Co(II), Ni(II) and Cu(II) complexes of 1,4-di-(1-hydroxyimino-2-phenyl-2- oxo-ethylamino)benzene: Synthesis, characterization and thermal studies

Article abstract of DOI:10.1007/s10973-005-7112-y

The ligand has been prepared from ω-chloroisonitrosoacetophenone and 1,4-phenylenediamine in the presence of NaHCO₃. The ligand have a C=O group and an -NH-R group adjacent to the oxime group. The Ni(II), Cu(II) and Co(II) complexes of the synthesized ligand were prepared and their structures were identified using FTIR, UV-Vis spectral data, elemental analysis, thermal analysis and magnetic moment measurements. The metal-ligand ratios were found to be 3:2. The ligands were found to coordinate to the metal ions via the oxime nitrogen, oxime oxygen, one of the carbonyl group and amide nitrogen atoms. Thermal analyses data reveals that the water in the complexes was found to be non-coordinated to the metal ions. In the trinuclear structures, the metals have the tetrahedral environments.

Full text of DOI:10.1007/s10973-005-7112-y

Journal of Thermal Analysis and Calorimetry, Vol. 85 (2006) 2, 295–299
Co(II), Ni(II) AND Cu(II) COMPLEXES OF
,4-DI-(1-HYDROXYIMINO-2-PHENYL-2-OXO-ETHYLAMINO)BENZENE
Synthesis, characterization and thermal studies
1
1
M. Taê and H. BatÏ
*
2
1
Karadeniz Technical University, Giresun Faculty of Art and Sciences, Department of Chemistry, 28049 Giresun, Turkey
2
Ondokuz Mayis University, Art-Science Faculty, Department of Chemistry, 55139 Samsun, Turkey
The ligand has been prepared from ω-chloroisonitrosoacetophenone and 1,4-phenylenediamine in the presence of NaHCO
3
. The
ligand have a C=O group and an –NH–R group adjacent to the oxime group. The Ni(II), Cu(II) and Co(II) complexes of the synthe-
sized ligand were prepared and their structures were identified using FTIR, UV-Vis spectral data, elemental analysis, thermal analy-
sis and magnetic moment measurements. The metal-ligand ratios were found to be 3:2. The ligands were found to coordinate to the
metal ions via the oxime nitrogen, oxime oxygen, one of the carbonyl group and amide nitrogen atoms. Thermal analyses data re-
veals that the water in the complexes was found to be non-coordinated to the metal ions. In the trinuclear structures, the metals have
the tetrahedral environments.
Keywords: amide oxime, carbonyl oxime, oxime, thermal analysis, trinuclear complex
Introduction
In present work, a newly synthesized amido-car-
bonyl-oxime ligand which contains two oxime groups,
two carbonyl groups and two –NH-groups, and their
Ni(II), Cu(II), Co(II) complexes were studied.
Organic chelating ligands containing the –C=N–OH
group have been named as oxime compounds (Fig. 1a)
[1, 2]. Tscugaeff first introduced dimethylglyoxime as
a gravimetric reagent for nickel and since then oxime
ligands and their transition metal complexes have been
extensively studied [1–3]. Oximes derivatives are very
important compounds because of their biological activ-
ity, such as insecticidal, miticidal, nematocidal activi-
ties, antidote activities for organophosphor poison.
Some oxime complexes have anticancerogenic activi-
ties [4–6]. Oximes and their derivatives have also been
used in analytical applications, such as determination
and extraction of the metals [7–12].
Experimental
Materials
Synthesis of the 1,4-di-(1-hydroxyimino-
2-phenyl-2-oxo- ethylamino)benzene (LH4)
The ligand was prepared from the reaction of ω-chloro-
isonitrosoaceto-phenone [19] with 1,4-phenylene-
diamine (Scheme 1) and can be named alternatively as
1
-phenyl-2-[4-(1-hydroxyimino-2-phenyl-2-oxo-ethyl-
amino)phenylamino]-2-hydroxyimino ethane-1-one.
A solution of 0.015 mol 1,4-phenylenediamine
1.62 g) in EtOH (20 mL) was added dropwise to a so-
lution of ω-chloroisonitrosoacetophenone (0.030 mol,
.5 g) in EtOH, and then solid NaHCO (0.030 mol,
.52 g) was added to the mixture. After 4 h, H O
(
5
3
Fig. 1 Oximes and dioxime derivatives
2
2
(
20 mL) was added dropwise to the mixture. The pre-
Vic-dioxime (Fig. 1b), carbonyl-oxime (Fig. 1c),
amide-oxime ligands (Fig. 1d) and their metal com-
plexes have been studied extensively, but the work
done on amido-carbonyl-oximes (Fig. 1e), which
have –C=O and –NH–R’ groups in the same molecule
in vicinal position with oxime groups are rather few
cipitated product was filtered, washed with water and
cold EtOH and dried on air.
Ni(II), Cu(II), Co(II) complexes
The solutions of metal salts (3 mmol) (Ni(CH
COO)
3 2
[
13–18]. This type of compounds is a new research
·
4H O, Cu(CH COO) ·H O and Co(CH COO) ·4H O)
2 3 2 2 2
3
2
area on the oxime ligands and their complexes.
in 15 mL H O were added to a solution of the ligands
2
*
Author for correspondence: murattas@ktu.edu.tr
1
388–6150/$20.00
Akadémiai Kiadó, Budapest, Hungary
Springer, Dordrecht, The Netherlands
©
2006 Akadémiai Kiadó, Budapest

TAŸ, BATI
(3 mmol) dissolved in 30 mL EtOH. The color of the
ligand solutions were changed immediately from yellow
to black for complex formation. In order to isolate com-
plexes by precipitation, concentrated NH (0.1 mL)
3
were added. The precipitates were filtered, washed with
water and EtOH and dried on air. The colors, melting
points, molecular masses, magnetic measurements and
elemental analysis data are given in Table 1.
Methods
All starting materials were commercially available
1
and were reagent grade. The H–NMR spectra was re-
corded on a Bruker AC-200 FT-NMR spectrometer,
utilizing deuterated dimethylsulphoxide as a solvent
and TMS was used as an internal standard. IR spectra
Fig. 2 Suggested structure for Co(II), Ni(II) and Cu(II) com-
–
1
(
4000–200 cm ) were recorded on a Jasco-430 FTIR
plexes of the ligand
spectrophotometer with sample prepared as KBr pel-
lets. The magnetic moments of the complexes were
measured using a Sherwood scientific MX1 model
Gouy magnetic susceptibility balance at room tem-
perature. UV-Vis spectra were recorded with a
Unicam UV2 UV-Visible spectrometer in di-
methylsulphoxide solution. TG and DTA curves were
recorded simultaneously in static air atmosphere with
a Rigaku TG8110 thermal analyzer. The heating rate
of the ligand were synthesized by treating the ligand
and the metal salts in the presence of ammonia. The
general reaction for the formation of metal complexes
is shown below and their structures are given in Fig. 2.
2
+
+
2
LH +3M →[M (LH) ]+6H
4
3
2
where M=Ni(II), Cu(II) and Co(II).
The structures of the ligand and their complexes
1
have been verified by IR, UV-Vis, H NMR spectral
–
1
was 10ºC min and the temperature ranges were be-
tween 20–1000ºC using platinum crucibles. Highly
sintered α-Al O was used as a reference.
data, magnetic measurements, thermal analyses and
elemental analyses (Tables 1–3).
2
3
The ligand was prepared in a good yield. How-
ever, the complexes of the ligand were prepared in
lower yields. The complexes are paramagnetic with ex-
perimental magnetic moments of 9.63, 6.32 and 4.21
BM for Co(II), Ni(II) and Cu(II) complexes (Table 1),
respectively. These magnetic moments correspond to
six, four and three unpaired electrons that suitable for
Results and discussion
Ligand was prepared from the reaction of ω-chloro-
isonitrosoacetophenone [19] with the 1,4-phenylene-
diamine in the presence of NaHCO . Metal complexes
3
Scheme 1 Synthesis route of the ligand
Table 1 Magnetic measurements, physical properties and elemental analyses of the ligand and complexes
Calculated (found)/%
Molecular
Color
Compound
μeff*/BM
–1
D.p.**/°C
mass/g mol
yield/%
C
H
N
LH
4
yellow
80
65.67
4.51
13.92
–
402.41
175
112
120
109
C
22
H
18
N
4
O
4
(65.74)
(4.83)
(13.72)
[
Co
Co
3
3
(LH)
2
]·H
2
O
black
26
53.19
3.25
11.28
9
6
4
.63
.32
.21
993.59
1010.28
1025.44
[
(C44
H
30
N
8
O
8
)]·H
2
O
(53.46)
(3.05)
(11.48)
[
Ni
Ni
3
(LH)
2
]·2H
2
O
black
20
52.28
3.39
11.08
[
3
(C44
H
30
N
8
O
8
)]·2H
2
O
(52.66)
(3.37)
(10.91)
[
Cu
Cu
3
3
(LH)
2
]·2H
2
O
black
23
51.54
3.34
10.93
[
(C44
H
30
N
8
O
8
)]·2H
2
O
(51.86)
(2.98)
(11.25)
*
The magnetic moments of the complexes; **Decomposition points of the compounds
296
J. Therm. Anal. Cal., 85, 2006

Co(II), Ni(II) AND Cu(II) COMPLEXES OF 1,4-DI-(1-HYDROXYIMINO-2-PHENYL-2-OXO-ETHYLAMINO)BENZENE
Table 2 Thermal analyses data of the complexes in static air atmosphere
Total mass
Residue/%
loss/%
Mass loss/%
Removal
group
Complex
Stage
Trange /°C DTAmax /°C
found (calcd.)
found (calcd.)
1
2
3
4
44–120
102
–
3.2 (3.6)
11.6
2
2 mol H O
120–262
262–316
316–417
C
44
C
44
C
44
H
34
H
34
H
34
N
8
N
8
N
8
O
7
O
7
O
7
NiO
[Ni
3
(C44
H
30
N
8
O
8
)]·2H
2
O
79.8 (77.9)
295
11.8
20.2 (22.1)
395–411
53.1
1
2
3
4
40–109
109–225
225–303
303–384
101
184
–
3.6 (3.5)
13.3
2
2 mol H O
C
44
C
44
C
44
H
34
H
34
H
34
N
8
N
8
N
8
O
7
O
7
O
7
CuO
[
Cu
Co
3
(C44
(C44
H
30
N
8
O
8
)]·2H
2
O
74.9 (76.7)
78.6 (77.4)
11.3
25.1 (23.3)
351
46.7
1
2
3
45–112
112–255
255–420
105
207
2.2
15.4
60.9
2
1 mol H O
CoO
[
3
H
30
N
8
O
8
)]·H
2
O
C H N O
32 8
4
4
6
2
1.4 (22.6)
390–420
C
44
H
32
N
8
O
6
–
Table 3 IR spectra of the ligand and complexes in KBr pellets (cm )
1
C=Ocoord.
+
Compounds
LH
O–Hwater
N–H O–H C=Onon–coord.
C=N
C–N– N–O M–O
M–N
C=Nnon–coord.
4
–
3348 3234
1664
1670
1670
1668
–
1637
1618
1618
1619
1311
1336
1344
1363
962
941
939
937
–
–
[
[
[
Co
3
(LH)
2
]·H
2
O
3670–3350 3332
3670–3345 3340
3670–3360 3332
–
–
–
1653
1651
1658
523
516
524
339–316
362–327
339–318
Ni
3
(LH)
2
]·2H
2
O
3 2 2
Cu (LH) ]·2H O
tetrahedral geometry of metal environments, for
Co(II), Ni(II) and Cu(II) complexes, respectively.
nated waters and these are hydrated waters [21–23].
According to the TG and DTA curves, the dehydra-
tion process takes place in a single step which corre-
sponds exactly to loss of the crystal waters and the
Co(II) and Ni(II) complexes decompose in a similar
manner. The dehydration temperature of the com-
plexes lies in the range of 40–120ºC. On the basis of
1
H-NMR spectra of the ligand
1
In the H-NMR spectra of the ligand a singlet peak for
the OH protons of oxime group is observed at
1
1.06 ppm (2 H). The N–H protons adjacent to the
oxime groups in the ligand resonate at 8.44 ppm
2 H). The aromatic C–H protons resonate at
.94–6.51 ppm (14 H). The O–H and N–H peaks of
(
7
the ligand disappeared with the addition of deuterium
oxide to the solutions. These results are in good
agreement with those of known oximes [4, 14, 20].
Thermal analyses of the complexes
Both the elemental (Table 1) and thermal analyses
data (Table 2) of the complexes coincide with each
other and metal-ligand ratios were found to be 3:2 for
all complexes. Based on the elemental and thermal
analyses data, general structures for all complexes
found as [M (LH) ]·XH O. The thermal analyses
3 2 2
curves (TG and DTA) of the complexes are shown in
Figs 3–5 and the mass losses are summarized in
Table 2. The TG and DTA data and IR spectra show
that the first stages in the decomposition process of all
complexes are related to dehydration. For all com-
plexes, water is removed up to 120°C. This is indi-
cated that the waters in the complexes are non-coordi-
Fig. 3 Thermal analyses curves of the [Ni (LH) ]·2H O complex
3 2 2
J. Therm. Anal. Cal., 85, 2006
297

TAŸ, BATI
companied with the pyrolysis of the ligand (at 420 and
11ºC for the Co(II) and Ni(II) complex, respectively).
Total loss of masses were found to be 78.6%
calc.=77.4%), 79.8% (calc.=77.9%), 74.9%
calc.=76.7%) for Co(II), Ni(II) and Cu(II) complexes,
respectively. The results in calculated and found total
mass losses coincide with each other and are suitable
for the proposed general structure, [M (LH) ]·XH O.
The final decomposition products, namely MO
M=Ni(II), Cu(II) and Co(II)] were identified by IR
4
(
(
3
2
2
[
spectroscopy with corresponding spectra obtained un-
der the same conditions as the pure oxides.
IR spectra of the ligand and complexes
In the IR spectra of the ligand, bands at 3348, 3234,
–
664, 1637, 1367 and 962 cm belong to N–H, O–H,
1
1
C=O, C=N, –C–N– and N–O vibrations, respectively.
These values are in accord with those of previously
reported substituted oximes [5, 7, 14, 20]. IR spectra
of ligand and complexes were summarized in Table 3.
Based on the elemental and thermal analyses data
3 2 2
Fig. 4 Thermal analyses curves of the [Cu (LH) ]·2H O complex
2+
found for three moles M ions and two moles ligand,
the ligand must have –3 negative charge. For this, two
protons of the oxime groups and one proton of the
C–N–H groups should be separated upon complex for-
mation as expected. The IR results support the separated
oxime protons. A broad band for C–N– vibrations,
shifted to higher frequencies than the free ligand, indi-
cated that some of the N–H protons were deprotonated
upon complex formation and bonded to metals.
The complexes showed a broad band due to hy-
–1
drated water between 3345–3670 cm . In the IR spectra
of the complexes, the peaks at 3332–3340, 1670–1668,
–1
1658–1651, 1619–1618, 1363–1336, 941–937 cm are
attributed to N–H, non-coordinated C=O, both coordi-
nated C=O and non-coordinated C=N, coordinated
C=N, C–N– and N–O vibrations, respectively. In the
complexes, shifting to lower frequencies for N–H vibra-
tions showed nitrogen of the N–H group coordinated to
the metals. This is supported by the shifting to higher
–1
frequencies than the free ligand (at 1311 cm ), for
–1
C–N– as the broad band (1336, 1344, 1363 cm for
Co(II), Ni(II) and Cu(II) complexes, respectively) [24].
These bands belong to both neutrally coordinated
C–N–H and ionically bonded C–N– vibrations and oth-
erwise the peak for C–N– should be sharp. Shifting to
higher frequencies than the free ligand for C–N vibra-
tions indicates the nitrogen atoms of the amide groups
bonded to the metal ions [14, 24]. The O–H vibrations
of the oxime groups disappeared in the IR spectra of the
complexes indicated that the oxime protons were sepa-
rated upon complex formation and bonded to the metals.
This result is supported by shifting N–O vibrations to
3 2 2
Fig. 5 Thermal analyses curves of the [Co (LH) ]·H O complex
the DTAmax, the thermal stability of the hydrated com-
plexes follows the order: Co(II)(105ºC)>
Ni(II)(102ºC)≅ Cu(II) (101ºC).
After dehydratation, the pyrolysis of the ligand
takes place in the anhydrous complexes in three steps.
But decomposition stages are not differentiated from
each other exactly. Maximum exothermic decomposi-
tion of the ligand occurred at 390, 395 and 351ºC for
the Co(II), Ni(II) and Cu(II) complexes, respectively.
For Co(II) and Ni(II) complexes, at the last decomposi-
tion stage, another exothermic decomposition is ac-
–1
lower frequencies (941, 939, 937 cm for Co(II), Ni(II)
and Cu(II) complexes, respectively) than the free ligand
298
J. Therm. Anal. Cal., 85, 2006

Co(II), Ni(II) AND Cu(II) COMPLEXES OF 1,4-DI-(1-HYDROXYIMINO-2-PHENYL-2-OXO-ETHYLAMINO)BENZENE
–
1
(
at 962 cm ) [14, 20]. Based on IR spectra results, one
4 M. V. Barybin, P. L. Diaconescu and C. C. Cummins,
Inorg. Chem., 40 (2001) 2892.
of the carbonyl groups (C=O) of the ligands remained
non-coordinated to the metals as C=O stretching vibra-
tions shifted to higher frequencies and the other one co-
ordinated to the metal ions as C=O stretching vibrations
shifted to lower frequencies [5, 7, 14]. For C=N vibra-
tions, the spectra of the complexes had one peak at
5
S. Sevagapandian, G. Rajagopal, K. Nehru and
P. Athappan, Transition Metal Chem., 25 (2000) 388.
R. M. Srivastava, I. M. Brinn, J. O. Machura-Herrera,
H. B. Faria, G. B. Carpenter, D. Andrade, C. G. Venkatesh
and L. P. F. Morais, J. Mol. Struct., 406 (1997) 159.
C. Natarajan and A. N. Hussain, Ind. J. Chem.,
20A (1981) 307.
6
7
–1
1
619–1618 cm indicated the oxime nitrogen coordi-
nated to the metals [5, 7, 14, 20]. But, one of the oxime
nitrogens should coordinate to the metals because of
steric hindrance [24]. So, there must be two peaks for
C=N vibrations, the one at the higher frequency indicat-
ing non-coordinated and the other one at the lower fre-
quency indicating coordinated position. However, the
peaks indicating coordinated C=N were seen in the IR
spectra whereas the peaks of non-coordinated oxime ni-
trogen were not discerned. The peaks may be sup-
pressed by the C=O peaks that indicating coordinating
C=O group. In the IR spectra of the complexes, metal-
oxygen and metal-nitrogen bonds were identified be-
8 S. Y. Kim, M. Harada, H. Tomiyasu, Y. Ikeda and
Y. Y. Park, Prog. Nuclear Energy, 37 (2000) 399.
U. B. Talwar and B. C. Haldar, Anal. Chim. Acta,
1 (1970) 53.
0 P. S. More and A. D. Sawant, J. Ind. Chem. Soc.,
3 (1996) 377.
9
5
1
1
1
7
1 T. Suzuki, K. Saito, T. Sugo, H. Ogura and K. Oguma,
Anal. Sci., 16 (2000) 429.
2 P. S. Reddy and K. H. Reddy, Polyhedron, 19 (2000) 1687.
13 V. N. Yarovenko, S. A. Kosarev, I. V. Zavarzin and
M. M. Krayushkin, Electronic Conference on Heterocyclic
Chemistry, 29 June–24 July 1998 poster no. 55.
14 F. Karipçin, H. . Uçan and . Karataê, Transition Met. Chem.,
–1
27 (2002) 813.
tween 524–516 and 362–316 cm , respectively
14, 20, 25].
Consequently, the ligand coordinated to the
1
1
1
5 T. Hökelek, M. Taê and H. BatÏ, Cryst. Res. Technol.,
[
39 (2004) 363.
6 O. Büyükgüngör, T. Hökelek, M. Taê and H. BatÏ,
Acta Cryst. E59 (2003) 883.
metal ions through nitrogen of the C–N–H group, one
of the carbonyl group, nitrogen and oxygen atoms of
the oxime groups and, nitrogen atoms of deprotonated
amide groups (Fig. 2) [1–5, 7, 14].
7 U. SarÏ, H. BatÏ, K. Güven, M. Taê and . Aksoy,
Analytical Sciences X-Ray Structure Analyses Online,
19 (2003) x61.
1
1
8 S. Soylu, M. Taê, Ö. Andaç, H. BatÏ, N. ÇalÏêkan and
O. Büyükgüngör, Acta Cryst., E59 (2003) o1532.
9 Z. Hamersak, B. Peric, B. Kojic-Prodic, L. Cotarca,
P. Delodu and V. Sunjic, Helvetica Chimica Acta,
UV-Vis spectra
The ligand showed an absorption band for π→π* at
–
1
–1
2
56 nm (ε=19044 M cm ) and for n→π* at 327 nm
8
2 (1999) 1289.
20 A. ZülfikaroÈlu, M. Taê, H. BatÏ and B. BatÏ,
Synth. React. Inorg. Met.-Org. Chem., 33 (2003) 625.
–1 –1
(
ε=1749 M cm ) in the UV-Vis spectra. For com-
plexes, d→d transitions were not observed; because
of the peaks were under the charge transfer bands.
The charge transfer bands were at 476 nm (ε=5466),
2
2
2
2
2
1 N. H. Patel, H. M. Parekh and M. N. Patel,
Transition Met. Chem., 30 (2005) 13.
2 S. A. Abdel-Latif, O. M. El-Roudi and M. G. K. Mohamed,
J. Therm. Anal. Cal., 73 (2003) 939.
4
00 (ε=4009), 460 (ε=16293) for cobalt, nickel and
copper complexes, respectively.
3 S. B. Jagtap, R. C. Chikate, O. S. Yemul, R. S. Ghadage
and B. A. Kulkarni, J. Therm. Anal. Cal., 78 (2004) 251.
4 R. C. Maurya and S. Rajput, Synth. React. Inorg.
Met.-Org. Chem., 33 (2003) 1877.
Acknowledgements
5 A. Hudák and A. Koëturiak, J. Therm. Anal. Cal.,
The authors give deep thanks to Research Funding of Ondokuz
58 (1999) 579.
MayÏs University for financial supports (Project No: F-249).
Received: July 18, 2005
Accepted: November 16, 2005
OnlineFirst: March 20, 2006
References
1
2
A. Chakravorty, Coordination Chem. Rev., 13 (1974) 1.
M. E. Keeney and K. Osseo-Asare, Coordination Chem. Rev.,
9 (1984) 141.
V. Y. Kukushkin and A. J. L. Pomberio, Coordination
Chem. Rev., 181 (1999) 147.
DOI: 10.1007/s10973-005-7112-y
5
3
J. Therm. Anal. Cal., 85, 2006
299