Zinc(II) and Co(II) complexes based on bis(N-allylbenzimidazol-2-ylmethyl) aniline: Synthesis, crystal structures and antioxidative activity

Article abstract of DOI:10.3184/174751915X14210834541638

Bis(N-allylbenzimidazol-2-ylmethyl)aniline (L) and its complexes, [Zn(L)(Cl)2] and [Co(L)(Cl)2], have been synthesised and the structures of both complexes have been determined. [Zn(L)(Cl)2] can be described as distorted tetrahedron, while [Co(L)(Cl)2] ha

Full text of DOI:10.3184/174751915X14210834541638

76 RESEARCH PAPER
VOL. 39 FEBRUARY, 76–81
JOURNAL OF CHEMICAL RESEARCH 2015
Zinc(II) and Co(II) complexes based on bis(N-allylbenzimidazol-2-ylmethyl)
aniline: synthesis, crystal structures and antioxidative activity
Huilu Wu*, Han Zhang, Fei Wang, Hongping Peng, Yiming Cui, Yuanyuan Li and Yanhui Zhang
School of Chemical and Biological Engineering, Lanzhou Jiaotong University, Lanzhou, Gansu, 730070, P.R. China
Bis(N-allylbenzimidazol-2-ylmethyl)aniline (L) and its complexes, [Zn(L)(Cl) ] and [Co(L)(Cl) ], have been synthesised and the
2
2
structures of both complexes have been determined. [Zn(L)(Cl) ] can be described as distorted tetrahedron, while [Co(L)(Cl) ]
2
2
has a distorted trigonal bipyramidal geometry. In addition, the complexes were found to possess potent hydroxyl antioxidant
activity and be better than standard antioxidants like vitamin C and mannitol. In particular, [Co(L)(Cl) ] displayed excellent
2
activity towards the superoxide radical.
Keywords: bis(N-allylbenzimidazol-2-ylmethyl)aniline, Zn(II) and Co(II) complexes, crystal structure, antioxidative activity
Reactive oxygen species (ROS), such as superoxide anion O −•,
Nicolet FT-VERTEX 70 spectrometer using KBr pellets. Electronic
spectra were taken on a Lab-Tech UV Bluestar spectrophotometer.
2
−
•
hydrogen peroxide (H O ), and hydroxyl radical OH , are
2
2
generated by aerobic cells during normal oxygen metabolism.
Cumulative information obtained has proved that the
oxidation induced by ROS is involved in the pathogenesis of
various diseases, such as lifestyle-related diseases including
The absorbance was measured with a Spectrumlab 722sp
1
spectrophotometer at room temperature. H NMR spectra were
recorded on a Varian VR400-MHz spectrometer with TMS as an
internal standard. Electrolytic conductance measurements were made
–3
1,2
with a DDS-307 type conductivity bridge using 3×10 M solutions in
DMF at room temperature.
hypertension and photoaging due to exposure to UV radiation.
Whereas many superoxide and hydroxyl radicals are produced
3
The synthetic routine of ligand (L) 2 is shown in Scheme 1.
Bis(benzimidazol-2-ylmethyl)aniline (bba) (1): The ligand bba was
by the reduction of oxygen in the human body, overproduction
of free radicals is considered the main contributor to oxidative
stress. Many researchers have been working hard to develop
16,17
synthesised according to the procedure reported in the literature.
Yield 75.8%; m.p. 258–259 °C. Anal. calcd for C H N : C, 74.77; H,
4
,5
22 19
5
metal complexes in order to achieve efficient antioxidants.
Benzimidazole, typical heterocyclic ligand with
–1
5
7
(
.42; N, 19.82; found: C, 74.79; H, 5.41; N, 19.83%. IR (KBr; v/cm ):
44 ν(o-Ar), 1298 ν(C–N), 1445 ν(C=N), 1610 ν(C=C). H NMR
400 MHz, d -DMSO): δ 7.2–7.68 (m, 10H, benzimidazole), 6.55–7.10
a
1
nitrogen as the donor atom, is a useful intermediate for the
development of molecules of pharmaceutical or biological
6
(
m, 5H, Ph), 5.14(s, 4H CH ). UV-Vis (in DMF), λ (nm) 277 and 282.
6
2
m
a
x
interest. Benzimidazoles and their derivatives exhibit various
2
–1
Molar conductance: Λ (DMF solution, 297 K): 2.69 S·cm ·mol .
M
remarkable biological activities in such pharmaceuticals
Bis(N-allylbenzimidazol-2-ylmethyl)aniline (L) (2): Compound 1
7
8
9
10
as antiulcers, anthelmintics, antivirals, antifungals, and
(5.3 g, 0.015 mol) was suspended in dry tetrahydrofuran (150 mL) and
11
12–14
antihistamines, to name just a few.
Bis-benzimidazoles
stirred under reflux with potassium 1.17 g (0.03 mol). The solution
was stirred until the potassium disappeared, then allylbromide 3.63 g
have potent activity against a number of microorganisms
15
including those that lead to AIDS-related infections. We now
(0.03 mol) was added. After 1 h, the solvents were concentrated and
describe the synthesis and characterisation of the ligand L (2)
the resulting powder was washed with distilled water several times
to remove KBr. The solid substances were recrystallised with MeOH
and a pale-yellow powder bis(N-allylbenzimidazol-2-ylmethyl)
(
Scheme 1) and its transition metal complexes. The antioxidant
−
•
−•
activities (scavenging effects on O2 and OH ) of the ligand
and its complexes have also been studied. This information
obtained should be helpful in developing new antioxidants.
aniline (2) was deposited. Yield 79.7%; m.p. 170–173 °C. Anal. calcd
for C H N : C, 77.57; H, 6.28; N, 16.15; found: C, 77.60; H, 6.24; N,
2
8
27
5
–1
1
1
6.16%. IR (KBr; v/cm ): 744 ν(o-Ar), 1256 ν(C–N), 1444 ν(C=N),
600 ν(C=C). H NMR (400 MHz, d -DMSO): δ 7.18–8.0 (m, 8H,
Experimental
1
6
All chemicals and solvents were reagent grade and were used
without further purification. The C, H and N elemental analyses
were determined using a Carlo Erba 1106 elemental analyser.
benzimidazole), 7.18–6.83 (m, 5H, Ph), 4.5–4.87 (s, 4H, CH ), 4.87–6.0
2
–1
–1
(m, 10H, allyl). UV-Vis (in DMF), λ
(nm) [εmax (L·mol ·cm )]:
max
4
4
278(1.6×10 ), 285(1.52×10 ). Molar conductance: Λ (DMF solution):
M
–1
2
–1
The IR spectra were recorded in the 4000–400 cm region with a
2.1 S·cm ·mol .
Scheme 1 Synthesis of bba (1) and ligand (L) 2.
*
Correspondent. E-mail: wuhuilu@163.com

JOURNAL OF CHEMICAL RESEARCH 2015 77
Complex [Zn(L)(Cl) ] (3): ZnCl2 (68.15 mg, 0.50 mmol) in EtOH
10 mL) was added to a stirred solution of 2 (216.78 mg, 0.50 mmol)
methionine (MET) was used to produce the superoxide anion (O −•),
and the scavenging rate of O2 under the influence of 0.1–1.0 μM of
2
2
−
•
(
in hot EtOH (10 mL). A white crystalline product formed rapidly. The
the test compound was determined by monitoring the reduction in rate
of transformation of NBT to monoformazan dye. The solutions of
21
precipitate was filtered off, washed with EtOH and absolute Et O, and
2
dried under reduced pressure. The dried precipitate was dissolved in
MET, vitamin B and NBT were prepared in 0.02 M phosphate buffer
2
DMF to form a yellow solution into which Et O was allowed to diffuse
(pH=7.8) avoiding light. The reactions were monitored at 560 nm
with a UV-Vis spectrophotometer, and the rate of absorption change
was determined. The percentage inhibition of NBT reduction was
2
at room temperature. Crystals suitable for X-ray measurement were
obtained after several days. Complex 4 was prepared by a similar
procedure as for complex 3.
2
2
calculated using the following equation:
Complex 3: Yield 72%. Anal calcd for C H N ZnCl : C, 59.02; H,
.78; N, 12.29; found: C, 59.14; H, 4.73; N, 12.26%. IR (KBr; v/cm ):
2
8
27
5
2
percentage inhibition of NBT reduction=(1–k′/k)×100
–1
4
7
58 ν(o-Ar), 1264 ν(C–N), 1456 ν(C=N), 1597 ν(C=C). UV-Vis (in
where k′ and k are the slopes of the straight line of absorbance values
as a function of time in the presence and absence of SOD mimic
compound (SOD is superoxide dismutase), respectively. The IC50
values for the complexes were determined by plotting the graph of
percentage inhibition of NBT reduction against the concentration of
the complex. The concentration of the complex which causes 50%
inhibition of NBT reduction is reported as IC50.
–1
–1
4
4
DMF), λmax (nm) [εmax (L mol ·cm )]: 276(1.47×10 ), 280(1.46×10 ).
Molar conductance: Λ (DMF solution): 6.67 S·cm ·mol .
2
–1
M
Complex 4: Yield 80%. Anal calcd for C H N CoCl : C, 59.69; H,
2
8
27
5
2
–1
4.83; N, 12.43; found: C, 59.67; H, 4.85; N, 12.44%. IR (KBr; v/cm ):
756 ν(o-Ar), 1261 ν(C–N), 1454 ν(C=N), 1597 ν(C=C). UV-Vis (in
–1
–1
4
4
DMF), λmax (nm) [εmax (L mol cm )]: 275(1.64×10 ), 282(1.49×10 ),
6
2
–1
08(347). Molar conductance: Λ (DMF solution): 11.3 S·cm ·mol .
M
X-ray crystallography
Hydroxyl radical scavenging activity
Hydroxyl radicals were generated in aqueous media through the
Diffraction intensities for complexes 3 and 4 were collected on a
Bruker Smart CCD diffractometer with graphite-monochromated
18,19
Fenton-type reaction.
.0 mL of 0.10 mmol aqueous safranin, 1 mL of 1.0 mmol aqueous
EDTA–Fe(II), 1 mL of 3% aqueous H O , and a series of quantitative
The reaction mixture (3 mL) contained
Mo-K radiation (λ=0.71073 Å) at 296(2) K. Data reduction and cell
α
1
refinement were performed using the SMART and SAINT programs.
The structure was solved by direct methods and refined by full-matrix
2
2
microadditions of solutions of the test compound. A sample without
the tested compound was used as the control. The reaction mixtures
were incubated at 37 °C for 30 min in a water bath. The absorbance
was then measured at 520 nm. The scavenging effect for OH was
calculated from the following expression:
2
23
least-squares against F of data using SHELXTL software. All
H atoms attached to C atoms were fixed geometrically and treated
as riding with C–H=0.93 or 0.97 Å with U (H)=1.2 U (C). Basic
iso
eq
•
crystal data, description of the diffraction experiment, and details of
the refinement for complexes 3 and 4 are given in Table 1. Selected
bond lengths (Å) and angles (°) are presented in Table 2, respectively.
Scavenging effect (%)=(Asample – Ablank)/(Acontrol – Ablank)×100
where Asample is the absorbance of the sample in the presence of the
tested compound, Ablank is the absorbance of the blank in the absence of
the tested compound and Acontrol is the absorbance in the absence of the
Results and discussion
The synthetic route to ligand 2 is shown in Scheme 1. The
complexes were prepared by reaction of the ligand 2 with ZnCl2
2
0
tested compound and EDTA-Fe(II).
and CoCl in ethanol, respectively. All compounds are stable
2
Superoxide radical-scavenging activity
in air. They are soluble in polar aprotic solvents such as DMF,
DMSO and MeCN, slightly soluble in water, ethanol, ethyl
–
6
A nonenzymatic system containing 1 mL 9.9×10 M vitamin B2,
–
4
1
mL 1.38×10 M nitrotetrazolium blue chloride (NBT), 1 mL 0.03 M
acetate, and chloroform, and insoluble in Et O and petroleum
2
Table 1 Crystal and structure refinement data for complexes 3 and 4
Complex
Molecular formula
3
4
C H N ZnCl
C H N CoCl
2
2
8
27
5
2
28 27
5
Molecular weight
Crystal system
Space group
569.82
Triclinic
P-1
9.4888(10)
10.6798(11)
13.1005(13)
563.38
Monoclinic
P2(1)/c
8.805(13)
14.55(2)
21.00(3)
100.059(17)
2649(7)
4
a/Å
b/Å
c/Å
β/º
96.8020(10)
1288.6(2)
3
V/Å
Z
2
−
3
D(calcd)/g·cm
F (000)
1.469
588
1.412
1164
Crystal size/mm
θ range for data collection
h/k/l (max, min)
Reflections collected
Independent reflections
Refinement method
Data/restraints/parameters
0.40×0.38×0.30
1.60–25.49
–11,11/–12,12/–15,15
8882
0.39×0.38×0.29
1.71–25.50
–10,10/–16,17/–25,25
16323
4677/0.0168
Full–matrix least–squares on F
4677/0/325
1.135
4887/0.0784
Full–matrix least–squares on F
4887/7/325
2
2
2
Goodness-of-fit on F
1.001
Final R , wR indices [I>2σ(I)]
0.0274/0.0756
0.0313/0.086
0.258/–0.325
0.0671/0.1852
0.1061/0.2238
0.695/–0.698
1
2
R ,wR indices (all data)
1
2
–
3
Largest differences peak and hole/eÅ

78 JOURNAL OF CHEMICAL RESEARCH 2015
Table 2 Selected bond distances (Å) and angles (°) for complexes 3 and 4
in the spectra of the complexes, which is evidence of C=N
coordination to the metal centre. These bands are assigned to
n→π* and π→π* (imidazole) transitions.
3
2
7,28
Zn(1)–N(5)
Zn(1)–Cl(1)
2.056(2)
2.2588(7)
Zn(1)–N(3)
Zn(1)–Cl(2)
2.0646(19)
2.2642(7)
Crystal structure of complex 3
N(5)–Zn(1)–N(3)
N(3)–Zn(1)–Cl(1) 104.46(6)
N(3)–Zn(1)–Cl(2) 109.00(6)
109.33(8)
N(5)–Zn(1)–Cl(1) 123.47(6)
N(5)–Zn(1)–Cl(2) 102.01(6)
Cl(1)–Zn(1)–Cl(2) 108.08(3)
The single-crystal X-ray structure of complex 3 with atom
labelling is shown in Fig. 1. The selected bond lengths and
bond angles are listed in Table 2. The metal atom is coordinated
N(5)–Zn(1)–N(1)
Cl(1)–Zn(1)–N(1)
67.79(7)
84.79(4)
N(3)–Zn(1)–N(1)
Cl(2)–Zn(1)–N(1) 166.91(4)
68.77(7)
with an N Cl ligand set, of which two are N atoms [N(3), N(5)]
2
2
afforded by the ligand 2, and the other two are chloride atoms
C1(1),Cl(2)].Thecoordinationgeometryofthezinc(II)maybest
4
[
Co(1)–N(5)
Co(1)–Cl(2)
Co(1)–N(1)
N(5)–Co(1)–N(3)
N(3)–Co(1)–Cl(2)
N(3)–Co(1)–Cl(1)
N(5)–Co(1)–N(1)
Cl(2)–Co(1)–N(1)
2.041(4)
2.268(3)
2.623(5)
110.73(17)
111.77(15)
105.52(14)
71.50(16)
87.33(12)
Co(1)–N(3)
Co(1)–Cl(1)
2.080(5)
2.314(3)
be described as distorted tetrahedral. Three bonds Zn(1)–N(3),
Zn(1)–N(5) and Zn(1)–Cl(1) are formed in the pyramidal
bottom plane; the distances are within the range 2.056(2) Å
and 2.2588(7) Å. The bond distance between the Zn(1) and the
apical Cl(2) is 2.2642(7) Å, and the bond distances between
the Zn ion and the basal atoms are [Zn(1)–N(3)=2.0646(19) Å,
Zn(1)–N(5)=2.056(2) Å and Zn(1)–Cl(1)=2.2588(7) Å]. Owing
to this coordination geometry, an eight-membered ring results,
which is connected through the Zn(II) centre and displays an
eight-shaped geometry.
N(5)–Co(1)–Cl(2) 122.51(14)
N(5)–Co(1)–Cl(1) 100.42(15)
Cl(2)–Co(1)–Cl(1) 103.51(11)
N(3)–Co(1)–N(1)
Cl(1)–Co(1)–N(1) 168.97(10)
71.56(16)
−1
Table 3 IR bonds (cm ) of compounds
Compounds
v(Ar)
v(C–N)
v(C=N)
v(C=C)
As shown in Fig. 2, weak supramolecular π···π and strong
C–H···Cl hydrogen-bonding interactions play important roles
2
3
4
744
758
756
1256
1264
1261
1444
1456
1454
1601
1597
1597
2
9
in the crystal packing modes in the complex. The planes of two
benzimidazole rings form π···π stacking interactions (centroid-
to-centroid distances: 3.700 Å) along the crystallographic ac
axis. Such an arrangement can make the crystal structure more
stable.
ether. The elemental analyses show their different compositions
and their molar conductivities in DMF solution indicate that
they are non-electrolytes.
Crystal structure of complex 4
IR and UV-Vis spectra
The IR spectra data for ligand 2 and its complexes, along with
their relative assignments, are given in Table 3. In the free
ligand, a strong band is found around 1260 cm along with
another less strong band around 1450 cm . By analogy with the
Complex 4 crystallised in the monoclinic space group P2(1)/c
(Fig. 3). The molecular structure consists of a ligand of 2,
two chloride atoms, and one Co(II) atom. The ligand 2 is a
terdentate N-donor, and two chloride ion of a monodentate
salicylate complete the coordination. The coordination of
the Co(II) atom may be best described as distorted trigonal
−
1
−1
spectrum of imidazole, the former is attributed to v(C–N), while
2
4,25
−1
the other one is v(C=N).
One shifts around 10 cm and the
bipyramidal (τ =0.77), with approximate C3 symmetry. The
1
−1
other at around 5 cm in both complexes, which implies direct
coordination of both imine nitrogen atoms to metal ions. There
are the preferred nitrogen atoms for coordination, as found in
parameter τ is defined as (β–α)/60 [where β=Cl(1)–Co(1)–N(1),
α=N(5)–Co(1)–Cl(2)] and its value varies from 0 (in
regular square-based pyramidal) to 1 (in regular trigonal
2
6
30
other metal complexes with benzimidazoles. This observation
agrees with the results determined by X-ray diffraction.
DMF solutions of ligand 2 and its complexes show, as
expected, almost identical UV spectra. The UV bands of
bipyramidal). The axial sites are occupied by N(1) and Cl(1),
with Co(1)–N(1)=2.623(5) Å, Co(1)–Cl(1)=2.314(3) Å and
Cl(1)–Co(1)–N(1)=168.97(10)°. The trigonal plane is occupied
by a ligating N atoms of the benzimidazolyl groups and two
chloride atoms, namely atoms N(3)/N(5)/Cl(2). The angles
2
(278, 285 nm) are only marginally blue-shifted (2–5 nm)
Fig. 1 Molecular structure of complex 3 with hydrogen atoms were omitted for clarity.

JOURNAL OF CHEMICAL RESEARCH 2015 79
Fig. 2 2-D layer generated by the π···π interactions in the ac plane in complex 3 (for clarity, some atoms are omitted).
Fig. 3 Molecular structure and atom-numberings of complex 4 with hydrogen atoms omitted for clarity.
N(5)–Co(1)–N(3), N(3)–Co(1)–Cl(2) and N(5)–Co(1)–Cl(2)
are 110.73(17)°, 111.77(15)° and 122.51(14)°, respectively. The
N(3)–Co(1)–N(1) = 71.56(16)°, N(5)–Co(1)–N(1) = 71.50(16)°
and Cl(2)–Co(1)–N(1)=87.33(12)° angles appear essentially
imposed by the stereochemistry of the ligand L and chloride
atom.
As one of the important types of supramolecular forces, π···π
stacking shows a specific structural requirement for substrate
recognition or the arrangement of complicated architectures.
In complex 4, the centroid-to-centroid distance of 3.581 Å
between the two nearly parallel planes of the benzimidazole
rings indicates weak intramolecular interactions (Fig. 4). The
same time. The intramolecular weak interactions also help to
assemble the crystal structures into different dimensions.
Antioxidant activities
6
,16
It is well-documented that some transition metal complexes
display significant antioxidant activity. Consequently, in this
paper, 2 and its complexes were studied for their antioxidant
−
•
activity by comparing their scavenging effects on OH and
−
•
O2
.
Hydroxyl radical scavenging activity
We compared the abilities of the present compounds to
scavenge hydroxyl radicals with those of the well-known
natural antioxidants mannitol and vitamin C, using the
2
D structure was formed through π···π interactions and weak
18,31
C–H···Cl hydrogen bonding between benzimidazole and
chloride anion in adjacent chains.
From the above crystal structures of complexes, we have
found that their structural conformations were mainly
controlled by the ligand and metal centres, and also influenced
by the coordination capabilities of counter anions at the
same method as reported previously.
The 50% inhibitory
concentration (IC ) values of mannitol and vitamin C are about
5
0
–3
–3
9.6×10 and 8.7×10 M, respectively. Figure 5 shows the plots
of hydroxyl radical scavenging effect (%) for complexes 3 and
−
5
4, and the IC values of complexes 3 and 4 are 2.92×10
M
5
0
−
5
and 4.47×10 M, respectively, but the ligand 2 does not have

8
0 JOURNAL OF CHEMICAL RESEARCH 2015
Fig. 4 The π···π interactions and packing modes in complex 4 (H atoms are omitted).
–
5
activity. The result indicates that the binding strength of the
two complexes follow the order: 3>4, which imply that the two
complexes exhibit better scavenging activity than mannitol and
vitamin C. The lower IC values observed in antioxidant assays
seen from Fig. 6, the IC50 value of complex 4 is 5.05×10 M,
but complex 3 does not have activity. The result indicates that
complex 4 exhibits good superoxide radical-scavenging activity
and may be an inhibitor (or a drug) to scavenge superoxide
5
0
−
•
radical (O ) in vivo which need further investigation.
demonstrate that the two complexes have a strong potential to
2
32
be applied as scavengers to eliminate radicals.
Conclusions
Superoxide radical scavenging activity
In summary, the ligand 2 and its complexes 3 and 4 have been
synthesised and the structures and geometry of complexes 3
and 4 were analysed through single crystal X-ray diffraction.
The complex 3 can be described as distorted tetrahedron. The
geometric structure of complex 4 may be treated as distorted
trigonal bipyramidal. Furthermore, complexes 3 and 4 were
found to possess potent hydroxyl radical scavenging activity
and be better than standard antioxidants like vitamin C and
mannitol. Furthermore, the complexes possess significant
superoxide radical activity. These findings indicate that
complexes 3 and 4 have potential practical applications in the
development of antioxidants, which warrants further in vivo
experiments and pharmacological assays.
As another assay of antioxidant activity, superoxide radical
−
•
33,34
(
O )-scavenging activity has been investigated.
As can be
2
(a)
Crystallographic data for complexes 3 and 4 have been
deposited with the Cambridge Crystallographic Data Centre
as CCDC1005343 and 1005342, respectively. The data can
be obtained free of charge from the CCDC, 12 Union Road,
Cambridge CB2 1EZ, UK. Tel: +44 1223 762910; fax: +44 1223
336033; E-mail: deposit@ccdc.cam.ac.uk or http://www.ccdc.
cam.ac.uk.
(b)
Fig. 5 The inhibitory effect of complex 3 (a) and complex 4 (b) on OH−•
radicals; the suppression ratio increases with increasing concentration of
the test compounds.
Fig. 6 The superoxide radical scavenging effect (%) for complex 4.

JOURNAL OF CHEMICAL RESEARCH 2015 81
The present research was supported by the National Natural
Science Foundation of China (Grant No. 21367017), the
Fundamental Research Funds for the Gansu Province
Universities (212086), Natural Science Foundation of Gansu
Province (Grant No. 1212RJZA037), and ‘Qing Lan’ Talent
Engineering Funds for Lanzhou Jiaotong University.
14 S.M. Sondhi, S. Rajvanshi, M. Johar, N. Bharti, A. Azam and A.K. Singh,
Eur. J. Med. Chem., 2002, 37, 835.
15
C.A. Bell, C. Dykstra, N.A. Naimen, M. Cory, T.A. Fairley and R.R.
Tidwell, Antimicrob. Agents Chemother., 1993, 37, 2668.
16
H.L. Wu, B. Liu, F. Kou, F. Jia, J.K. Yuan and Y. Bai, J. Chin. Chem. Soc.,
2
012, 59, 836.
17
R. Cariou, J.J. Chirinos, V.C. Gibson, G. Jacobsen, A.K. Tomov, G.J.P.
Britovsek and A.J.P. White, Dalton Trans., 2010, 39, 9039.
Received 27 November 2014; accepted 4 January 2015
Paper 1403045 doi:10.3184/174751915X14210834541638
Published online: 13 February 2015
1
8
S. Satyanarayana, J.C. Daborusak and J.B. Chaires. Biochem., 1993, 32,
2
573.
19 C.P. Tan, J. Liu, L.M. Chen, S. Shi and L.N. Ji, J. Inorg. Biochem., 2008,
02, 1644.
1
2
0
Z.Y. Guo, R.E. Xing, S. Liu, H.H. Yu, P.B. Wang, C.P. Li and P.-C. Li,
Bioorg. Med. Chem. Lett., 2005, 15, 4600.
X.Y. Le, S.R. Liao, X.P. Liu and X.L. Feng, J. Coord. Chem., 2006, 59, 985.
Q.H. Luo, Q. Lu, A.B. Dai and L.G. Huang, J. Inorg. Biochem., 1993, 51,
References
1
2
R.M. Towyz, Hypertension, 2004, 44, 248.
T. Fujimori, S. Yamada, H. Yasui, H. Sakurai, Y. In and T. Ishida, J. Biol.
Inorg. Chem., 2005, 10, 831.
2
1
2
2
655.
3
4
A. Banerjee, N. Dasgupta and B. De, Food Chem., 2005, 90, 727.
V. Siddaiah, C.V. Rao, S. Venkateswarlu, A.V. Krishnaraju and G.V.
Subbaraju, Bioorg. Med. Chem., 2006, 14, 2545.
2
3
G.M. Sheldrick, SHELXTL, Siemens Analytical X‑ray Instruments, Inc.,
Madison, Wisconsin, 1996.
S.C. Yang and W.B. Tzeng, Chem. Phys. Lett., 2010, 501, 6.
X.F. Guo, Z.F. Li, C. Yue, G. Li, Y.C. Gao and Y. Zhu, Polyhedron, 2010,
29, 384.
2
2
4
5
5
6
7
8
J.L. Pierre, P. Chautemps, S. Refaif, C. Beguin, A.E. Marzouki, G.
Serratricel, E. Saint-Aman and P. Rey, J. Am. Chem. Soc., 1995, 117, 1965.
H.L. Wu, J.K. Yuan, Y. Bai, G.L. Pan, H. Wang, J. Kong, X.Y. Fan and
H.M. Liu, Dalton Trans., 2012, 41, 8829.
J. Velik, V. Baliharova, J. Fink-Gremmels, S. Bull, J. Lamka and L.
Skalova, Res. Vet. Sci., 2004, 76, 95.
26 R. Bakshi and P. Mathur, Inorg. Chim. Acta, 2010, 363, 3477.
27 F.Z.C. Fellah, J.P. Costes, C. Duhayon, J.C. Daran and J.P. Tuchagues,
Polyhedron, 2010, 29, 2111.
28 H.L. Wu, H.C. Huang, J.K. Yuan, F. Kou, G.S. Chen, B.B. Jia, Y. Yang and
Y.L. Lai, Z. Naturforsch., B., 2010, 65, 1334.
M. Devereux, D.O. Shea, A. Kellett, M. McCann, M. Walsh, D. Egan, C.
Deegan, K. Kędziora, G. Rosair and H. Müller-Bunz, J. Inorg. Biochem.,
2
007, 101, 881.
29
D. Kang, J. Seo, S.Y. Lee, J.Y. Lee, K.S. Choi and S.S. Lee, Inorg. Chem.
Commun., 2007, 10, 1425.
S. Youngme, J. Phatchimkun, U. Sukangpanya, C. Pakawatchai, N.
Chaichit, P. Kongsaeree, J. Krzystek and B. Murphy, Polyhedron, 2007,
9
J. Mann, A. Baron, Y. Opoku-Boahen, E. Johansson, G. Parkinson, L.R.
Kelland and S. Neidle, J. Med. Chem., 2001, 44, 138.
3
0
10
J. Cheng, J.T. Xie and X.J. Luo, Bioorg. Med. Chem. Lett., 2005, 15, 267.
11 A. Gellis, H. Kovacic, N. Boufatah and P. Vanelle, Eur. J. Med. Chem.,
2
6, 871.
2
008, 43, 1858.
31
H.L. Wu, J.K. Yuan, G.L. Pan, Y.H. Zhang, X.L. Wang, F.R. Shi and X.Y.
Fan J. Photochem. Photobiol. B, 2013, 122, 37.
Y. Wang, Z.Y. Yang and B.D. Wang, Trans. Met. Chem., 2005, 30, 879.
12
O.O. Guven, T. Erdogan, H. Goker and S. Yildiz, Bioorg. Med. Chem.
Lett., 2007, 17, 2233.
32
13
H. Torres-Gomez, E. Hernandez-Nuez, I. Leon-Rivera, J. Guerrero-
Alvarez, R. Cedillo-Rivera, R. Moo-Puc, R. Argotte-Ramos, M.C.
Rodriguez-Gutierrez, M.J. Chan-Bacab and G. Navarrete-Vazquez,
Bioorg. Med. Chem. Lett., 2008, 18, 3147.
33 B.D. Wang, Z.Y. Yang, P. Crewdson and D.D. Wang, J. Inorg. Biochem.,
2007, 101, 1492.
34 H.L. Wang, Z.Y. Yang and B.D. Wang, Trans. Met. Chem., 2006, 31, 470.

Copyright of Journal of Chemical Research is the property of Science Reviews 2000 Ltd. and
its content may not be copied or emailed to multiple sites or posted to a listserv without the
copyright holder's express written permission. However, users may print, download, or email
articles for individual use.