Synthesis, characterization, and catalytic performance in oxidation of styrene and α-methyl styrene of a nickel(II) complex derived from a Schiff base ligand

Article abstract of DOI:10.1002/zaac.201100040

A tetrahedrally-distorted square-planar nickel(II) complex of tetradentate Schiff base ligand derived from 2-hydroxypropiophenone and 2,2′- dimethylpropandiamine [bis(2-hydroxypropiophenone)2,2′- dimethylpropylenediimine] (H₂L) was prepared and used as catalyst for oxidation of styrene and α-methyl styrene with tert-butylhydroperoxide (TBHP). Oxidation of styrene with TBHP gave benzaldehyde and styrene oxide, but in the case of α-methylstyrene a mixture of α-methylstyrene oxide and acetophenone was obtained. The structure of nickel(II) complex (NiL) was determined by X-ray crystallography. Crystal data for NiL at -173 °C: orthorhombic, space group P2₁2₁2₁, a = 907.7(1), b = 1289.4(1), c = 1752.4(1) pm, Z = 4, R₁ = 0.0454. Copyright

Full text of DOI:10.1002/zaac.201100040

ARTICLE
DOI: 10.1002/zaac.201100040
Synthesis, Characterization, and Catalytic Performance in Oxidation of
Styrene and α-Methyl Styrene of a Nickel(II) Complex Derived from a Schiff
Base Ligand
Felora Heshmatpour,*[a] Saeed Rayati,*[a] Mona Afghan Hajiabbas,[a] and
Bernhard Neumüller[b]
Keywords: Catalyst; Crystal structure; Nickel; Oxidation; Schiff bases
Abstract. A tetrahedrally-distorted square-planar nickel(II) complex dehyde and styrene oxide, but in the case of α-methylstyrene a mixture
of tetradentate Schiff base ligand derived from 2-hydroxypropiophen- of α-methylstyrene oxide and acetophenone was obtained. The struc-
one and 2,2'-dimethylpropandiamine [bis(2-hydroxypropiophen- ture of nickel(II) complex (NiL) was determined by X-ray crystallogra-
one)2,2'-dimethylpropylenediimine] (H2L) was prepared and used as phy. Crystal data for NiL at –173 °C: orthorhombic, space group
catalyst for oxidation of styrene and α-methyl styrene with tert-butyl- P212121, a = 907.7(1), b = 1289.4(1), c = 1752.4(1) pm, Z = 4, R1 =
hydroperoxide (TBHP). Oxidation of styrene with TBHP gave benzal- 0.0454.
which they are synthesized, the outstanding versatility they
1. Introduction
have, and a great deal of complexing ability they show[39]
.
Schiff base ligands and their metal complexes are easily syn-
thesized. Therefore, transition metal complexes with Schiff
base ligands have been extensively used as catalyst in various
reactions such as oxidation,[1–3] ring opening reaction of
Moreover, Schiff base ligands may be tuned both sterically and
electronically by the variation of respective amine and alde-
hyde or ketone ligand precursors.[40]
In this paper, the synthesis, characterization, and molecular
structure of a NiII complex of a Schiff base ligand derived from
2,2'-dimethylpropylenediamine and 2-hydroxypropiophenone
are reported and also catalytic performance of the complex for
oxidation of styrene and α-methyl styrene with tert-butylhy-
droperoxide (TBHP) are investigated.
epoxides,[4,5] aldol condensation[6–8] and epoxidation.[9–19]
A
wide variety of transition metals such as chromium(III),[20]
manganese(II),[21,22] oxovanadyl(IV),[23,24] cobalt(II),[25,26]
nickel(II),[27] and copper(II)[28] were used in preparation of
Schiff base complexes and tested for their activity in the oxida-
tion reactions.
The study of nickel compounds attracts considerable atten-
tion in different aspects of chemistry, because these com-
pounds are present in active sites of urease and are widely used
in the design and construction of novel magnetic
materials.[29–31] Also a large number of NiII complexes are ap-
plied as models in biological process for understanding the
structure of biomolecules.[32,33]
Great attention has recently been paid to 2-hydroxy Schiff
base ligands owing to their different crystallographic, struc-
tural, and magnetic characteristics.[34–38] Their enduring appeal
and increasing popularity can be explained by the ease with
2. Results and Discussion
2.1. Synthesis and Spectroscopic Characterization
The tetradentate Schiff base ligand (H2L) was synthesized
by 1:2 condensation reaction of 2,2'-dimethylpropylenediam-
ine and 2-hydroxypropiophenone in ethanol under reflux in
good yield according to Scheme 1. The analytical data of H2L
is in agreement with the formulation of this compound.
* Dr. F. Heshmatpour
Fax: +98-21-22853650
E-Mail: heshmatpour@kntu.ac.ir
* Dr. S. Rayati
E-Mail: rayati@kntu.ac.ir
[a] Department of Chemistry
K. N. Toosi University of Technology
P.O. Box 16315–1618
Tehran 15418, Iran
[b] Fachbereich Chemie
Universität Marburg
Hans-Meerwein-Straße
35032 Marburg, Germany
Scheme 1. Preparation of the Schiff base ligand.
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Z. Anorg. Allg. Chem. 2011, 637, 1224–1228

Styrene and α-Methyl Styrene of a Nickel(II) Schiff Base Complex
The nickel(II) complex with this ligand was prepared by 2.2. Crystal Structure Analysis of NiL
treatment of H2L with Ni(OAc)2·4H2O in molar ratio 1:1 in
Deep green crystals of NiL, suitable for X-ray diffraction
ethanol according to Scheme 2.
studies, were obtained. The compound crystallizes in the or-
thorhombic space group P212121 with four molecules in the
unit cell. An ORTEP view of NiL is shown in Figure 1. L2–
acts as a tetradentate ligand. The most interesting phenomenon
observed is the fact that both of the phenol groups of the ligand
are coordinated as phenolate, which neutralizes the 2+ charge
of NiII. Selected bond lengths and bond angles for the complex
are summarized in Table 1.
Scheme 2. Preparation of the nickel(II) complex.
1
The complex, which was identified by IR, UV/Vis, and H
NMR spectroscopy and elemental analysis, are remarkably sta-
ble to air, water, and heat.
The infrared spectra for the ligand (H2L) and its complex
(NiL) exhibit the characteristic vibrational frequencies. The
band corresponding to the azomethine group of the free ligand
is observed at 1617 cm–1. Another broad band around
1570 cm–1 in H2L is related to aromatic (C=C) vibration. The
lowering of the positions of the bands indicates their coordina-
tion to the metal atom.[41] The IR spectra of complex has a
very strong and broad band corresponding to ν(C=N) centered
at 1606 cm–1. The bands are broad probably due to their over-
lapping with the aromatic ring-carbon stretching. The C–O
stretching vibration in free ligand is observed at 1220 cm–1.
Figure 1. Molecular structure of NiL (thermal ellipsoids are at the
40 % probability level).
Table 1. Selected bond lengths /pm and bond angles /° for NiL.
Ni(1)–O(1)
189.2(2)
195.7(3)
130.9(4)
130.5(4)
146.6(4)
143.2(5)
147.2(5)
151.3(5)
188.5(2)
196.7(3)
130.7(4)
129.8(4)
147.8(4)
142.4(5)
147.2(5)
151.5(5)
N(1)–Ni(1)–N(2)
O(1)–Ni(1)–N(1)
C(6)–O(1)–Ni(1)
C(7)–N(1)–Ni(1)
C(6)–C(1)–C(7)
N(1)–C(7)–C(1)
C(7)–N(1)–C(10)
O(2)–Ni(1)–N(2)
O(2)–Ni(1)–O(1)
C(17)–O(2)–Ni(1)
C(15)–N(2)–Ni(1)
92.8(1)
This frequency shifts in the complex towards lower or higher Ni(1)–N(1)
92.6(1)
O(1)–C(6)
125.3(2)
128.9(2)
123.1(3)
120.1(3)
123.8(3)
93.6(1)
92.7(1)
126.4(2)
128.4(2)
values as a result of coordination of the oxygen to the metal
N(1)–C(7)
ion.[42] The ν(C–O) band of H2L at 1220 cm–1 shifts to
N(1)–C(10)
1206 cm–1 in NiL.
C(1)–C(6)
The electronic spectrum of the Schiff base ligand recorded
in CHCl3 exhibits two bands, a relative intense band at 250 nm
(ε = 18780 m–1·cm–1) and a band of low intensity at 330 nm
(ε = 7740 m–1·cm–1). Based on their extinction coefficients
these are assigned as due to π→π* and n→π* transitions,
respectively.[43,44]
C(1)–C(7)
C(7)–C(8)
Ni(1)–O(2)
Ni(1)–N(2)
O(2)–C(17)
N(2)–C(15)
N(2)–C(12)
C(16)–C(17)
C(15)–C(16)
C(15)–C(22)
C(17)–C(16)–C(15) 123.6(3)
N(2)–C(15)–C(16)
C(15)–N(2)–C(12)
O(1)–Ni(1)–N(2)
O(2)–Ni(1)–N(1)
121.2(3)
121.8(3)
154.1(1)
153.7(1)
The formation of H2L was followed by NMR spectroscopy
until the complete disappearance of the amine proton signals
1
at 1.10 ppm in the H NMR spectrum, and the ketone C=O
1
signal at 207.11 ppm in the 13C NMR spectrum. The H NMR
spectrum of the tetradentate Schiff base ligand of N2O2 donor
The coordination sphere around NiII is a tetrahedrally dis-
sets shows the signals of two phenol groups at 12.34 ppm. The torted square-planar arrangement because of the twist confor-
spectrum also shows signals of the aromatic protons in the mation of the N1–C10–C11–C12–N2 sequence. In contrast,
range 6.73–7.50 ppm. The signals of the methylene protons both Ni–N–C–C–C–O rings are almost planar. X-ray structure
appear at 2.74–2.81 ppm and those of the methyl protons at analysis of NiL shows that the nickel atom is coordinated by
1.15–1.23 ppm.
all four atoms of the N2O2 donor set. The distortion of the
1
The comparison of the H NMR spectrum of the free ligand central NiN2O2 unit can be described by the angle of 36° be-
with its nickel complex shows disappearance of the OH pro- tween the two planes Ni1/N1/O1 and Ni1/O2/N2. The bond
tons present in the free ligand, which is in agreement with the lengths and angles are in agreement with the values for tetraco-
bis-deprotonation of the ligand. The signals of the methylene ordinate low-spin divalent nickel complexes.
and methyl protons of NiL appear at 3.56–2.07 ppm and 1.23–
The Ni–O(1) (189.2(2) pm), Ni–O(2) (188.5(2) pm), Ni–
0.66 ppm, respectively. The signals of the aromatic protons in N(1) (195.7(3) pm), and Ni–N(2) (196.7(3) pm) distances are
NiL lie in the range of 7.76–6.52 ppm.
similar to the corresponding Ni–O (182 pm) and Ni–N(imine)
Z. Anorg. Allg. Chem. 2011, 1224–1228
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F. Heshmatpour, S. Rayati et al.
ARTICLE
(189 pm) distances in [Ni(Me-sal)dpt]Cl,[45] and Ni–O
(184 pm) and Ni–N (187 pm) in NiDAO.[46] As a result of the
molecular packing in the crystal structure of NiL the complex
molecules are packed in columns along [010].
4. Experimental Section
4.1. General Information
Solvents (ethanol and acetonitrile) were dried and distilled by standard
methods before use.[51] 2,2'-Dimethylpropylenediamine (Merck,
98 %), 2-hydroxypropiophenone (Across, 97 %) were used as re-
ceived.
2.3. Catalytic Activity Studies
Since studies of the non-enzymatic oxygenation reactions
help us to the understanding of the oxygenase-catalyzed reac-
tions, and on the other hand oxidation of organic substrates in
the presence of metal complexes have immense importance
from synthetic point of view, we have investigated the catalytic
potential of the NiL for the oxidation of styrene and α-methyl
styrene.
The oxidation of styrene and α-methyl styrene, catalyzed by
NiL was carried out using tert-butylhydroperoxide as an oxi-
dant and the results of oxidation reactions are shown in Ta-
ble 2. Styrene catalyzed by tert-butylhydroperoxide in the
presence of catalytic amounts of NiL gives two reaction pro-
ducts, styrene oxide and benzaldehyde. Styrene oxide was ob-
tained only in poor yield, whereas the yield of benzaldehyde
4.2. Instrumentation
Infrared spectra were recorded as KBr pellets with a Unicam Mattson
1000 FT-IR. Elemental analysis (C, H, N) were performed with a Her-
aeus Elemental Analyzer CHN-O-Rapid (Elemental-Analyze System
KBr pellets, GmbH, Germany). 1H and 13C NMR spectra were ob-
tained in CDCl3 solutions with a Bruker FT-NMR 250 (250 MHz)
spectrometer. The residual CHCl3 in conventional 99.8 at.-%. CDCl3
gives a signal at 7.26 ppm, which was used for calibration of the chem-
ical shift scale, and 13C{1H} NMR chemical shifts are reported relative
to CDCl3 (77.0 ppm). A digital melting point measuring device (Elec-
trotermal 9100) was used. A double beam spectrophotometer (Shi-
madzu, UV-240) was used for the UV-Vis absorption determination.
is higher. In the case of α-methyl styrene, epoxide and aceto- 4.3 Preparations
phenone were obtained as products, whereas acetophenone is
H2L: A solution of 2,2'-dimethylpropylenediamine (0.102 g, 1 mmol)
the major product. The higher reactivity observed in the case
of α-methyl styrene in comparison with styrene seems to be
due to the electron donation effect of the methyl group to the
double bond. The double bond may be considered as a nucleo-
phile in the oxidation reaction. According to the results shown
in Table 2, the obtained benzaldehyde and acetophenone pro-
ducts are due to the over oxidation of styrene oxide and α-
methyl styrene respectively.[47] Additionally, higher conversion
and turnover numbers were achieved in this catalytic system
in comparison with other reported NiII Schiff base
complexes.[48–50]
in ethanol (30 mL) was treated with 2-hydroxypropiophenone
(0.300 g, 2 mmol). The bright yellow solution was stirred and heated
to reflux for 1 h. A yellow precipitate was obtained that was filtered
off, washed with diethyl ether (2 × 5 mL). The crude was dissolved
in dichloromethane (10 mL) and kept at room temperature to give
bright yellow crystals of H2L after a few days. Yield 0.326 g, 89 %.
1H NMR (CDCl3): δ = 12.34 (s, 2 H, OH), 7.50–6.73 (m, 8 H, Ar–
3
H), 3.56 (s, 4 H, NCH2), 2.81–2.74 [q, J(H,H) = 7.7 Hz, 4 H, N =
3
CCH2], 1.23 (s, 6 H, CH3), 1.20–1.15 [t, J(H,H) = 7.7 Hz, 6 H, N =
CCH CH ]. IR (KBr): ν = ν(O–H) 3419 m, ν(C=N) 1617 s, ν(C=C)
˜
2
3
1570 m, ν(C–O) 1220 m cm–1. C23H30N2O2 (366.49): calcd. C 73.37,
H 8.25, N 7.67 %; found C 73.45, H 8.31, N 7.56 %. 13C{1H} NMR:
δ
= 55.66 (C=NCH2), 35.72 [C=NCH2C(CH3)2], 24.61 [C=
NCH2C(CH3)2], 21.00 (N=CCH2CH3), 11.61 (N=CCH2CH3), 116.92–
Table 2. Oxidation of styrene and α-methyl styrene with TBHP cata-
lyzed by nickel complex in CH3CN.
165.09 (aromatic C), 177.29 (C=N).
b)
Alkene
Styrene
Con.a) /% Yield /%
TONc)
NiL: A solution of H2L (0.366 g, 1 mmol) in ethanol (20 mL) was
added to a suspension of Ni(OAc)2·4H2O (0.248 g, 1 mmol). The reac-
tion mixture was heated to reflux for 1 h. The colored solution was
concentrated to yield colored powders. The product was washed with
warm ethanol. The clear filtrate was kept at 25 °C to give the green
crystals of the nickel complex. Yield 0.402 g, 95 %. 1H NMR
(CDCl3): δ = 7.76–6.52 (m, 8 H, Ar–H), 3.56 (s, NCH2), 3.03–2.07
(q, 4 H, N=CCH2), 1.23 (s, 6 H, CH3), 1.02–0.66 (t, 6 H, NCCH2CH3).
58
9 (epoxy) 49 (benzaldehyde) 181
13 (epoxy) 84 (acetophenone) 303
α-Methyl styrene 97
a) GC yields are based on starting alkenes. b) All the reactions were
run at least in triplicate, and the data represent an average of these
reactions. c) Turnover number (TON) is the ratio of the number of
moles of products to number of moles of catalyst.
]. IR (KBr): ν = ν(C=N) 1606 s, ν(C=C) 1581 s, ν(C–O) 1206 m cm–1.
˜
UV/Vis (CHCl3): λmax
= 256 (ε = =
9600 m–1·cm–1), 337 (ε
2690 m–1·cm–1) nm. C23H28N2NiO2 (423.18): calcd. C 65.27, H 6.66,
N 6.61, Ni 13.87 %; found C 65.43, H 6.51, N 6.69, Ni 13.72 %.
13C{1H} NMR δ = 55.83 (C=NCH2), 31.04 [C=NCH2C(CH3)2], 24.10
[C=NCH2C(CH3)2], 20.42 (N=CCH2CH3), 11.07 (N=CCH2CH3),
116.35–164.03 (aromatic C), 176.73 (C=N).
3. Conclusions
N2O2 tetradentate Schiff base ligand (H2L) and its NiII com-
plex were prepared and characterized. Crystal structure of the
complex (NiL) was determined. In the crystal structure, the
nickel atom has a tetrahedrally distorted square-planar arrange-
ment. This complex has potential activity for oxidation of sty-
rene and α-methyl styrene. The conversion of styrene is 58 %
and for α-methyl styrene 97 %.
4.4. General Oxidation Procedure
The catalyst (NiL) (0.032 mmol) was dissolved in acetonitrile (10 mL)
in a 50 mL round-bottomed flask equipped with a condenser. After-
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© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Z. Anorg. Allg. Chem. 2011, 1224–1228

Styrene and α-Methyl Styrene of a Nickel(II) Schiff Base Complex
wards, the alkene (styrene or α-methyl styrene) (10 mmol) and TBHP
(30 mmol) were added, respectively. The mixture was heated to reflux
for 6 h. Samples were taken at periodic time intervals and analyzed by
gas chromatography. The oxidation products were identified by com-
parison with authentic samples (retention times in GC).
Acknowledgement
This work was supported by the K.N. Toosi University of Technology.
References
[1] F. Hueso-Urena, N. A. Illan-Cabeza, M. N. Moreno-Carretero,
J. M. Martinez-Martos, M. J. Ramirez-Exposito, J. Inorg. Bio-
chem. 2003, 94, 326–334.
4.5. X-ray Crystallography
The selected crystals of NiL were covered with perfluorinated oil and
mounted on the top of a glass capillary in a flow of cold gaseous
nitrogen. The orientation matrix and the unit cell dimensions were
determined from 4000 reflections [Stoe IPDS 2T graphite-monochro-
[2] F. Farzaneh, M. Majidian, M. Ghandi, J. Mol. Catal. A 1999, 148,
227–233.
[3] G. T. Musie, M. Wei, B. Subramaniam, D. H. Busch, Inorg.
Chem. 2001, 40, 3336–3441.
mated Mo-Kα radiation (λ = 71.073 pm); see also Table 3]. The intensi- [4] M. Tokunaga, J. F. Larrow, F. Kakiuchi, E. N. Jacobson, Science
1997, 277, 936–938.
ties were corrected for Lorentz and polarizations effects. In addition,
absorption corrections were applied for NiL (numerical). The structure
was solved by direct methods using SIR-92 and was refined against
F2 by full-matrix least-squares using the program SHELXL-97. The
hydrogen atoms were calculated in ideal positions and were refined
[5] M. D. Angelino, P. E. Laibinis, J. Polym. Sci. A 1999, 37, 3888–
3898.
[6] C. Chapuis, D. Jacoby, Appl. Catal. A 2001, 221, 93–117.
[7] L. Liu, M. Rozenman, R. Breslow, Bioorg. Med. Chem. 2002, 10,
3973–3979.
with
a common displacement parameter. Programs used were
[8] H. Hayashi, J. Biochem. 1995, 118, 463–473.
[9] J. F. Kinneary, T. R. Wagler, C. J. Burrows, Tetrahedron Lett.
1988, 29, 877–880.
SHELXL-97,[52] SIR-92,[53] SHELXTL-Plus,[54] and PLATON.[55]
[10] H. Yoon, T. R. Wagler, K. J. O’Connor, C. J. Burrows, J. Am.
Chem. Soc. 1990, 112, 4568–4570.
Table 3. Crystal data and structure refinement for NiL.
NiL
[11] J. F. Kinneary, J. S. Albert, C. J. Burrows, J. Am. Chem. Soc.
1988, 110, 6124–6129.
Empirical formula
Formula mass
Crystal size /mm
Crystal system
Space group
a /pm
C23H28N2NiO2
423.18
[12] H. Yoon, C. J. Burrows, J. Am. Chem. Soc. 1988, 110, 4087–
4089.
0.18 × 0.12 × 0.04
orthorhombic
P212121
907.7(1)
1289.4(1)
1752.4(1)
90
[13] V. Ayala, A. Corma, M. Iglesias, J. A. Rincón, F. Sánchez, J.
Catal. 2004, 224, 170–177.
[14] M. R. Maurya, S. J. J. Titinchi, S. Chand, J. Mol. Catal. A 2003,
201, 119–130.
b/pm
[15] D. Chatterjee, S. Mukherjee, A. Mitra, J. Mol. Catal. A 2000,
154, 5–8.
c /pm
α /°
[16] R. I. Kureshy, N. H. Khan, S. H. R. Abdi, S. T. Patel, P. Iyer, E.
Suresh, P. Dastidar, J. Mol. Catal. A 2000, 160, 217–227.
[17] D. Chatterjee, A. Mitra, J. Mol. Catal. A 1999, 144, 363–367.
[18] R. Ferreira, H. García, B. D. Castro, C. Freire, Eur. J. Inorg.
Chem. 2005, 4272–4279.
β /°
90
90
γ /°
Volume /pm3 × 106
Z
2051.0(3)
4
D
calcd. /g· cm–3
1.37
[19] K. C. Gupta, A. K. Sutar, Coord. Chem. Rev. 2008, 252, 1420–
1450.
Absorp. correction
μ /cm–1 (Mo-Kα)
T /K
numerical
9.67
[20] X. G. Zhou, J. S. Huang, X. Q. Yu, Z. Y. Zhou, C. M. Che, J.
Chem. Soc. Dalton Trans. 2000, 1075–1080.
[21] A. Zsigmond, A. Horvath, F. Notheisz, J. Mol. Catal. A 2001,
171, 95–102.
100
56.74
2θmax /°
Index range
–12 ≤ h ≤ 10
–14 ≤ k ≤ 17
–23 ≤ l ≤ 19
8564
[22] D. E. D. Vos, P. P. Knops-Gerrits, D. L. Vanoppen, P. A. Jacobs,
Supramol. Chem. 1995, 6, 49–57.
Reflections collected
[23] S. Rayati, M. Koliaei, F. Ashouri, S. Mohebbi, A. Wojtczak, A.
Kozakiewicz, Appl. Catal. A 2008, 346, 65–71.
[24] S. Rayati, A. Wojtczak, A. Kozakiewicz, Inorg. Chim. Acta 2008,
361, 1530–1533.
Uniq. reflect.
4931
Rint
0.0669
Reflect. with Fo > 4σ(Fo)
4088
Parameters
258
[25] D. Hu, Y. Wi, X. Dang, Y. Fang, React. Funct. Polym. 2000, 48,
1–3.
Flack parameter
–0.02(2)
0.0454
R1
[26] A. Zsigmond, F. Notheisz, Z. Frater, J. E. Backvall, Stud. Surf.
Sci. Catal. 1997, 108, 453–459.
wR2 (all data)
0.1049a)
0.385
Max. residual electron density /
[27] R. I. Kureshy, N. H. Khan, S. H. R. Abdi, S. T. Patel, P. K. Iyer,
R. V. Jasra, J. Catal. 2002, 209, 99–104.
e·pm–3 × 10–6
a) w = 1/[σ2(Fo )+(0.0575P)2]; P = [max (Fo , 0)+2Fc ]/2.
2
2
2
[28] S. Rayati, S. Zakavi, M. Koliaei, A. Wojtczak, A. Kozakiewicz,
Inorg. Chem. Commun. 2010, 13, 203–207.
[29] P. A. Karplus, M. A. Pearson, R. P. Hausinger, Acc. Chem. Res.
1997, 30, 330–337.
The crystallographic data (excluding structure factors) for the structure
in this paper have been deposited with the Cambridge Crystallographic
Data Centre as supplementary publication number CCDC-806604
(NiL). Copies of the data can be obtained, free of charge, by applica-
tion to CCDC, 12 Union Road, Cambridge, CB2 1EZ, UK (Fax: +44-
1223-336033; E-Mail: data_request@ccdc.cam.ac.uk or via the inter-
net: http://www.ccdc.cam.ac.uk/products/csd/request.)
[30] H. L. Zhu, L. M. Zheng, J. Zhao, W. M. Bu, W. X. Tang, Transi-
tion Met. Chem. 1999, 24, 131–134.
[31] H. L. Zhu, Y. X. Tong, X. M. Chen, C. X. Ren, Transition Met.
Chem. 2001, 26, 528–531.
[32] J. E. Kovacic, Spectrochim. Acta 1987, 23, 183–186.
[33] R. Atkins, G. Brewer, E. Kokot, G. M. Mockler, E. Sinn, Inorg.
Chem. 1985, 24, 127–134.
Z. Anorg. Allg. Chem. 2011, 1224–1228
© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
www.zaac.wiley-vch.de
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F. Heshmatpour, S. Rayati et al.
ARTICLE
[34] M. Yildiz, Z. Kilic, T. Hokelek, J. Mol. Struct. 1998, 441, 1–10.
[35] Y. Sunatsuki, Y. Motoda, N. Matsumoto, Coord. Chem. Rev. 2002,
226, 199–209.
[47] T. Joseph, D. Srinivas, C. S. Gopinath, S. B. Halligudi, Catal.
Lett. 2002, 83, 209–214.
[48] M. R. Maurya, A. K. Chandrakar, S. Chand, J. Mol. Catal. A
2007, 274, 192–201.
[36] D. P. Kessissoglou, M. L. Kirk, M. S. Lah, X. Li, C. Rapto-
poulou, W. E. Hatfield, V. L. Pecoraro, Inorg. Chem. 1992, 31,
5424–5432.
[49] V. K. Bansal, P. P. Thankachan, R. Prasad, Appl. Catal. A 2010,
381, 8–17.
[50] V. Mirkhani, M. Moghadam, S. Tangestaninejad, I. Mohammad-
poor-Baltork, E. Shams, N. Rasouli, Appl. Catal. A 2008, 334,
106–111.
[37] T. Bassov, M. Sheves, Biochemistry 1986, 25, 5249–5258.
[38] L. A. Herrero, A. Terron, Polyhedron 1998, 17, 3825–3833.
[39] P. Mukherjee, C. Biswas, M. G. B. Drew, A. Ghosh, Polyhedron
2007, 26, 3121–3128.
[51] D. D. Perrin, W. L. F. Armarego, D. R. Perrin, in Purification of
Laboratory Chemicals, 2nd ed., Pergamon Press, Oxford, 1980.
[52] G. M. Sheldrick, SHELXL-97, Göttingen, Germany 1997.
[53] A. Altomare, G. Cascarano, C. Giacovazzo, A. Guagliardi, M. C.
Burla, G. Polidori, M. Camalli, SIR-92, Bari, Perugia, Rome,
1992.
[40] S. Rayati, N. Sadeghzadeh, H. R. Khavasi, Inorg. Chem. Com-
mun. 2007, 10, 1545–1548.
[41] P. Sousa, J. A. G. Vazquez, J. A. Masaquer, Transition Met.
Chem. 1984, 9, 318–321.
[42] K. Nakamoto, in Infrared and Raman Spectra of Inorganic and
Coordination Compounds, Wiley, New York, 1987.
[43] M. R. Maurya, A. Kumar, J. Mol. Catal. A 2006, 250, 190–198.
[44] M. R. Maurya, S. Khurana, C. Schulzke, D. Rehder, Eur. J. Inorg.
Chem. 2001, 779–788.
[54] G. M. Sheldrick, SHELXTL-Plus, Release 5.05/VMS for Siemens
R3 Crystallographic Research Systems, Siemens Analytical X-ray
Instruments Inc., Madison (WI), 1996.
[55] A. L. Spek, PLATON-98, Utrecht, 1998.
[45] M. Amirnasr, K. J. Schenk, S. Meghdadi, M. Morshedi, Polyhe-
dron 2006, 25, 671–677.
[46] J. Eilmes, M. Basato, G. Valle, Inorg. Chim. Acta 1999, 290, 14–
20.
Received: January 17, 2011
Published Online: May 12, 2011
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