Preparation, spectral, X-ray powder diffraction and computational studies and genotoxic properties of new azo-azomethine metal chelates

Article abstract of DOI:10.1016/j.molstruc.2014.07.005

A new tridentate azo-azomethine ligand, N′-[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}methylidene]benzohydrazidemonohydrate, (sbH·H₂O) (1), is prepared by condensation of benzohydrazide and 2-hydroxy-5-[(4-nitrophenyl)diazenyl]benzaldehyde (a) with treatment of a solution of diazonium salt of p-nitroaniline and 2-hydroxybenzaldehyde in EtOH. The five coordination compounds, [Co(sb)₂]·4H₂O (2), [Ni(sb)₂]·H₂O (3), [Cu(sb)₂]·4H₂O (4), [Zn(sb)₂]·H₂O (5) and [Cd(sb)₂]·H₂O (6) are prepared by reacting the Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with the ligand. The structures of the compounds are elucidated from the elemental analyses data and spectroscopic studies. It is found the ligand acts as a tridentate bending through phenolic and carbonyl oxygens and nitrogen atom of the CN group similar to the most of salicylaldimines. Comparison of the infrared spectra of the ligand and its metal complexes confirm that azo-Schiff base behaves as a monobasic tridentate ligand towards the central metal ion with an ONO donor sequence. Upon complexation with the ligand, the Cd(II), and Zn(II) ions form monoclinic structures, while Co(II), Cu(II) and Ni(II) ions form orthorhombic structures. Quantum chemical calculations are performed on tautomers and its metal chelates by using DFT/B3LYP method. Most stable tautomer is determined as tautomer (1a). The geometrical parameters of its metal chelates are obtained as theoretically. The NLO properties of tautomer (1a) and its metal complexes are investigated. Finally, the ligand and its metal complexes are assessed for their genotoxicity.

Full text of DOI:10.1016/j.molstruc.2014.07.005

Journal of Molecular Structure 1076 (2014) 213–226
Contents lists available at ScienceDirect
Journal of Molecular Structure
journal homepage: www.elsevier.com/locate/molstruc
Preparation, spectral, X-ray powder diffraction and computational
studies and genotoxic properties of new azo–azomethine metal chelates
a
b
c
a
d
a,
⇑
Sß irin Bitmez , Koray Sayin , Bari ßs Avar , Muhammet Köse , Ahmet Kayraldız , Mükerrem Kurto g˘ lu
a
Department of Chemistry, Kahramanmaras Sutcu Imam University, 46100 Kahramanmaras, Turkey
Department of Chemistry, Cumhuriyet University, 58140 Sivas, Turkey
Department of Metallurgy and Materials Engineering, Bulent Ecevit University, 67100 Zonguldak, Turkey
Department of Biology, Kahramanmaras Sutcu Imam University, 46100 Kahramanmaras, Turkey
b
c
d
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
ꢀ
A novel azo–azomethine ligand and
its transition metal complexes were
synthesized and characterized.
The crystallinity of the azo–
azomethine dye and its metal
complexes were studied by X-ray
powder diffraction.
ꢀ
ꢀ
ꢀ
The geometrical parameters of the
compounds are obtained as
theoretically. The NLO properties of
compounds are investigated.
Finally, the ligand and its metal
complexes are assessed for their
genotoxicity.
a r t i c l e i n f o
a b s t r a c t
0
Article history:
Received 8 May 2014
Received in revised form 3 July 2014
Accepted 3 July 2014
Available online 22 July 2014
A
new tridentate azo–azomethine ligand, N -[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}methyli-
dene]benzohydrazidemonohydrate, (sbHꢁH O) (1), is prepared by condensation of benzohydrazide and
-hydroxy-5-[(4-nitrophenyl)diazenyl]benzaldehyde (a) with treatment of a solution of diazonium salt of
p-nitroaniline and 2-hydroxybenzaldehyde in EtOH. The five coordination compounds, [Co(sb)
]ꢁ4H
2), [Ni(sb) O (3), [Cu(sb) ]ꢁ4H O (4), [Zn(sb) ]ꢁH O (5) and [Cd(sb) ]ꢁH O (6) are prepared by reacting
]ꢁH
2
2
2
2
O
(
2
2
2
2
2
2
2
2
the Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) ions with the ligand. The structures of the compounds are eluci-
dated from the elemental analyses data and spectroscopic studies. It is found the ligand acts as a triden-
tate bending through phenolic and carbonyl oxygens and nitrogen atom of the C@NA group similar to the
most of salicylaldimines. Comparison of the infrared spectra of the ligand and its metal complexes con-
firm that azo-Schiff base behaves as a monobasic tridentate ligand towards the central metal ion with an
ONO donor sequence. Upon complexation with the ligand, the Cd(II), and Zn(II) ions form monoclinic
structures, while Co(II), Cu(II) and Ni(II) ions form orthorhombic structures. Quantum chemical calcula-
tions are performed on tautomers and its metal chelates by using DFT/B3LYP method. Most stable tauto-
mer is determined as tautomer (1a). The geometrical parameters of its metal chelates are obtained as
theoretically. The NLO properties of tautomer (1a) and its metal complexes are investigated. Finally,
the ligand and its metal complexes are assessed for their genotoxicity.
Keywords:
Azo–azomethine
Spectroscopy
DFT studies
X-ray powder diffraction
Genotoxicity
Ames test
Ó 2014 Elsevier B.V. All rights reserved.
⇑
Corresponding author. Tel.: +90 344 280 1450; fax: +90 344 280 1352.
E-mail addresses: mkurtoglu@ksu.edu.tr, kurtoglu01@gmail.com (M. Kurto g˘ lu).
http://dx.doi.org/10.1016/j.molstruc.2014.07.005
022-2860/Ó 2014 Elsevier B.V. All rights reserved.
0

2
14
Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
Introduction
ligand sbH and its Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) metal com-
plexes were tested for their genotoxic properties.
Azo-Schiff bases play an important role in inorganic chemistry
as they easily form stable complexes with most transition metal
ions such as cobalt(II), nickel(II) and copper(II). The development
of the field of bioinorganic chemistry has increased the interest
in Schiff base complexes, since it has been recognized that many
of these complexes may serve as models for biologically important
species [1–3]. Schiff base ligands are well known for their wide
range of applications in pharmaceutical and industrial fields
Experimental
Reagents
All reagents and solvents used were supplied by Merck chemi-
cal company and were used without further purification.
[
4–6]. Transition metal complexes of polydentate Schiff base ligand
Physical measurements
have great applicabilities in catalysis and material chemistry [7].
Moreover, the hydrazone group plays an important role for the
antimicrobial activity and possesses interesting antibacterial, anti-
fungal [8,9], anti-tuberculosis activities [10,11]. These groups of
compounds are important class of ligands which present in numer-
ous physiological and biological applications as antitumour agents,
insecticides, anticoagulants, anticonvulsant, anti-inflammatory,
analgesic, antioxidants, antiplatelet and plant growth regulators
1H NMR spectrum of the ligand was obtained in deuterated
DMSO as solvent on a Bruker FT-NMR AC-400 (300 MHz) spec-
trometer. All chemical shifts are reported in d (ppm) relative to
the tetramethylsilane as internal standard. Carbon, hydrogen and
nitrogen elemental analyses were performed with a model LECO
CHNS 932 elemental analyzer. IR spectra were obtained using
ꢂ1
KBr discs (4000–400 cm ) on a Perkin Elmer FT-IR spectropho-
[
12–16]. These properties of the hydrazones are attributed to the
tometer. The UV–Vis spectra of DMSO solutions in the
200–800 nm range were measured on a T80+ UV–Vis. Spectrome-
ter PG Instruments LTD spectrometer. X-ray powder diffraction
analysis was performed by PANanalytical X’Pert PRO instrument
formation of stable metal complexes with some metals which cat-
alyze physiological processes. Their metal complexes, have also
found applications in various chemical processes like nonlinear
optics, sensors, medicine [17].
with Cu K
a radiation (wavelength 0.154 nm) operating at 40 kV
Recently, azo-Schiff bases and their metal complexes were
reported by our group [18–20]. In view of the versatile importance
of azo–azomethines, hydrazones and their metal complexes, we
herein describe the preparation and identification of Co(II), Ni(II),
Cu(II), Zn(II) and Cd(II) metal complexes of N’-[{2-hydroxy-5-
and 30 mA. Measurements were scanned for diffraction angles
(2h) ranging from 5° to 50° with a step size of 0.02° and a time
per step of 1 s. Melting points were obtained with a Electrothermal
LDT 9200 Apparatus in open capillaries.
[(4-nitrophenyl)diazenyl]phenyl}methylidene]benzohydrazidemonohy-
Synthesis of 2-hydroxy-5-[(4-nitrophenyl)diazenyl]benzaldehyde, (a)
drate, sbH. The chemical equations concerning the formation of the
sbH ligand represented as Scheme 1. The newly synthesized
azo–azomethine ligand and its metal chelates were characterized
by their IR, electronic, and elemental analyses data. Finally, the
The azo-coupled salicylaldehyde was synthesized using the
known coupling methods [18]. A 1.22 g (10 mmol) of salicylalde-
hyde was dissolved in distilled water (30 mL) containing 0.7 g
O
O
+
-
N
O
OH
NH2
+
N
NaNO2
N
N
-
O
HCl
-
+
N
O
N
+
N
O
O
HO
O
O
EtOH
NH2
Reflux
NH
O
-
O
+
N
NH
O
N
N
N
.
H O
2
OH
Scheme 1. The synthesis reaction of N’-[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}methylidene]benzohydrazidemonohydrate (sbHꢁH
2
O).

Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
215
0
(
8.8 mmol) of sodium hydroxide and 40 mmol of sodium carbonate
Synthesis of bis{N -[{2-hydroxo-5-[(4-nitrophenyl)diazenyl]phenyl}
during the period of 30 min at 0 °C. The resulted solution was
added slowly to the solution of diazonium chloride of 1.38 g
methylidene]benzohydrazide}copper(II)tetrahydrate, [Cu(sb)
(4)
2 2
]ꢁ4H O
(
10 mmol) p-nitroaniline in water at 0–5 °C. The reaction mixture
was stirred for 1 h at 0 °C and, then allowed to warm slowly to
the room temperature. The product was collected by filtration
and washed with a 100 mL of NaCl solution (10%) under vacuum.
A solution of CuCl2.2H
was added to the sbHꢁH
2
O (0.055 g, 0.32 mmol) in EtOH (15 mL)
O ligand solution (0.25 g, 0.64 mmol) in
EtOH (30 mL), and the mixture was refluxed with stirring for 2 h.
After stripping off the excess solvent under reduced pressure, a
brown product was obtained. Yield, 73%, decomposed at >300 °C;
2
The obtained yellowish orange solid was dried under vacuum at
1
8
0 °C overnight. Yield, 85%, m.p. 182–183 °C; orange powder.
H
NMR (d
6
-DMSO, dppm). 10.36 (s, ACHO), 8.01–7.98 (t, ArAH),
brown powder. Anal. Calcd. for C40H36CuN10O12 (840.25 g/mol):
7
.26–7.23 (d, ArAH) 7.14–7.11 (d, ArAH), 11.41 (s, ArAOH). IR(KBr,
C, 52.66; H, 3.36; N, 15.35. Found: C, 52.43; H, 3.32; N, 15.04%. IR
(KBr, cm ): 3425 (OAH), 3080 (ArACAH), 1610 (C@O), 1517
ꢂ1
ꢂ1
cm ): 3104 (OAH), 2903 (ArACAH), 1657 (C@O), 1104 (NAO).
(
C@N), 1480 (N@N), 1095 (NAO), 730 (CuAO), 518 (CuAN).
0
0
Synthesis of N -[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}
Synthesis of bis{N -[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}
methylidene]benzohydrazidemonohydrate (sbHꢁH
2
O) (1)
methylidene]benzohydrazide}zinc(II)monohydrate, [Zn(sb)
2 2
]ꢁH O (5)
A hot solution of benzohydrazide (0.865 g, 6.378 mmol) in
5 mL EtOH was mixed with hot solution (60 °C) of 2-hydroxy5-
(4-nitrophenyl)diazenyl]benzaldehyde (1.73 g, 6.378 mmol) in
the same solvent (30 mL) and the reaction mixture was stirred
magnetically under reflux for 2 h. The formed orange-yellow prod-
uct was dissolved in 25 mL EtOH and left for crystallization at room
temperature for a day. Then yellow product was collected, washed
with cold EtOH and dried in a vacuum. Yield, 60%, m.p. 291–292 °C.
This compound was prepared by the addition of Zn(CH
3
COO)
2
ꢁ
2
[
2H
2
O (0.07 g, 0.32 mmol) in EtOH (15 mL) to a refluxing mixture
O (0.25 g (0.64 mmol) in EtOH (30 mL). The
red compound was separated out on filtration, washed with cold
of the ligand sbHꢁH
2
EtOH and dried in vacuo. Yield, 85%, decomposed at >300 °C; red
powder. Anal. Calcd for C40H N10ZnO (860.14 g/mol): C, 55.85;
30 9
H, 3.52; N, 16.74. Found: C, 55.85; H, 3.335; N, 16.04%. IR (KBr):
3420 (OAH), 3085 (ArACAH), 1615 (C@O), 1522 (C@N), 1485
(N@N), 1090 (NAO), 615 (ZnAO), 523 (ZnAN).
Anal. Calcd. for C20
7.19. Found: C, 58.37; H, 4.075; N, 16.69%. IR (KBr, cm ): 3400
H
17
N
5
O
5
(407.38 g/mol): C, 58.97; H, 4.21; N,
ꢂ1
1
(
0
OAH), 3105 (ArACAH), 1650 (C@O), 1510 (C@N), 1489 (N@N),
Synthesis of bis{N -[{2-hydroxo-5-[(4-nitrophenyl)diazenyl]phenyl}
1
185 (CAO), 1070 (NAO).
methylidene]benzohydrazide}cadmium(II)monohydrate,
2 2
[Cd(sb) ]ꢁH O (6)
0
Synthesis of bis{N -[{2-hydroxo-5-[(4-nitrophenyl)diazenyl]phenyl}
To a solution of the sbHꢁH
2
O ligand (0.25 g, 0.64 mmol) in EtOH
(30 mL) was added, a solution of Cd(CH COO) O (0.086 g,
methylidene]benzohydrazide}cobalt(II)tetrahydrate, [Co(sb)
2)
2
2
]ꢁ4H O
3
2
ꢁ2H
2
(
0.32 mmol) in EtOH and the resulting solution was boiled under
reflux for 2 h. The precipitated red complex was filtered, washed
with cold EtOH and dried in vacuo. Yield, 78%, decomposed at
A solution of CoCl
2
2
ꢁ6H O (0.076 g, 0.32 mmol)) in 20 mL of EtOH
was added to a magnetically stirred 15 mL EtOH solution contain-
ing of the ligand (0.25 g, 0.64 mmol)) at 70 °C. The obtained solu-
tion was left at room temperature. The cobalt(II) complex was
obtained as dark red precipitates. The reddish brown product
was filtered, washed with EtOH, and then dried under the vacuum.
Yield, 82%, decomposed at >300 °C; reddish brown powder. Anal.
30
>300 °C; red powder. Anal. Calcd. for C40H N10CdO9. (907.14 g/
mol): C, 52.96; H, 3.33; N, 15.44. Found: C, 52.85; H, 3.16; N,
15.44%. IR (KBr): 3420 (OAH), 3100 (ArACAH), 1610 (C@O), 1533
(C@N), 1480 (N@N), 1095 (NAO), 625 (CdAO), 520 (CdAN).
Computational method
Calcd. for C40
5.43. Found: C, 53.13; H, 3.456; N, 15.48%. IR (KBr): 3420
OAH), 3100 (ArACAH), 1618 (C@O), 1518 (C@N), 1485 (N@N),
36
H N10CoO12. (837.66 g/mol): C, 52.93; H, 4.00; N,
1
(
Gaussian 09 package programs were used for all calculations
[21,22]. Density functional theory (DFT/B3LYP) method with 6-
31++G(d,p) and LANL2DZ basis sets was used for obtaining the
optimized structure of the possible tautomers and its transition
metal complexes, respectively. For organic molecules, basis sets
which contain diffuse and polar functions give the most appropri-
ate results. Therefore, 6-31++G(d,p) was selected for tautomers.
LANL2DZ basis set has been used for various complexes in many
computational studies. The calculated vibrational frequencies were
scaled by 0.95 [23] and 0.9614 [24] for B3LYP/6-31++G(d,p) and
B3LYP/LANL2DZ, respectively.
1
090 (NAO), 625 (CoAO), 515 (CoAN).
0
Synthesis of bis{N -[{2-hydroxo-5-[(4-nitrophenyl)diazenyl]phenyl}
methylidene]benzohydrazide}nickel(II)monohydrate, [Ni(sb)
3)
2 2
]ꢁH O
(
0
.25 g (0.64 mmol) of sbHꢁH
EtOH at room temperature. A solution of 0.076 g (0.32 mmol)
NiCl .6H O (10 mL) was added dropwise into 20 mL of EtOH with
2
O ligand was dissolved in 20 mL
2
2
continuous stirring. The stirred mixture was then heated to the
reflux temperature and maintained at this temperature for 2 h.
Then, the mixture was evaporated to a volume of 15 mL in vacuum
and left to cool to the room temperature. The product was filtered
in vacuum and washed with a small amount of cold ethanol. The
product was recrystallized from EtOH and dried at room tempera-
ture. Yield, 76%, decomposed at >300 °C; reddish brown powder.
Ames test
The chemicals used in the experiment
All the test substances (sbHꢁH
2
O, [Co(sb)
2
]ꢁ4H
2
O, [Ni(sb)
O) were suspended
2
]ꢁH
2
O,
[Cu(sb) O, [Zn(sb) ]ꢁH O and [Cd(sb)
2
]ꢁ4H
2
2
2
2
]ꢁH
2
in DMSO with the final concentrations of 0.80, 0.40, 0.20, 0.10
and 0.05 mg/plate, for testing mutagenicity. Mutagenicity test
tablets containing nicotinamide adenine dinucleotide phosphate
(NADP) and glucose-6-phosphate were purchased from Boehringer
Mannheim Biochemicals (Germany). DMSO (D8418), 1-histidin
(H8125), d-biotin (B4501), ampicillin (A6140), sodium azide (SA,
Anal. Calcd. for C40
N, 16.87. Found: C, 56.18; H, 3.36; N, 16.07%. IR (KBr, cm ):
H
30
N
10NiO
9
(853.42 g/mol): C, 56.29; H, 3.54;
ꢂ1
3
415 (OAH), 3115 (ArACAH), 1615 (C@O), 1520 (C@N), 1475
(
N@N), 1092 (NAO), 690 (NiAO), 515 (NiAN).

2
16
Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
S2002) and 2-aminofluorene (2-AF, A9031) were purchased from
Aldrich; agar (7178) was purchased from Aquamedia; nutrient
broth (NB, B241116) was purchased from Oxoid; 3-methylcolanth-
rene (200-276-4) was purchased from Oekanal. In this study 2-AF
environment shown in Fig. 1. Single crystals of the compounds could
not be isolated from any organic solution, thus no definite structures
can be described. However, the analytical and spectroscopic data
enables us to predict possible structures as shown in Scheme 2 and
Figs. 1 and 2.
(
dissolved in DMSO), NPD (4-nitro-o-phenylene diamine) (dis-
solved in DMSO) and SA (dissolved in bidistilled water) were used
as positive controls [25].
2
þ
reflux;EtOH
M
þ 2sbH ꢀꢀꢀꢀꢀꢀ!½MðsbÞ ꢃ:nH
2
O
2
sbHꢁH
2
O:N’-[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}meth-
Preparations of S9 mix
ylidene] benzohydrazide M = Co(II) (n = 4), Ni(II) (n = 1), Cu(II)
The albino male rats (Rattus norvegicus var. albinos) weighting
(
n = 4), Zn(II) (n = 1), Cd(II) (n = 1)
2
00 g were pre-treated with 80 mg/kg concentration of 3-meth-
ylcolanthrene (dissolved in sunflower oil) for 5 days and the S9
fraction and S9 mix were prepared following the procedure of
Maron and Ames [26]. S9 fraction (microsome fraction) was pre-
pared and immediately distributed to small plastic tubes at 1 mL
quantity and then stored at ꢂ35 °C. The S9 mix was prepared fresh
for each mutagenicity assay. For preparation of S9 mix, one S9 tab-
let dissolved in 18 mL of sterile bidistilled water supplemented
with 2 mL of microsome fraction; 0.5 mL of S9 mix was used for
each plate. S9 mix contains microsome fraction, NADP, G-6-P and
other salt solutions [26,27].
1
H NMR spectrum of the ligand
Evidence of the bonding mode of sbH was also provided by the
H NMR spectrum of the azo–azomethine ligand. The 1H NMR
1
spectrum of the compound was obtained in deuterated dimethyl-
sulfoxide solution at room temperature using TMS as an internal
standard. The H NMR spectrum of the sbH ligand was given in
1
Fig. 1, and the chemical shifts of the different types of protons in
1
the H NMR spectrum of sbHꢁH
2
O ligand are also listed in Table 1.
The tautomeric azo-imine form of the sbH azo–azomethine dye is
1
1
indicated by H NMR spectroscopy. The H NMR spectrum of sbH
ligand showed a singlet signal at d 12.25 ppm, which was attrib-
uted to phenolic AOH proton (7a) [29]. The proton of the amide
group (ACOANHAN@C) of the ligand (10a) appears also as a sin-
glet at 12.01 ppm. It is well known that hydrogen bonded OH pro-
ton resonance appears at a lower field than that of NH proton
resonance [30]. Therefore, it may be concluded that the dye exists
in the azo-imine tautomeric form in DMSO solution. The ligand
also showed one singlet at d 8.80 ppm which was attributed to
Bacterial strains
ꢂ
Histidin deficient (his ) tester strains TA98 and TA100 of Salmo-
nella typhimurium were kindly provided by J.L. Swezey, Curator,
ARS Patent Culture Collection, Microbial Genomics and Bioprocess-
ing Research Unit, North University Street, Peoria, Illinois 61604,
USA. The TA100 strain is used for the detection of base-pair substi-
tution mutagens and TA98 strain is used for the detection of frame-
shift mutagens. Each strain before use in the assay was checked for
the presence of strain-specific marker as described Maron and
Ames [26].
1
the azomethine proton (8a) [31,32]. The H NMR spectrum of the
ligand revealed a singlet at d 8.34 ppm, corresponding to proton
of aromatic structure linked nitrophenylazo group (3a). The spec-
trum of sbH showed peaks at d 8.43 (d, 17a and 19a), d8.08 (d,
Mutagenicity assay
Standard procedure of plate incorporation assay was carried out
by using TA98 and TA100 strains for examining the frameshift
mutagens and base-pair substitution mutagens, respectively. Using
both strains, the Ames test was performed with metabolic activa-
tion (+S9 mix) to obtain a first approximation of mammalian
metabolism, and without metabolic activation (ꢂS9 mix). The
assay was carried out according to published paper [28]. TA98
and TA100 strains were exposed to a range of concentrations of
each test substance in a soft agar overlay. The number of revertants
observed in each concentration of test substances and in spontane-
ous control were scored.
1
6a and 20a), d7.97 (d, 22a and 26a), d7.96 (d, 5a), d7.63 (t, 23a
and 25a), d7.55 (t, 24a) and d7.07 (d, 6a) which are attributed to
aromatic hydrogens. Additionally, there is also water protons of
the solvent (d
6
-DMSO) and the sample observed at d3.33 ppm
[
33]. The presence of water in the structure was also confirmed
by IR spectroscopy and elemental analysis. These results are in
agreement with the literature [18].
IR spectra
2
The IR spectra of the tridentate sbHꢁH O ligand and its com-
plexes have been studied in order to characterize their structures.
The characteristic IR data of the azo–azomethine ligand and its
metal complexes are given in the experimental section. The com-
parison of IR spectra of the compounds imply that the ligand,
sbH, is monobasic tridentate in nature with carbonyl-oxygen, azo-
methine-nitrogen and phenolic-oxygen as the coordination sites.
In the ligand and complexes spectra, both ligand and complexes
Statistical significance
The observed differences between the test substances and con-
trol groups (spontane control and positive control) were analyzed
by t-test. Regression and correlation tests were used for dose–
response relationships.
ꢂ1
ꢂ1
Results and discussion
exhibit bands at 3400–3425 cm and 3085–3115 cm that are
assignable to (OH) and (ArACAH) [31,34]. Disappearance of
m
m
Synthesis
the broad band due to H-bonded phenolic OAH stretching in the
spectra of metal complexes confirmed the coordination of phenolic
oxygen atom to metal ions. The broad band centered at 3200–
The results of the elemental analyses of the ligand and its com-
plexes are in agreement with the chemical formulae. The azo-Schiff
base ligand N’-[{2-hydroxy-5-[(4-nitrophenyl)diazenyl]phenyl}meth-
ꢂ1
3275 cm in the free ligand can be assigned to the amide ANAH
stretching, which remains unaltered in the complexes [35]. This
suggests that the non-participation of amide NH group in coordi-
ylidene]benzohydrazidemonohydrate, sbHꢁH
2
O was synthesized in
ꢂ1
good yields in EtOH. The ligand is stable at room temperature and
soluble in common organic solvents such as DMSO, DMF, EtOH and
MeOH. The complexes are also stable at room temperature. Based
on the elemental analyses, spectroscopic characterization, these
mononuclear complexes are presumed to have the coordination
nation. The band at 1545 cm is due to the vibration of the azome-
thine group (ACH@NA) of the ligand [36]. This band in the metal
complexes shifted to higher frequencies as a result of coordination
of the azomethine nitrogen atom to the metal ion. The C@O
ꢂ1
observed at 1650 cm in the spectrum of the ligand showed a

Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
217
Fig. 1. The 1H NMR spectrum of the azo–azomethine (sbH) ligand in d
6
-DMSO.
HO
O
N
O
N
N
O
N
N
NH
N
H
NH
O
+
-
O
N
+
-
Tautomer (1b)
N
Tautomer (1a)
azo-enol-imine
O
hydrozone-ketone-imine
HO
O
O
O
OH
N
N
N
NH
NH
N
N
N
O
O
+
+
-
N
N
O
Tautomer (1d)
azo-ketone-enamine
Tautomer (1c)
azo-enol-imine
-
O
Scheme 2. Tautomeric forms of the sbH ligand.
ꢂ1
ꢂ1
downward shift to 1618–1610 cm in all the complexes indicat-
ing the coordination through the carbonyl oxygen [37].
bands observed at 1070–1095 cm are assigned to NAO stretch-
ing vibrations of the dye and its metal chelates. In addition to
the above bands all the complexes display the new bands in the
Hence, from the infrared spectroscopic data, it is inferred that
azomethine nitrogen, carbonyl and phenolic oxygen atoms are
involved in the coordination with transition metal ion in all com-
ꢂ1
far infrared region 615–730 and 515–520 cm were assigned to
(MAO) and m(MAN) vibrations, respectively [39]. These data are
in agreement with those previously reported for similar
m
ꢂ1
plexes. The peak appearing in the region 1475–1489 cm is attrib-
uted to (AN@NA stretching vibration) [34,38]. The absorption
compounds.

2
18
Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
-
O
NH
O
+
+
N
N
O
-
O
N
O
O
N
N
N
M
O
N
N
O
.
nH O
HN
2
M = Co(II) (m = 4), Ni(II) (n = 1), Cu(II) (n = 4), Zn(II) (n = 1), Cd(II) (n = 1)
Fig. 2. The proposed structure of the metal complexes.
Table 1
ligand and its metal complexes are summarized in Table 2. The
UV–Vis spectra of the azo-Schiff Base ligand containing AN@NA
chromophore and its metal complexes in DMSO showed two or
three absorption bands between 235 and 340 nm, as shown in
The 1H NMR data (ppm) of the azo–azomethine (sbHꢁH
O) ligand in d
2
6
-DMSO.
-
O
O
+
2
8
29
N
Figs. 3 and 4, respectively. The first band is referred to the
2
7
⁄
p
?
p
transitions of the aromatic, azomethine or AN@NA groups.
1
8
⁄
H
H
1
7
The second band ranged 320–340 nm is due to n ?
p
transition in
19a
17a
the azomethine system [40]. The longer wavelength band at 395–
19
⁄
4
05 nm can be assigned to n ?
p
transition in the AN@NA chro-
16
mophore group of the ligand and its metal chelates [41]. The bands
at 500 nm and 535 nm in the spectra of the Zn(II) and Cd(II) com-
plexes, respectively can be also assigned to an intra-molecular
charge transfer interaction. In addition to that, the electronic spec-
tra of the Co(II), Ni(II) and Cu(II) complexes exhibited a band at
510, 530 and 487 nm, respectively. These bands are assigned to
d–d transition in the complexes. These bands are characteristic of
octahedral complexes.
20
H
H
15
20a
16a
N
14
N
1
3
.
H O
2
4
H
H
3
5
a
3a
O
H
5
1
2
22a
2
11
N
H
2
1
6
9
22
23a
H
N
1
8
23
5
6
a
10
Computational studies
24
O
H
H
7
8a
10a
26
H
H
H
The optimized structures and vibrational frequencies of tautomers
The possible tautomers of the synthesized azo–azomethine dye
are optimized at B3LYP/6-31++G(d,p) level in vacuum. The opti-
mized structures of these tautomers are represented in Fig. 5.
These tautomers exist together in solution media but one of these
tautomers is the most stable. The most stable tautomer can be
determined as theoretically by taking into account total energy
2
7a
26a
24a
H
25a
Chemical shifts, dTMS (ppm)
Assignmentsa
J (Hz)
1
1
2.25
2.01
[s,1H] (7a)
[s, 1H] (10a)
[s, 1H] (8a)
[d, 2H] (17a, 19a)
[s, 1H] (3a)
[d, 2H] (16a, 20a)
[d, 2H] (22a, 26a)
[d, 1H] (5a)
[t, 2H] (23a, 25a)
[t, 1H] (24a)
[d, 1H] (6a)
[water-H]
[DMSO-H]
–
–
–
9.11
–
8.87
7.05
7.18
7.32
7.59
8.85
–
8
8
8
8
7
7
7
7
7
3
2
.80
.43
.34
.08
.97
.96
.63
.55
.07
.33
.51
(ETotal), enthalpy (H) and Gibbs free energy (G°) values which are
thermochemical parameters. Total energy, enthalpy and Gibbs free
energy include the zero-point energy and thermal corrections. The
mentioned parameters are represented in Table 3. According to the
ETotal, H and G°, ranking of tautomer stability should be as follow:
Table 2
–
UV–Vis. (nm) data of the synthesized ligand and its metal complexes in DMSO.
a
s: singlet; d: doublet and t: triplet.
Absorption
kmax (nm)
⁄
⁄
⁄
Compound
p
?
p
n ?
p
n ?
p
/CT
d ? d
(
(
(
1) sbHꢁH
2) [Co(sb)
3) [Ni(sb)
2
O
235
240
240
240
240
240
320
334
320
320
320
320
405
400
400
395
395/500
395/535
–
Electronic spectra
2
]ꢁ4H
]ꢁH
]ꢁ4H
]ꢁH
]ꢁH
2
O
O
2
O
O
ꢂ510
530
487
–
2
2
The electronic absorption spectra of the azo–azomethine ligand
and its complexes (I–VI) were obtained in 10 M DMSO solutions
at room temperature. The UV–Vis spectral data of the synthesized
(4) [Cu(sb)
2
ꢂ3
(
(
5) [Zn(sb)
6) [Cd(sb)
2
2
2
2
O
–

Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
219
Fig. 3. The UV–Vis. spectrum of the ligand in DMSO.
Fig. 4. The UV–Vis. spectrum of the Ni(II) complex in DMSO.
Fig. 5. Optimized structures of tautomers at B3LYP/6-31++G(d,p) level of theory in gas phase.
Table 3
Calculated thermochemical parameters (a.u.) of tautomers.
Tautomers
E
Total
H
G°
Table 4
The calculated quantum chemical parameters at B3LYP/6-31++G(d,p) level.
Tautomer (1a)
Tautomer (1b)
Tautomer (1c)
Tautomer (1d)
ꢂ1345.387474
ꢂ1345.379271
ꢂ1345.370056
ꢂ1345.369709
ꢂ1345.386529
ꢂ1345.378326
ꢂ1345.369111
ꢂ1345.368764
ꢂ1345.471405
ꢂ1345.463065
ꢂ1345.455051
ꢂ1345.454677
Labelsa
Pk(N + 1)
Pk
Pk(Nꢂ1)
+
s (eV )
ꢂ1
f
k
N1
N2
O1
O2
O3
O4
7.33995
7.20424
8.52528
8.31699
8.27064
8.28935
7.44731
7.31265
8.61746
8.70903
8.42426
8.42537
7.44414
7.26149
8.59768
8.45201
8.37641
8.37739
ꢂ0.10736
ꢂ0.10841
ꢂ0.09218
ꢂ0.39204
ꢂ0.15362
ꢂ0.13602
0.00179
0.02892
0.01118
0.14531
0.02705
0.02713
(
1a) > (1b) > (1c) > (1d). The tautomer with the lowest energy has
the most stabile structure. According to this ranking, the most sta-
ble tautomer is tautomer (1a). Infrared spectrum of the tautomer
1a) is calculated and the vibration frequencies are scaled by using
a
(
Atomic labels are defined in Fig. 2.

2
20
Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
Fig. 6. The MEP diagram of deprotonated form of tautomer (1) at B3LYP/LANL2DZ level.
Fig. 7. Optimized structure of [Co(sb)
phase.
2
] complex at B3LYP/LANL2DZ level in gas
2
Fig. 8. Optimized structure of [Ni(sb) ] complex at B3LYP/LANL2DZ level in gas
phase.
ꢂ1
0
.95. Some vibration frequencies (cm ) are obtained as: 3633
(
OAH), 3038 (ArACAH), 1240 (CAO), 1586 (C@N), 1459 (N@N),
1
066 (NAO).
These frequencies and their experimental values are subjected
to linear regression analysis. Correlation constant of this analysis
is found as 0.9913. According to this result, there is a good
agreement between experimental and calculated frequencies.
The local reactivity
The active center of deprotonated tautomer (1a) can be deter-
mined by using local softness and Fukui functions of atoms in mol-
ecule. Deprotonated form of tautomer (1a) is optimized at B3LYP/
6
-31++G(d,p) level in gas phase. Local softness (s) and nucleophilic
+
k
attack (f ) which is the Fukui function are calculated with Eqs. (1)
and (2) [42,43].
2
s ¼
ꢄ ½P
k
ðNÞ ꢂ P
k
ðN ꢂ 1Þꢃ
ð1Þ
ð2Þ
ðELUMO ꢂ EHOMO
þ
Fig. 9. Optimized structure of [Cu(sb) ] complex at B3LYP/LANL2DZ level in gas
2
f
¼ P
k
ðN þ 1Þ ꢂ P ðNÞ
k
k
phase.

Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
221
Table 6
ꢂ1
Calculated vibration frequencies (cm ) at B3LYP/LANL2DZ level at gas phase and
correlation constant (R ) values.
2
m
CAH (Arom.)
m
C@N
m
N@N
m
NAO
m
MAO
m
MAO
R2
[
[
[
[
[
Co(sb)
2
]
]
3107
1583
1552
1531
1528
1528
1343
1439
1442
1423
1448
1080
1080
1080
1080
1080
664
662
749
644
642
516
520
519
545
542
0.9941
0.9993
0.9994
0.9988
0.9995
Ni(sb)
Cu(sb)
2
31145
3093
3094
3107
2
]
]
Zn(sb)
Cd(sb)
2
2
]
P
k
(N), P
k
(Nꢂ1), Fukui function for nucleophilic attack and local soft-
ness are given in Table 4 for some donor atoms in tautomer (1a).
There are many donor atoms in tautomer (1a). This tautomer is
three-dentate ligand that is proven experimentally in this study.
2
Fig. 10. Optimized structure of [Zn(sb) ] complex at B3LYP/LANL2DZ level in gas
phase.
Fukui function and local softness can be used for determining the
+
most active atom towards metal atoms. According to the f
k
+
and s, the most active atom is O2 atom (f
k
= ꢂ0.39204 and
s = 0.14531). Therefore, tautomer (1a) uses the O2 atom when
bonding with metal. After that, coordinate-covalent bond is formed
between N2 and metal. If the bonding is formed from O3 or O4
atom, structure of complex will be very strained. Therefore, metal
prefers the bonding from N2 atom. Finally, the bond is formed
between metal and O1. This evaluation is proven by using Fukui
functions and local softness.
Molecular electrostatic potential (MEP) diagram for deproto-
nated form of tautomer (1) is mapped up at the level of B3LYP/
LANL2DZ theory with optimized geometry. The MEP diagram of
tautomer (1a) is represented in Fig. 6. The positive (blue) and neg-
ative (red) regions of MEP are related to electrophilic and nucleo-
philic reactivity, respectively. In the MEP diagram of
deprotonated form of tautomer (1a), the most negative regions
are represented as zones 1, 2 and 3. In zones 1 and 2, the negative
regions are mainly localized on oxygen atoms. As for the zone 3,
2
Fig. 11. Optimized structure of [Cd(sb) ] complex at B3LYP/LANL2DZ level in gas
phase.
nitrogen atom is activated by
p electrons.
where P
k
(N + 1), P
k
(N) and P
k
(Nꢂ1) are the charges of the atoms on
The optimized structures and vibration frequencies of complexes
Optimized structures of [Co(sb) O, [Ni(sb) ]ꢁH
]ꢁ4H
Cu(sb) O, [Zn(sb) ]ꢁH O and [Cd(sb) ]ꢁH O are calculated at
]ꢁ4H
B3LYP/LANL2DZ level in gas phase and given in Figs. 7–11,
the systems with N + 1, N, Nꢂ1 electrons. EHOMO and ELUMO are the
2
2
2
2
O,
highest occupied molecular orbital energy and the lowest
[
2
2
2
2
2
2
k
unoccupied molecular orbital energy, respectively. The P (N + 1),
Table 5
Calculated geometrical parameters of relevant complexes at B3LYP/LANL2DZ level.
Bond lengths (Å)
[Co(sb)
2
]ꢁ4H
2
O
[Ni(sb)
2 2
]ꢁH O
[Cu(sb)
2
]ꢁ4H
2
O
[Zn(sb)
2
]ꢁH
2
O
[Cd(sb)
2
]ꢁH
2
O
MAN1
MAN2
MAO1
MAO2
MAO3
MAO4
1.932
1.913
2.217
2.071
1.966
2.069
1.904
1.884
2.318
2.680
1.964
1.876
1.991
1.988
2.278
2.067
2.063
2.275
2.187
2.186
2.198
2.030
2.028
2.199
2.407
2.406
2.353
2.207
2.206
2.355
Bond Angles (deg.)
N1AMAN2
N1AMAO1
N1AMAO2
N1AMAO3
N1AMAO4
N2AMAO1
N2AMAO2
N2AMAO3
N2AMAO4
O1AMAO2
O1AMAO3
O1AMAO4
O2AMAO3
O2AMAO4
O3AMAO4
177.4
176.4
88.4
72.0
93.0
89.5
91.7
107.2
83.4
93.7
157.0
82.3
176.5
173.4
74.1
83.6
100.7
101.0
101.0
100.6
83.6
74.1
156.4
90.9
86.7
100.5
90.5
172.2
68.9
77.1
107.9
105.4
105.2
108.0
77.1
68.9
145.4
93.7
90.0
102.8
93.0
79.9
91.1
89.7
95.8
98.6
90.2
92.4
81.9
170.0
88.4
88.8
96.0
87.8
173.2
77.6
89.4
92.6
99.8
99.8
92.7
89.5
77.6
163.4
86.0
86.5
105.2
85.5
163.8
104.2
86.8
87.9
173.1
156.7
145.5
M: Metal atom.

2
22
Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
Table 7
The calculated dipole moment (l), polarizability (a) and hyperpolarizability (b) for tautomer (1a) and mentioned complexes.
Tautomer (1a)
[Co(sb)
2
] (1)
[Ni(sb)
2
] (2)
[Cu(sb)
2
] (3)
[Zn(sb)
2
] (4)
2
[Cd(sb) ] (5)
a
a
l
l
l
a
a
a
a
a
a
b
b
b
b
b
b
b
b
b
x
2.5241
0.8945
0.1052
578.6714
37.1451
391.4924
ꢂ9.4018
ꢂ6.6612
151.3945
ꢂ7997.9198
ꢂ4802.7735
ꢂ2406.7417
ꢂ503.3435
ꢂ158.4538
ꢂ52.2101
ꢂ37.0283
28.8360
ꢂ0.4626
ꢂ0.6936
0.5520
422.2826
11.6574
398.8246
33.8563
6.0494
425.2902
ꢂ235.8349
212.1989
147.6071
185.0239
69.2882
10.0966
103.4493
42.1253
ꢂ73.7760
0.9999
ꢂ1.8366
ꢂ0.0501
ꢂ0.0971
ꢂ0.0658
y
4.7695
6.5039
7.6533
7.4593
a
z
1.6661
ꢂ0.0188
ꢂ0.0683
ꢂ0.06278
1334.3890
11.8295
768.3616
40.9989
b
xx
1556.5790
ꢂ0.8052
1414.8938
11.8583
1294.3750
10.6425
b
yy
b
zz
539.6064
24.6240
713.5822
6.6718
788.8305
22.9897
ꢂ7.8733
b
xy
b
xz
yz
ꢂ7.0106
ꢂ10.9065
582.0254
ꢂ484.7714
ꢂ29182.4491
84.4034
ꢂ4081.5522
ꢂ127.5076
4.914.8745
83.9897
141.0069
1117.5799
6.5042
105.7215
2.60 ꢄ 10
ꢂ6.7427
b
591.1687
1906.2346
ꢂ24436.9930
ꢂ1499.4045
ꢂ673.3176
ꢂ3605.4751
3874.3861
ꢂ800.4356
970.4951
804.0116
5.3757
544.5088
ꢂ351.7793
ꢂ27187.5160
185.8050
ꢂ2678.5204
ꢂ277.3544
4645.1822
ꢂ5.2386
546.2184
ꢂ420.2525
ꢂ26289.1500
250.0008
ꢂ1046.5988
ꢂ305.6399
4268.1874
26.2933
b
b
xxx
yyy
b
zzz
b
xyy
b
xxy
b
xxz
b
b
b
xzz
yzz
ꢂ36.2375
2550.7871
7.6543
103.4253
2.47 ꢄ 10
ꢂ72.7850
2899.2310
7.4599
104.4493
2.40 ꢄ 10
yyz
a
13.7035
2.6800
49.7589
8.78 ꢄ 10
l
c
a
b
41.1343
2.92 ꢄ 10
103.5010
2.36 ꢄ 10
d
ꢂ26
ꢂ27
ꢂ25
ꢂ25
ꢂ25
ꢂ25
a
b
c
In Debye.
In atomic unit (a.u.).
3
In Å .
In cm /esu.
d
5
Fig. 12. The graphs of polarizability and hyperpolarizability for the mentioned compounds and urea.
respectively. Calculated structural parameters of mentioned com-
plexes are given in Table 5. According to Table 5, there are six
bonds around the metal atoms. As theoretically, the radii of metal
ions decrease as follows in strong field:
optical devices [44]. The NLO properties increase with conjugation
of electrons or adding donor/acceptor groups to molecule. Polar-
izability ( ) and hyperpolarizability (b) can be used to describe the
p
a
relationship between the electronic structures of molecules and
their NLO properties. The polarizability and hyperpolarizability
2
þ
2þ
2þ
2þ
2þ
Cd > Zn > Cu > Ni > Co
increase with increasing the delocalization of
p electrons. There-
2
+
fore, the NLO properties increase with increasing polarizability
and hyperpolarizability. NLO properties of tautomer (1) and men-
tioned complexes are studied with DFT/B3LYP method.
Electron density around the nucleus is the maximum in Cd ion
while is the minimum in Co2+ ion. Therefore, bond lengths mainly
increase with increasing the radii of metal ions. The same bond
lengths and angle values are mainly similar in each complex.
No imaginary frequencies were found in calculations for rele-
vant complexes. Calculated vibration frequencies and correlation
constants (R ) between calculated and experimental frequencies
are given in Table 6. There is a good correlation between experi-
mental frequencies and their calculated results.
The total static dipole moment (
ability (
l
), the average linear polariz-
a
) and first hyperpolarizability (b) are calculated by using
Eqs. (3)–(5), respectively [44].
2
qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi
2
2
2
l
a
¼
¼
l
þ
l
þ
l
ð3Þ
x
y
z
1
3
ð
a
xx
þ
a
yy
þ
a
zz
Þ
ð4Þ
2
2
The non-linear optical properties
b ¼ ½ðbxxx þ bxyy þ bxzzÞ þ ðbyyy þ bxxy þ byzzÞ
Non-linear optical properties (NLO) are current research field
because of its importance in providing the key functions of fre-
quency shifting, optical modulation, optical switching, optical logic
and optical memory. Therefore, the NLO properties play an impor-
tant role for design of materials in communication technology and
2 1=2
þðbzzz þ bxzz þ byzzÞ ꢃ
ð5Þ
Calculated polarizability and hyperpolarizability of mentioned com-
pounds were presented in Table 7. In many theoretical studies, urea
is taken into account as reference substance. The polarizability and

Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
223
X-ray powder diffraction analysis
Growth of single crystals of azo–azomethine compounds failed,
so they were characterized by XRD [46,47]. X-ray powder diffrac-
tion analysis of the sbH ligand and its metal complexes was carried
out to understand the type of crystal system, lattice parameters
and the cell volume. As shown in Fig. 13 the XRD patterns indicate
crystalline nature for the sbH ligand and its metal complexes.
Indexing of the diffraction patterns were performed using High-
Score Plus software. For example, for the Cd(II) and Ni(II) com-
plexes, their Miller indices (h k l) along with observed and
calculated 2h angles, d values and relative intensities were given
in Tables 8 and 9. Also, from the indexed data the unit cell param-
eters were calculated and listed in Table 10. The powder XRD pat-
terns of the compounds are completely different from those of the
starting materials, demonstrating the formation of coordination
compounds. It is found that sbH ligand, Cd(II), and Zn(II) complexes
have monoclinic structure, while Co(II), Cu(II), and Ni(II)
complexes have orthorhombic structure. The crystal structures of
similar type of samples were reported as monoclinic and ortho-
rhombic [48,49]. Also, in order to investigate the crystalline infor-
mation of the all samples, the crystallite sizes D were calculated
from the most intense peaks using Sherrer’s formula [50]. The
calculated results are given in Table 10.
(
f)
(
e)
(
d)
(
c)
(
b)
(
a)
2
0
30
40
50
60
2
Theta [degree]
Fig. 13. The XRD diffraction patterns of (a) (sbHꢁH
2
O), (b) [Cd(sb)
]ꢁH
2
]ꢁH
O.
2
O, (c)
Ames mutagenicity test results
[
Co(sb) O, (d) [Cu(sb) ]ꢁ4H O, (e) [Ni(sb) ]ꢁH O and (f) [Zn(sb)
2
]ꢁ4H
2
2
2
2
2
2
2
sbHꢁH
2
O, the presence and absence of metabolic activation sys-
tem for mutagenic strains TA98, while TA100 strain in the same
3
hyperpolarizability values of this substance are equal to 3.8312 Å
and 0.37289 ꢄ 10
ꢂ30
5
cm /esu, respectively [45]. The polarizability
medium did not show such an effect. [Cu(sb) ]ꢁ4H O, the presence
2
2
and hyperpolarizability values of mentioned compounds and refer-
ence substance are plotted in Fig. 12. According to Fig. 12, the polar-
izability and hyperpolarizability of tautomer (1a) and complexes are
greater than urea. This result means that tautomer (1a) and men-
tioned complexes have NLO properties. The polarizability and
hyperpolarizability of complex 3, which is [Cu(sb) ], are higher than
2
the others. Therefore, this complex has the most effective NLO
properties.
and absence of metabolic activation system for TA98 strain showed
a strong mutagenic effect, in the same environment. TA100 strain
showed the highest concentration of a mutagenicity. [Ni(sb) ]ꢁH O,
2
2
the presence and absence of metabolic activation system for TA98
strain showed a strong mutagenic effects, TA100 strains only at the
highest concentration in the presence of metabolic systems has
shown mutagenic effects. Moreover, the presence and absence of
metabolic system TA98 strain revertants dose-dependently
Table 8
XRD data of the [Cd(sb)
2 2
]ꢁH O metal complex.
0
0
P. no.
h
k
l
2Th.(o) (°)
2Th.(c) (°)
Rel. Int. (%)
d-sp.(o) ( AÅ )
d-sp.(c) ( ÅA )
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
2
1
2
1
0
2
2
1
3
3
1
3
3
2
5
5
5
5
3
0
4
5
6
4
8
8
0
1
0
1
0
1
0
1
1
0
2
0
1
0
0
0
1
0
2
2
2
2
1
0
0
2
0
0
1
11.8411
13.2269
14.9159
15.508
11.8325
13.2404
14.8879
15.5282
16.8389
18.4929
20.1028
21.73
7.467796
6.688346
5.93459
7.473225
6.681538
5.945692
5.701929
5.260922
4.793962
4.413511
4.086568
3.915726
3.717257
3.623313
3.525276
3.327921
3.112142
2.91646
2.836208
2.775292
2.660365
2.634648
2.556646
2.396981
2.33378
21.12
20.74
9.77
27.6
13.54
19.93
32.01
48.52
6.55
7.32
10.77
19.38
100
ꢂ1
5.709305
5.265467
4.793204
4.406921
4.093177
3.922064
3.714706
3.630775
3.532636
3.318366
3.111933
2.916511
2.836566
2.771194
2.668363
2.631551
2.557538
2.396895
2.335171
2.196981
2.098629
1.86841
2
16.8243
18.4958
20.1332
21.6945
22.6532
23.9359
24.4977
25.1893
26.8453
28.6629
30.6289
31.5143
32.2777
33.5577
34.0413
35.0579
37.492
ꢂ1
ꢂ2
2
ꢂ1
ꢂ2
0
22.6904
23.9193
24.549
1
1
1
1
1
1
1
1
1
1
2
2
2
2
2
2
2
2
25.2428
26.7667
28.6609
30.6295
31.5184
32.2288
33.6616
34.0001
35.0705
37.4907
38.5454
41.0425
43.0561
48.6986
55.2061
ꢂ2
3
4.9
ꢂ1
1
0
ꢂ2
ꢂ2
ꢂ3
ꢂ2
0
4.74
4.79
6.7
5.54
4.22
10.42
11.11
6.37
3.4
38.5216
41.0501
43.0674
48.6957
55.2202
ꢂ2
2.197372
2.099154
1.868306
1.66248
4
7.13
1.47
1.75
0
ꢂ1
1.662089

2
24
Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
Table 9
XRD data of the [Ni(sb)
2
]ꢁH
2
O metal complex.
0
0
P. no.
h
k
l
2Th.(o) (°)
2Th.(c) (°)
Rel. Int. (%)
d-sp.(o) ( AÅ )
d-sp.(c) ( ÅA )
1
2
3
4
5
6
7
8
9
0
1
2
3
4
5
6
7
0
1
0
1
2
0
0
1
3
3
1
2
3
3
0
5
2
1
1
0
0
1
1
2
2
1
0
1
1
0
1
3
0
0
0
0
2
2
0
2
0
0
0
2
3
3
3
3
2
2
5
10.5948
12.5023
14.9573
16.5643
17.2678
18.4672
21.1189
22.1933
23.0139
25.402
25.9504
28.5993
30.7165
32.4683
35.5084
37.5697
40.7798
10.5278
12.516
15.0712
16.5297
17.168
18.4193
21.1458
22.2206
22.9581
25.4145
25.9936
28.5919
30.6575
32.4994
35.5015
37.5957
40.7734
8.343335
7.074296
5.918257
5.347516
5.131216
4.800557
4.203414
4.002285
3.861404
3.503536
3.430729
3.118707
2.908392
2.755362
2.526113
2.392119
2.21092
8.396242
7.066612
5.873757
5.358649
5.160823
4.812942
4.198121
3.997433
3.870655
3.501848
3.425126
3.119501
2.913863
2.752802
2.526591
2.390527
2.211248
16.89
13.36
53.78
10.94
32.5
22.83
6.41
10.79
3.57
30.23
100
9.94
2.73
2.8
3.33
3.01
1
1
1
1
1
1
1
1
4.18
Table 10
XRD parameters of the sbH ligand and its metal complexes.
Sample Lattice parameters
Volume (Å3)
Crystallite size D (nm)
Crystal system
a (Å)
b (Å)
c (Å)
b (°)
(
(
(
(
(
(
1) (sbHꢁH
2
O)
]ꢁ4H
]ꢁH
]ꢁ4H
]ꢁH
]ꢁH
20.0986
22.6700
13.0821
12.2197
13.9605
14.9687
4.8815
10.3893
8.4076
10.8324
14.8258
7.4861
16.0517
8.2069
11.7446
5.7546
8.9747
10.5176
121.2430
90
90
90
121.7830
92.9437
1346.46
1932.94
1291.77
761.73
1579
36
49
93
27
93
118
Monoclinic
2) [Co(sb)
2
2
O
O
Orthorhombic
Orthorhombic
Orthorhombic
Monoclinic
3) [Ni(sb)
4) [Cu(sb)
2
2
2
2
O
5 [Zn(sb)
6) [Cd(sb)
2
2
O
2
2
O
1177.02
Monoclinic
4
3
3
2
2
1
1
0
5
0
5
0
5
0
5
0
2
1
1
1
1
00
80
60
40
20
y = 30,762x - 6,328
r = 0,9838
y = 4,4191x + 9,8113
r = 0,9781
100
8
6
4
2
0
0
0
0
0
1
2
3
4
5
6
Doses
Fig. 14. Dose-dependently increase in the mutagenic activity of [Ni(sb)
TA98 strain in the absence of metabolic activation system.
2
]ꢁH
2
O on
1
2
3
4
5
6
Doses
3
3
2
2
1
1
5
0
5
0
5
0
5
0
Fig. 16. Dose-dependently increase in the mutagenic activity of [Co(sb)
TA98 strain in the presence of metabolic activation system.
2
]ꢁ4H
2
O on
increased the percentage of colonies (Fig. 14, r = 0.9781; Fig. 15,
r = 0.9732).
[
Co(sb)
2
]ꢁ4H
2
O, in the presence of metabolic activation system
y = 3,614x + 11,053
r = 0,9732
and in the absence , both in TA98 and TA100 strain showed very
strong mutagenic effects. On the other hand in the presence of
S9 TA98 strain number of revertants dose-dependently increased
the number of colonies (Fig. 16, r = 0.9732).
[
Zn(sb)
2
]ꢁH
2
O, in the presence of metabolic activation system
for TA100 strains did not show any mutagenic effect, strain TA98
in the absence of the metabolic systems has shown mutagenic
1
2
3
4
5
6
Doses
effects. [Cd(sb)
2
]ꢁH
2
O, in the presence and absence of metabolic
activation system for TA98 strain showed weak mutagenic activity,
TA100 strain did not show any mutagenic activity (Table 11).
Fig. 15. Dose-dependently increase in the mutagenic activity of [Ni(sb)
TA98 strain in the presence of metabolic activation system.
2
]ꢁH
2
O on

Sß . Bitmez et al. / Journal of Molecular Structure 1076 (2014) 213–226
225
Table 11
The mutagenicity of ligand and its metal complexes in Salmonella typhimurium TA98 and TA100 strains in the absence (-S9) or presence (+S9) of S9 mix.
Test substances
Concentrat.mg/plate
TA98
TA100
ꢂS9
+S9
ꢂS9
+S9
Spontaneous control
NPD
–
200
20
1
11.67 ± 2.51
3025 ± 172
12.50 ± 1.93
106.7 ± 12.9
103.00 ± 9.57
l
l
g/ml
g/ml
g/ml
2
-AF
3510 ± 247
743.2 ± 38.2
SA
l
651.8 ± 48.5
*
*
*
*
*
**
***
*
sbHꢁH
2
O
0.80
31.00 ± 2.84
31.67 ± 4.23
31.67 ± 4.23
23.33 ± 3.03
25.67 ± 2.29
22.73 ± 1.65
26.17 ± 4.74
24.33 ± 3.62
14.69 ± 3.02
15.67 ± 3.51
95.5 ± 11.6
86.33 ± 4.07
92.17 ± 7.23
79.17 ± 4.56
51.83 ± 7.90
123.8 ± 14.7
121.5 ± 10.02
104.79 ± 4.67
99.3 ± 9.4
***
*
*
0.40
0.20
0.10
0.05
*
*
**
*
***
61.52 ± 4.90
*
*
*
**
**
**
**
***
***
*
**
[
[
[
[
[
Cu(sb)
2
]ꢁ4H
2
O
0.80
227.2 ± 43.6
190.5 ± 41.8
141.2 ± 18.0
63.6 ± 10.3
421.2 ± 83.5
322.5 ± 61.2
231.8 ± 57.9
237.3 ± 37.3
133.7 ± 16.0
273.9 ± 52.9
211.4 ± 48.3
123.8 ± 17.5
***
*
0.40
0.20
0.10
0.05
71.68 ± 8.07
**
64.0 ± 11.9
*
**
***
**
118.83 ± 6.04
56.00 ± 6.67
41.67 ± 6.59
103.50 ± 9.36
84.79 ± 7.45
*
**
*
129.3 ± 21.1
***
***
***
***
*
***
***
***
***
**
Ni(sb)
Co(sb)
Zn(sb)
2
]ꢁH
2
O
0.80
34.67 ± 2.29
32.50 ± 6.41
28.00 ± 3.62
24.33 ± 1.20
20.50 ± 2.57
32.67 ± 4.27
28.17 ± 3.42
25.00 ± 2.83
23.87 ± 1.67
20.00 ± 3.09
168.0 ± 12.5
144.7 ± 16.0
108.3 ± 24.9
98.8 ± 16.9
89.17 ± 4.68
120.09 ± 8.73
102.32 ± 8.19
94.3 ± 11.20
96.5 ± 13.4
0.40
0.20
0.10
0.05
*
79.2 ± 15.7
*
*
*
*
*
*
***
***
**
**
**
**
**
*
**
2
]ꢁ4H
2
O
0.80
26.50 ± 2.47
29.67 ± 2.58
27.67 ± 2.87
22.67 ± 2.16
20.50 ± 2.88
171.0 ± 16.7
143.5 ± 13.4
132.2 ± 18.7
28.83 ± 3.05
31.33 ± 4.12
28.17 ± 2.90
23.00 ± 2.07
17.83 ± 1.99
475.2 ± 96.0
**
*
***
0
0
0
0
.40
.20
.10
.05
490.5 ± 92.6
249.0 ± 32.6
199.6 ± 22.7
132.5 ± 13.9
**
*
*
**
84.0 ± 12.9
***
64.84 ± 5.42
*
*
*
*
**
***
***
***
***
2
]ꢁH
2
O
0.80
27.33 ± 3.19
30.17 ± 1.85
21.50 ± 1.84
15.83 ± 3.35
14.50 ± 1.61
14.57 ± 2.54
14.16 ± 1.92
13.34 ± 3.35
129.00 ± 4.14
134.00 ± 7.82
117.8 ± 11.9
108.33 ± 9.08
51.93 ± 4.90
49.17 ± 7.05
33.81 ± 4.80
27.50 ± 2.78
**
*
*
0
0
0
0
.40
.20
.10
.05
*
8.19 ± 1.32
*
**
**
6.57 ± 3.29
78.83 ± 6.18
39.2 ± 16.4
*
*
*
*
**
***
**
*
Cd(sb)
2
]ꢁH
2
O
0.80
36.33 ± 1.78
28.33 ± 5.17
15.33 ± 1.23
19.33 ± 2.54
14.33 ± 3.28
36.83 ± 2.33
31.67 ± 4.60
21.33 ± 2.70
19.00 ± 1.81
15.00 ± 2.37
121.17 ± 6.32
106.00 ± 7.35
95.17 ± 7.11
93.17 ± 5.51
**
0.40
0.20
0.10
0.05
90.33 ± 3.99
93.50 ± 7.98
**
*
*
74.0 ± 10.3
76.50 ± 5.79
*
**
*
59.00 ± 5.99
67.2 ± 10.9
NPD: 4-nitro-o-phenylenediamine, 2AF: 2-Aminoflourene, SA: Sodium azid.
*
P < 0.05.
*
*
P < 0.01.
**
*
P < 0.001.
Conclusion
In this work, azo (AN@NA) and nitro (ANO
On the other hand [Cu(sb)
2
]ꢁ4H
2
O and [Co(sb)
2
]ꢁ4H
2
O metal
complexes in the presence and absence of metabolic activation
system for TA100 strains have shown mutagenic activity, the
ligand and its metal complexes, statistically not significantly
2
) chromophore
groups containing azo–azomethine ligand, N’-[{2-hydroxy-5-[(4-
nitrophenyl)diazenyl]phenyl} methylidene]benzohydrazidemonohy-
increased. This situation [Cu(sb)
complexes and their metabolites induce point mutations the other
complexes and the ligand did not show such activity (Table 11) .
2
]ꢁ4H
2
O and [Co(sb)
2
]ꢁ4H
2
O metal
drate, (sbHꢁH
2
O) derived from 2-hydroxy-5-[(4-nitrophenyl)
diazenyl]benzaldehyde with benzohydrazide in EtOH and its some
transition metal chelates have been synthesized. The analytical
data and the spectroscopic studies suggested that the complexes
Acknowledgement
had general formula of [M(sb)
el(II), copper(II), zinc(II) or cadmium(II) ions. According to the UV–
Vis. and IR data of the nitrophenylazo linked Schiff base ligand,
2
]ꢁnH
2
O, where M is cobalt(II), nick-
This work was financially supported by the Unit of Coordination
of Scientific Research Projects, Kahramanmara sß Sütçü Imam
University, Kahramanmara ßs , Turkey (Project no: 2010/2-15YLS).
Also, the authors wish to thank Prof. Dr. Vickie McKee, Department
of Chemistry at Lougbrough University, Leichester, UK for H NMR
measurements.
sbHꢁH
2
O was coordinated to the metal ion through the azomethine
nitrogen (ACH@NA) and oxygen atoms of the hydroxyl (AOH) and
carbonyl (C@O) groups. From the XRD results, it is found that mbH
ligand, Cd(II), and Zn(II) complexes have monoclinic structure,
while Co(II), Cu(II), and Ni(II) complexes have orthorhombic struc-
ture. Based on the above results, the structure of the coordination
compounds under investigation can be formulated. All in all,
1
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