by the reaction of acacen and 2-hydroxy-benzaldehyde in methanol as a solvent in the
reflux conditions. Then by reaction of this prepared Schiff base ligand with Cu(OAc)2 in MeOH
5

as a solvent in the reflux conditions the violet (salicylideneimino-ethylimino-pentan-2-one)
Cu(II) Schiff base complex was prepared (Scheme1). The asymmetrical tetradentate Schiff base
ligand (L1) and its copper (II) complex (CuL1) were characterized by FT-IR and UV-vis
1
spectroscopy and elemental analysis (CHN). In addition H NMR spectroscopy was also used to
1
further characterization of L1. The H NMR spectrum of L1 and its assignment were showed in
Fig. 1, which finely confirmed the functional groups of the ligand. Two signals at 1.91 and 2 ppm
were corresponded to the protons of b and d of the two methyl groups. The signals at 3.42-3.94
ppm were also assigned to aliphatic methylene protons of f, f′ and e, e′. These four methylene
protons show different behavior and show four resonances and can be assigned as: one doublet at
3.424 ppm(3J= 2.8 Hz) for e, one multiplex at 3.519 ppm for e′, one triplet at 3.787(3J= 6 Hz )
for f and one doublet at 3.868 ppm(3J= 20.8 Hz) for f′ with the integration retia of 1: 1: 1: 1. This
behavior can be related to asymmetric structure of the L1. At the region of 4.95-5.01 ppm they
are seen two separated singlet resonances in 4.957 and 5.009 ppm because of enol-ketone forms
of L1 in the acetylate moiety. The only iminic proton (g) shows a singlet resonance at 8.36 ppm,
and the signals of aromatic H atoms (h, k, i, j) appear as multiplex resonances at 6.84-7.34 ppm.
3
The resonance of k is seen as triplet with J= 6.4 Hz. In the down field region of spectrum that
appeared at 10.91 ppm related to the phenolic proton whereas the two peaks at 13.02-13.21 ppm
attributed to the enole imine and keto amine form of Schiff base ligand in the phenolate moiety
(Fig. 1).
Fig. 2 shows the FT-IR spectrum of L1 and CuL1. The FT-IR spectrum of the Schiff base ligand,
L1, shows two strong band at 1630 and 1605 cm-1, attributed to the two different -C=N- stretching
vibration frequencies. According to experimental and theoretical bond lengths, we assign the first
IR band to the acetylacetonate -C=N- stretching mode of ligand and the latter band to the
6

salicylate -C=N- stretching mode of ligand, respectively. The FT-IR spectrum also shows several
weak bands for the aromatic and aliphatic C-H stretching vibration frequencies at the region of
2800-3053 cm-1, and strong bands for the aromatic C=C stretching vibration frequencies at the
region of 1425-1571 cm-1.Two sharp peaks at 1630 and 1596 related to different -C=N- groups in
CuL1 complex. The vibrational frequency of salicylate -C=N- group was shifted to the lower
frequencies due to anionic character of phenolate and long resonance with aromatic ring. The two
strong bands at 1445 and 1511 cm-1 attributed to the aromatic C=C stretching vibrations (Fig. 2).
The electronic absorption spectrum of CuL1 and L1 in acetonitrile was recorded in the range
of 210-780 nm (Fig. 3).The complex exhibits four intense absorption bands at 228, 270, 320 and
362 nm, in the UV regin. Comparison with the absorption spectrum of free L1 (Fig. 3) confirm
that these sharp bands are ligand-centered (LC) due to π→π* and n→π* transitions of the metal-
bound L1chromophores, which are only somewhat perturbed by complexation. Furthermore, the
complex shows a broad band with very low energy absorption at 570 nm, which attributed to the
d–d transitions of the copper(II) center.
<Fig. 1>
<Fig. 2>
<Fig. 3>
3.2. Description of the crystal and molecular structure
In order to confirm the chemical structure of the complex, single crystal X-ray analysis was
used to determine of the structure of the CuL1 complex. An ORTEP view of the CuL1 Schiff base
complex with the atoms numbering scheme is given in Fig. 4. For comparison, the geometrical
parameters of this compound were investigated by means of density functional theory (DFT)
7

calculations at the B3LYP, BLYP, G96LYP, and X3LYP levels using 6-31G* and 6-311G* basis
sets, and the results were compared with the experimental data (see Table2). Table 2 lists selected
experimental and theoretical bond lengths and angles. According to this Table, the agreement
between the most geometrical parameters calculated at the different DFT levels and the
experimental data is satisfactory except for Cu1-N9, Cu1-N12, N9-C8, O1-C2, O16-C15, C14-
C15, and C7-C8 bond lengths, which are significantly different. These discrepancies could be
attributed to the fact that X-ray measurement has been done in the solid state, whereas the
computed refers to the isolated complex in the gas phase. The best agreement between theoretical
and experimental data were obtained by using uB3LYP, uBLYP, and uX3LYP levels with 6-
311G* basis set.
It is worthy to note that the calculated Cu1-N12 and Cu1-O16 bond lengths of CuL1 are
different from those in bis(4-aminopent-3-en-2-onato)copper(II), Cu(APO)2, reported by M.
Jamialahmadi et al. The corresponding bond lengths in Cu(APO)2 are 1.920 and 1.955Å,
respectively, calculated at B3lyp/6-311G*[41], while the other bond lengths (C13-C14, C14-C15,
and C13-C17/C14-C15) of Cu(APO)2 are almost the same as those in CuL1. The calculated C13-
C14, C14-C15, and C13-C17/C14-C15 bond lengths in Cu(APO)2 are 1.418, 1.392, and 1.514Å,
respectively [42].
In this complex, the Schiff base ligand is N2O2 tetradentate. The square planar geometry
around the copper (II) ion in this complex is distorted because of the different bond distances and
angles. All bond distances and angles are normal and are in good agreement with those reported
in similar Schiff-base compounds. The experimental C(8)-N(9) bond length of 1.284(3) Å is
close to the value for a double bond, while the C(10)- N(9) bond length of 1.466(3) Å is close to
the value for a single bond, like in similar Schiff bases [43, 44]. The bond angles for atoms C(7)-
C(8)-N(9) and C(14)-C(13)-C(17) are 125.50(2)° and 116.90(2)°, respectively, which is
8

consistent with the sp2 hybrid character of C(8) and C(13) atoms. According to calculated results,
the dihedral angle between the phenyl and the chelated rings (C2-C7-C8-N9) is about 3.0-4º (see
Table 2) which indicates the resonance between phenyl group with the π-electron system of the
chelated ring. This resonance causes the sp2 hybrid character of C(8) and explains the C(8)-N(9)
bond length. Table 2 shows that the calculated bond lengths of C2-C7 is longer than that in the
residual C-C bond lengths in phenyl ring. This difference also suggests significant resonance
between phenyl group with the N9-C8-ph fragment in complex. This complex shows non-
classical C-H...O intermolecular hydrogen bonds linking the monomeric units to each other (Fig.
5, Table 3).
<Fig. 4>
<Fig. 5>
<Fig. 6>
<Table. 3>
3.3. Thermal studies
The TGA/DTG/DTA profile of the CuL1 complex is shown in Fig. 6. It is decomposed in
o
two stages occurring at the temperature range of 210-559 C. After thermal decomposition of
CuL1, 26.23% (calc. 25.86%) of its initial weight will be remained. Thus by regarding to the total
weight loss of the CuL1, after wasting all of the organic components, the complex is converted to
the copper oxide(CuO).
<Fig. 7>
9

4. Conclusion
In conclusion the asymmetric Schiff base ligand of L1 was prepared in two simple preparation
step and it was characterized by elemental analysis, FT-IR and 1HNMR spectra. After synthesis
and characterization of the CuL2 complex, the molecular and crystal structures were determined
by single crystal X-ray diffraction and calculated at the DFT levels. The best agreement between
theoretical and experimental were obtained by using uB3LYP, uBLYP, and uX3LYP levels with
6-311G* basis set. However, because of the special structure of the single crystal of CuL1, the
observed metal-ligand bond lengths were somewhat deviated from the theoretical results.
5. Acknowledgements
We acknowledge the Damghan University (DU) for partial support of this work. Structure
analysis was supported by the project 14-03276S of the Grant Agency of the Czech Republic.
6. Appendix A. Supplementary data
Crystallographic data (excluding structure factors) for the structure reported in this paper has
been deposited with the Cambridge Crystallographic Center, CCDC No 1013907. (Copies of the
data can be obtained free of charge on application to The Director, CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK, fax: +44 1223 336 033, e-mail: deposit@ccdc.cam.ac.uk or
http:www.ccdc.cam.ac.uk).
10

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14

O
H
NH2
N
N
C
O
O
N
HO
CHCl 3
r.t/3h
OH
CH3OH
Ref/4h
HO
NH2
NH2
OH
L1
N
O
N
O
C
Cu(CH3COO)2.H2O
Cu
CH3OH
Ref/2h
CuL1
Scheme 1. Preparation procedures of (L1) and its copper(II) complex (CuL1).
15

Fig. 1.1H NMR spectrum of L1.
16

Fig. 2. FT-IR spectrum of L1 (a) and CuL1 (b).
17

Fig. 3. Electronic spectra of CuL1 and free ligand in acetonitrile (10-4 M).
18

Fig. 4. An ORTEP view of CuL1, with the atom numbering scheme.
19

Fig.5. Crystal packing of CuL1. Dashed lines represent the hydrogen bonds.
20

Fig. 6. The TGA/DTG/DTA profiles of the CuL1.
21

Table 1
Crystallographic data and experimental details for CuL1
CuL1
Chemical formula
Formula weight
Crystal system
Space group
T, K
C14H16Cu1N2O2
307.8
Monoclinic
P21/n
120.0 (1) K
7.6096 (2)
10.0446 (4)
17.2598 (7)
102.090 (3)°
1290.00 (8)
4
a, Å
b, Å
c, Å
β, deg
V, Å3
Z
µ, mm-1
2.39
Measured reflections
Independent reflections
reflections with I > 3σ(I)
Rint, S
8372
2251
1971
0.023, 1.74
172
Number of parameters
R[F2 > 2σ(F2)]
wR(F2)
0.035
0.102
∆ρmax, ∆ρmin (e.A-3)
0.74, -0.64
22

Table 2
Selected experimental (X-ray) and calculated geometrical parameters for CuL1
uG96LY
P
uX3LY
P
uB3LYP
uBLYP
Experimenta
l
6-
311G*
6-31G*
6-311G*
6-31g*
6-311g*
6-311g*
Bond lengths (Å)
Cu1-O1
1.910
1.917
1.939
1.935
1.284
1.466
1.462
1.316
1.299
1.299
1.419
1.505
1.377
1.508
1.443
1.919
1.923
1.952
1.959
1.294
1.457
1.462
1.319
1.288
1.274
1.413
1.516
1.399
1.513
1.427
1.901
1.894
1.938
1.933
1.297
1.458
1.462
1.322
1.297
1.282
1.414
1.518
1.400
1.514
1.428
1.946
1.944
1.954
1.969
1.308
1.471
1.474
1.331
1.302
1.289
1.423
1.528
1.408
1.525
1.434
1.911
1.915
1.924
1.936
1.313
1.472
1.475
1.335
1.312
1.298
1.424
1.529
1.408
1.526
1.435
1.942
1.940
1.948
1.962
1.307
1.469
1.473
1.330
1.299
1.287
1.421
1.526
1.407
1.524
1.432
1.916
1.920
1.951
1.957
1.293
1.456
1.460
1.318
1.287
1.272
1.412
1.515
1.398
1.511
1.426
Cu1-O16
Cu1-N9
Cu1-N12
N9-C8
N9-C10
N12-C11
N12-C13
O1-C2
O16-C15
C13-C14
C13-C17
C14-C15
C15-C18
C7-C8
Bond angles (º)
O1-Cu1-N9
O1-Cu1-N12
O1-Cu1-O16
93.31
174.28
87.92
91.61
173.82
90.20
93.06
161.51
92.48
91.93
175.18
88.86
93.82
159.27
91.74
91.75
175.01
88.95
91.62
173.79
90.20
23

86.5502
4
N9-Cu1-N12
N9-Cu1-O16
N12-Cu1-O16
N12-C13-C14
N12-C13-C17
C14-C13-C17
C13-C14-C15
C14-C15-O16
O16-C15-C18
C10-C11-N12
Cu1-N12-C11
Cu1-N12-C13
Cu1-O16-C15
Cu1-O1-C2
O1-C2-C3
84.99
170.35
94.67
122.40
120.70
116.90
126.60
125.60
114.70
109.50
113.40
125.70
124.80
127.60
118.70
125.50
-
85.22
175.39
93.36
85.63
163.02
94.06
85.77
176.63
93.68
85.93
176.22
93.66
85.19
175.37
93.37
160.42
94.78
122.70
120.30
117.00
125.55
126.00
114.66
108.25
111.54
125.98
126.22
128.62
118.96
125.60
3.00
122.16
120.59
117.24
125.57
125.83
114.70
107.68
111.76
125.94
125.67
128.31
118.74
125.23
3.04
122.42
120.42
117.15
125.92
126.18
114.36
108.26
111.07
126.10
125.46
127.69
118.62
125.53
3.12
121.75
120.75
117.50
125.95
125.86
114.48
107.50
111.33
126.13
124.84
127.32
118.43
125.02
4.26
122.37
120.50
117.13
125.86
126.09
114.44
108.19
111.04
111.04
125.59
127.88
118.75
125.50
3.09
122.72
120.27
117.01
125.50
126.00
114.67
108.23
111.58
125.97
126.26
128.67
118.98
125.58
3.00
C7-C8-N9
C2-C7-C8-N9a
R2 b
-
0.99966
0.16
0.99836
1.00
0.99961
0.22
0.99774
-0.62
0.99795
0.30
0.99966
0.16
a c
-
bd
-
1.00
1.00
1.00
1.02
1.00
1.00
SDe
-
0.30
0.66
0.32
0.77
0.73
0.30
a Dihedral angle
b R2; regression coefficient
c a; slope
d b; intercept
e SD; standard deviation
24

Table 3
Intermolecular hydrogen bonds geometries (Å, °) in the crystal packing of CuL1
D-H···A
D-H
H···A
D···A
D-H···A
C10-H1c10···O1i
C10-H1c10···O16i
C10i-H1c10i···O1
C10i-H1c10i···O16
0.960
0.960
0.960
0.960
2.365
2.930
2.365
2.930
3.232
3.562
3.232
3.562
150.04
124.53
150.04
124.53
25

A new Cu(II) Schiff base complex containing unsymmetrical tetradentate N2O2 Schiff
base ligand: synthesis, characterization, crystal structure and DFT study
Gholamhossein Grivania,*, Sara Hosseinzadea, Mohammad Vakilib, Aliakbar Dehno Khalajic, Vida Tahmasebia,
Václav Eignerd, e, Michal Dušeke
aSchool of Chemistry, Damghan University, Damghan, P. O. Box 36715-364, Iran
bDepartment of Chemistry,Ferdowsi University of Mashhad, Mashhad 91775-1436, Iran
cDepartment of Chemistry, Faculty of Science, Golestan University, Gorgan, Iran
dDepartment of Solid State Chemistry, Institute of Chemical Technology, Technická 5, 166 28 Prague, Czech
Republic
eInstitute of Physics AS CR, v.v.i., Na Slovance 2, 182 21 Prague 8, Czech Republic
26

27

Highlights
• A new asymmetrical CuL1 Schiff base complex was prepared
• It characterized by elemental analysis, FT-IR and UV-vis spectroscopy
• TGA/DTG/DTA of the CuL1 reveals its thermal stability and decomposition to CuO
• Its crystal structure was studied by X-ray diffraction and DFT calculation
• The most geometrical parameters at DFT levels agree with the X-ray data
.
28