Organotin(IV) complexes of 4,5-dimethoxy-2-nitrobenzoic acid: Synthesis, characterization, and biological activity

Article abstract of DOI:10.1134/S1070328409120069

A new series of organotin esters has been derived from the condensation of organotin oxides/halides with 4,5-dimethoxy-2-nitrobenzoic acid. Their spectroscopic investigations have been carried out both in solution and solid state. Experimental details for

Full text of DOI:10.1134/S1070328409120069

ISSN 1070-3284, Russian Journal of Coordination Chemistry, 2009, Vol. 35, No. 12, pp. 896–902. © Pleiades Publishing, Ltd., 2009.
Organotin(IV) Complexes of 4,5-Dimethoxy-2-Nitrobenzoic
Acid: Synthesis, Characterization, and Biological Activity1
F. A. Shaha, S. Shahzadib, S. Alia,*, K. C. Molloyc, and S. Ahmada
a Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan
b Department of Chemistry, GC University, Faisalabad, Pakistan
c Department of Chemistry, University of Bath, Bath BA2 7AY, UK
*e-mail: drsa54@yahoo.com
Received March 18, 2009
Abstract—A new series of organotin esters has been derived from the condensation of organotin oxides/halides
with 4,5-dimethoxy-2-nitrobenzoic acid. Their spectroscopic investigations have been carried out both in solu-
tion and solid state. Experimental details for the preparation and the structural characterization (by FTIR, NMR,
XRD, and EI mass spectral analysis) are provided. Based on spectroscopic results, the ligand appeared to coor-
dinate to the Sn atom through the COO moiety. Single crystal analysis has shown a bridging behavior of ligand
in tributyltin(lV) derivative. Bioassay results have shown that these compounds have good antibacterial, anti-
fungal and cytotoxicity activity, with few exceptions.
DOI: 10.1134/S1070328409120069
1
9COOH
INTRODUCTION
1
NO2
Organotin carboxylates attract considerable atten-
tion due to their wide range of applications. Extensive
use of organotin compounds in various fields of life
results in quantum leap of organotin chemistry. Their
stability and structure diversity make their coordination
chemistry very interesting [1]. Organotin derivatives
act as potentially active biological agents and have a
great impact in biosphere [2–4]. Their importance and
applications in the agriculture field and industries are
well documented [5, 6].
6
2
3
5
H3CO
4
8
OCH3
7
EXPERIMENTAL
Materials and instrumentation. All chemicals
used were of analytical grade. HL and organotin(IV)
chlorides were purchased from Aldrich, while organo-
tin oxides was from Alfa Aesar. These chemicals were
used without further purification. The solvents were
dried in situ according to a standard procedure [17]. All
the reactions were carried out under argon atmosphere
in dry toluene. Melting points were determined by
using an Electro thermal based melting point apparatus
model MP-D mitamura Riken Kogyo (Japan) and were
uncorrected. IR spectra were recorded as KBr pallets
on a Bio-Red Excaliber FT-IR, model 3000 MX Spec-
trum in the range of 4000–400 cm–1. Mass data were
recorded on a mass spectrometer model JMS 600H
using the direct probe method and EI+ as a source of
ionization. NMR spectra were recorded on a Bruker
300 MHz spectrometer, using CDCl3 as an internal ref-
erence. C, H, N analyses were performed with an
organic elemental analyzer (model EA 1110, CE
Instrument, Italy).
A structure-activity relationship of organotin com-
plexes has been explored using different carboxylate
ligand [7–9]. The biological activity of the organotin
compounds is probably due to the presence of easily
hydrolysable groups yielding the intermediates, such as
RnSn4 – n (n = 2 or 3) moieties, which may bind with
DNA [10], high as well as low affinity site of ATPase or
haemoglobins [11, 12]. Although triorganotin com-
pounds are commercially important as biocides, yet
these also exhibit an interesting range of structural vari-
ations that may help to establish a structure-activity
relationship [13]. The present work is the continuation
of our interest in synthesis, characterization, and appli-
cations of organotin carboxylates [14–16]. We report
here synthesis, characterization, and biological applica-
tions of organotin(IV) complexes of 4,5-dimethoxy-2-
nitrobenzoic acid (HL).
Synthesis of triorganotin carboxylates. HL
(1 mmol) was dissolved in dry chloroform in a two-
1
The article is published in the original.
896

ORGANOTIN(IV) COMPLEXES OF 4,5-DIMETHOXY-2-NITROBENZOIC ACID
Table 1. Elemental analysis data and some physical properties of HL and organotin(IV) compounds I–VII
Contents (calcd/found), %
897
Compound
M.p., °C
Yield, %
Molecular weight
C
H
N
HL
200
58
227
390
516
576
601
685
725
789
I
78
80
80
77
75
72
80
36.92/36.87
48.83/48.93
56.25/56.33
39.93/39.85
45.54/45.44
49.65/49.73
51.71/51.80
4.35/4.41
6.78/6.70
3.99/3.89
3.66/3.72
4.96/4.88
3.58/3.64
5.32/5.41
3.58/3.62
2.71/2.79
2.43/2.33
4.65/4.72
4.08/4.19
3.86/3.97
3.54/3.63
II
185
168
112
130
170
68
III
IV
V
VI
VII
necked flask, and equimolar triethylamine (1 mmol) deprotonation of the carboxylic acid group. The differ-
was added to it. The mixture was refluxed for 30 min. ence between νas(COO) and νs(COO), i.e., Δν is impor-
Then stoichiometric amount of triorganotin chloride tant in the prediction of nature of the binding mode of
was added to this solution and refluxed for 4–7 h. The the ligand and indicative of the coordination number
reaction mixture was kept at room temperature over- around tin [18, 19].
As the value of difference Δν is less than 200 cm–1,
night. The precipitated Et3NHCl was then filtered off,
and the solvent was evaporated under reduced pressure.
The crude mass left behind was crystallized from an
appropriate chloroform-n-hexane mixture (1 : 1).
it suggests that the ligand behaves as bidentate toward
the tin atom. The bands obtained in a range of 547–
547–566 cm–1 are assigned to Sn–C bonds, whereas
additional absorption in the range of 435–448 cm–1
shows the presence of Sn-O vibrations in these com-
plexes.
R3SnCl + HL + Et3N
R3SnL + Et3NHCl,
R = Me (I), n-Bu (II), Ph (III).
Synthesis of diorganotin dicarboxylates. Stoichi-
ometric amounts of carboxylic acid and organotin
oxide were mixed in a single-neck flask in dry toluene
and refluxed for 6–7 h in a round-bottom two-necked
flask. Water formed during the reaction was continu-
ously removed using a Dean-Stark apparatus. A yellow,
transparent solution was obtained. Solvent was evapo-
rated under reduced pressure by using a rotary evapora-
tor. The mass left behind was crystallized from CHCl3-
acetone (1 : 1).
The NMR signals are assigned by their intensity,
multiplicity pattern, as well as their coupling constants
and/or tin satellites. Their integration is in accordance
with the composition expected for different fragments
of the molecule.
1
The H NMR spectra of the above reported com-
plexes I−VII in a CDCl3 solution show the absence of
carboxylic proton, which was replaced by the organotin
moiety. This information agrees well with what the IR
data have revealed. All the protons in the reported com-
R2SnO + 2HL
R2SnL2 + H2O,
R = Me (IV), n-Bu (V), Ph (VI), n-Oct (VII).
Table 2. Characteristic infrared bands of organotin(IV) com-
pounds (cm–1)
All the compounds I−VII were yellow in color, and
obtained in more than 70% yield with melting point in
the range of 58–185°C. These are fairly soluble in
organic solvents like CHCl3, DMSO, and THF. Physical
data are given in Table 1.
Compound νas(COO) νs(COO) Δν ν(Sn–C) ν(Sn–O)
HL
I
II
III
IV
V
VI
VII
1500
1526
1518
1518
1528
1528
1508
1522
1389
1379
1360
1375
1355
1376
1363
1373
211
147
158
143
173
152
145
149
563
547
564
565
566
563
554
440
446
448
435
448
445
448
RESULTS AND DISCUSSION
The IR spectra of complexes are compared with the
spectrum of HL, and the important bands for structure
assignment are given in Table 2. The complexation of
ligand with tin is confirmed by the absence of a broad
band at 3210 cm–1 due to ν(OH), thus showing the
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 35 No. 12 2009

898
SHAH et al.
Table 3. 1H NMR data of organotin carboxylates I–VII*
Compound
Proton
I
II
7.42 s.
III
IV
V
VI
VII
7.41 s.
3
6
7
8
α
β
γ
7.38 s.
7.99 s.
7.98 s.
3.00 s.
2.98 s.
7.70 m.
7.45 m.
7.75 m.
8.72 s.
7.28 s.
7.41 s.
7.28 s.
3.95 s.
3.88 s.
7.39 m.
7.30 m.
7.45 m.
7.28 s.
7.28 s.
7.46 s.
7.23 s.
7.27 s.
3.99 s.
3.17 s.
3.19 s.
3.13 s.
3.98 s.
3.97 s.
3.14 s.
3.16 s.
3.10 s.
3.96 s.
0.97 s. [58]
1.41–1.35 m.
1.25–1.30 m.
0.78 (t., 7.0)
0.06 s. [77]
2.20–1.98 m.
1.75–1.80 m.
1.00 (t., 7.0)
0.86–1.95 m.
n
1
1
n
119
1
* Chemical shift in ppm, J ( H– H); J ( Sn– H) in Hz.
Table 4. 13C NMR data of organotin carboxylates I–VII*
Compound
Carbon atom
I
II
III
IV
V
VI
VII
1
124.4
125.7
127.3
143.7
112.2
151.5
150.9
127.4
55.1
127.9
148.9
110.5
152.5
151.9
126.7
56.5
126.9
143.5
111.7
151.7
151.2
119.9
55.5
120.2
143.0
111.3
152.1
150.9
106.9
56.7
119.3
139.1
104.4
149.6
147.8
108.4
54.1
2
141.4
140.5
3
110.9
110.5
4
152.0
152.4
5
149.5
149.2
6
112.7
106.6
7
56.53
56.6
8
56.51
56.5
55.0
56.4
55.2
56.4
54.0
9
170.5
176.5
173.1
138.5
137.4
136.3
130.7
174.0
29.6
175.3
29.3
179.4
129.9
127.5
126.4
125.3
176.0
37.2 [556]
31.2 [36]
30.0
α
β
14.02 [394]
29.6 [360]
27.4 [22]
26.8 [63]
14.5
27.7 [21]
γ
26.5
14.6
δ
29.3
α*
β*
γ*
δ*
29.1
26.7
22.4
14.1
n
119
13
* Chemical shift in ppm. Coupling J ( Sn– C) in Hz.
plexes have been identified at position and number with 1.95 ppm, which are consistent with the values calcu-
lated by the incremental method [20].
The aromatic carbon resonances are assigned by the
comparison of experimental chemical shift with those
protons calculated from the incremental method [20].
1H NMR data are given in Table 3. The methyl protons
of I appear as sharp singlet at 0.97 ppm with nJ (119Sn–1H)
coupling of 58.0 Hz. The methylene protons (CH2) of calculated from the incremental method [20] or com-
pared with literature data [8].
n-octyltin(IV) moiety exhibit somewhat different
behavior compared with the n-butyl groups of the
respective complexes. The α-CH2, β-CH2, and γ-CH2 to
The carboxylate carbon shifts to the lower-field
region in all complexes I−VII indicating participation
γ'-CH2 protons give broad/multiplet signals at 0.86– of the carbonyl group COO in coordination to tin(IV)
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 35 No. 12 2009

ORGANOTIN(IV) COMPLEXES OF 4,5-DIMETHOXY-2-NITROBENZOIC ACID
899
Table 5. Mass spectral data of organotin(IV) compounds I–VII
II III
I
IV
V
VI
VII
Fragment/ion
m/z (%)
R2SnL
SnL
460(8)
302(12)
291(8)
234(10)
177(8)
120(80)
500(100)
302(25)
348(18)
272(8)
460(8)
572(8)
302(100)
165(12)
150(17)
135(38)
120(8)
302(4)
302(100)
302(13)
302(70)
R3Sn+
R2Sn+
RSn+
Sn+
150(12)
135(28)
120(12)
234(9)
272(11)
196(12)
120(52)
346(8)
233(4)
120(7)
196(82)
120(65)
177(12)
120(10)
C9H8NO+
226(65)
86(12)
226(82)
86(100)
226(15)
86(32)
226(12)
86(100)
226(38)
86(2)
226(100)
86(67)
226(73)
86(32)
6
C7H+
2
C4H+
75(60)
211(9)
57(50)
211(8)
57(3)
211(8)
180(6)
57(14)
211(8)
57(50)
211(8)
180(8)
57(45)
211(8)
180(21)
75(100)
211(8)
9
C4H11O2NSn+
C9H8O+
180(21)
180(27)
180(24)
180(18)
4
C7H2O+
124(41)
93(16)
124(3)
93(32)
124(10)
93(12)
124(51)
93(26)
124(19)
93(11)
124(45)
93(16)
124(36)
93(18)
2
C6H5O+
[21]. The coupling constants nJ (119Sn, 13C) are impor- to be more active than the diorganotin derivatives, and
tant parameters for the structural characterization of the behavior is quite consistent with earlier report [29].
organotin(IV) compounds and data is given in Table 4.
The activity varies with variation of the R groups
For triorganotin(IV) compounds, the magnitude of
attached to Sn. Apparently, the function of the ligand is
1J (119Sn, 13C) coupling suggests the tetrahedral geome-
to support the transport of the active organotin moiety
to the site of action, where it is released by hydrolysis
try around the tin atom in solution [22, 23]. As far as
geometry of the diorganotin dicarboxylates in non-
[30].
coordinating solvents is concerned, it is not defined
The synthesized complexes were tested for their
antibacterial activity, using the agar well diffusion
method [28]. The ligand and complexes I−IV, VI, VII
were found to be inactive against all bacteria except
complex I, II, V, and VII versus bacteria Psendomonas
with certainty due to the fluxional behavior of the car-
boxylate oxygen in their coordination with the tin atom
[24]. However, the earlier reports suggest geometry in
between penta- and hexacoordination [25, 26].
Mass spectrometry was carried out using electron
beam of 70 eV. The major fragments along with their
m/z and relative abundances are given in Table 5. The
mass fragmentation pattern follows our previously
established route [27]. In triorganotin and diorganotin
derivatives no molecular ion peak is observed. The
fragment ions are in good agreement with the expected
structure of the compounds.
Table 6. Antifungal data of organotin(IV) compounds*
Name of fungus
HL
I
II
III
Trichphyton longifusus
Candida albicans
Aspergillus flavus
Microsporum canis
Fusarium solani
0
0
80
0
80
0
80
90
0
45
0
90
80
90
0
40
80
0
The complexes were checked for antifungal activity
against different plant pathogens by using theAgar tube
dilution protocol [28], and the data collected are listed
in Table 6. Generally, all derivatives show markedly
higher antifungal activity than the ligand with few
exceptions. The triorganotin(IV) derivatives are found
70
75
90
0
Candida glabrata
0
0
* Complexes IV–VII shows no antifungal activity (except complex VI
versus fungus Fusarium solani (40)).
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 35 No. 12 2009

900
SHAH et al.
C(24)
C(23)
C(22)
C(21)
C(61)
O(6)
C(7)
O(1)
C(1)
Sn
C(31)
C(6)
C(5)
O(5)
C(51)
C(33)
C(32)
O(2)
C(31A)
C(11)
C(32A)
C(34A)
C(2)
C(4)
N
O(3)
C(3)
C(33A)
C(34)
C(12)
C(14)
C(4)
C(13)
Fig. 1. ORTEP drawing of the X-ray structure of compound II.
C(23)
C(24)
C(22)
O(2-4)
C(31)
C(33)
C(32)
C(21)
C(34)
Sn
C(11)
C(61)
O(1)
C(2)
C(12)
C(13)
C(7)
C(1)
O(6)
O(2)
C(6)
C(5)
O(5)
C(14)
N
C(3)
C(4)
O(3)
C(51)
O(4)
Fig. 2. Refined ORTEP drawing of the X-ray structure of compound II.
aeruginosa (13, 12, 15, and 15, respectively). Complex the anionic ligand group that generally plays a second-
ary role.
V is active against all bacteria, for example Eschericha
coli, Bacillus subtilis, Shigella flexenari, Staphylococcus
aureus, Pseudomonas aeruginosa, and Salmonella typhi
(13, 15, 15, 15, 15 and 14, respectively). In the present
study, the triorganotin(IV) derivatives are found to be
more active than the diorganotin(IV) derivatives. This
situation is in sharp contrast to the earlier assessment
that an increase in the number of R groups on the
The complexes were also screened for cytotoxicity
data, using the Brine-shrimp (Artemia salina) bioassay
lethality method [28]. The data show that ligand and
compounds I−III and V−VIII shows no cytotoxicity.
However, compound IV shows and LD50 value of
0.0255 μg/ml and exhibits significant toxicity.
The molecular structure of complex II is shown in
tin(IV) atom enhances its biological activity. This Fig. 1. The complexes exhibit a carboxylate-bridged
motif in which the Sn center shows trans-Bu3SnO2 trig-
anomalous behavior can be explained on the basis of
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 35 No. 12 2009

ORGANOTIN(IV) COMPLEXES OF 4,5-DIMETHOXY-2-NITROBENZOIC ACID
901
Table 7. Crystal data and structure refinement for compound II Table 8. Selected bond lengths and bond angles for compound II
Parameter
Value
Bond
Sn–C(31)
d, Å
Bond
d, Å
Empirical formula
Formula weight
Temperature, K
Wavelength, Å
Crystal system
Space group
Unit cell dimensions:
a, Å
C21H35NO6Sn
516.19
2.133(7)
2.137(3)
C(31)–C(32)
C(32)–C(33)
1.580(15)
1.47(3)
Sn–C(11)
150(2)
Sn–O(2)
2.2031(17) C(33)–C(34)
1.52(2)
0.71073
Monoclinic
P21/a
Sn–O(1)
2.4158(17) C(31A)–C(32A) 1.481(14)
C(11)–C(12)
C(12)–C(13)
C(13)–C(14)
C(21)–C(22)
C(22)–C(23)
C(23)–C(24)
1.518(4)
1.535(4)
1.514(5)
1.527(4)
1.517(6)
1.532(5)
C(32A)–C(33A) 1.56(2)
C(33A)–C(34A) 1.480(17)
O(1)–C(1)
O(2)–C(1)
O(2)–Sn
1.250(3)
1.268(3)
2.2031(17)
10.6065(2)
18.9480(4)
12.1146(3)
94.7700(10)
2426.26(9)
4
b, Å
c, Å
β, deg
Angle
ω, deg
Angle
ω, deg
V, Å3
C(31)SnC(11)
C(31)SnC(21)
C(11)SnC(21)
C(31)SnC(31A)
126.2(2)
116.3(2)
C(32)C(33)C(34) 114.8(17)
Z
C(3)C(2)C(7)
116.9(2)
124.5(2)
118.4(2)
123.9(3)
118.8(2)
117.3(3)
122.8(3)
116.7(3)
115.2(3)
119.9(3)
ρ
calcd, mg m–3
Absorption coefficient, mm–1
F(000)
1.413
117.30(11) C(3)C(2)C(1)
1.086
9.4(3)
C(7)C(2)C(1)
O(3)NO(4)
O(3)NC(3)
1064
C(11)SnC(31A) 116.7(2)
C(21)SnC(31A) 125.6(2)
Crystal size, mm
0.40 × 0.25 × 0.18
3.26 to 27.48
θ range for data collection, deg
Index ranges
C(31)SnO(2)
C(31)SnO(1)
C(11)SnO(1)
C(21)SnO(1)
C(31A)SnO(1)
O(2)SnO(1)
85.32(19) O(4)NC(3)
84.74(19) C(4)C(3)C(2)
90.63(9) C(4)C(3)N
89.70(9) O(6)C(6)C(5)
84.31(18) C(7)C(6)C(5)
–13 ≤ h ≤ 12
–24 ≤ k ≤ 24
–15 ≤ l ≤ 1
30439
5535 (Rint = 0.0670)
4297
Reflections collected
Independent reflections
Reflections observed (I > 2σ(I))
Data completeness
170.02(6) C(6)O(6)C(61) 117.5(2)
111.2(6) C(6)C(7)C(2) 121.6(3)
C(32)C(31)Sn
0.997
C(33)C(32)C(31) 114.3(12)
Absorption correction
Semiempirical from
equivalents
Max. and min. transmission
Refinement method
0.8285 and 0.6705
plex II is 0.079. This value indicates a slighly distorted
trigonal-bipyramidal arrangement around the Sn atom.
The angles of axial bonds (OSnO) are 170.02°, while
the sum of the equatorial CSnC angles is 359.8°. The bond
lengths are in agreement with the reported triorganotin(IV)
Full-matrix least-squares
on F2
Refined parameters
Goodness-of-fit on F2
291
1.044
carboxylates [32]. The intermolecular C=O
Sn coor-
Final R indices (I > 2σ(I))
R1 = 0.0330
wR2 = 0.0676
dination in compound II leads to infinite zigzag chains
containing the Sn centers and carboxylate groups. The
crystal data for II are listed in Table 7, selected bond
lengths and bond angles are given in Table 8. There is
disorder at the α-carbon of one butyl group (C(31) and
C(31A)) in 1 : 1. Due to their close special proximity,
they have only been refined isotropically. The refined
structure is given in Fig. 2.
R indices (all data)
R1 = 0.0531
wR2 = 0.0748
onal-bipyramidal coordination, the equatorial plane
being defined by three R groups, while axial positions
are occupied by two oxygen atoms. According to liter-
ature [31], the geometry around Sn atom can be charac-
terized by τ = (β – α)/60, where β is the largest of the
basal angles around the Sn atom. The angle values α =
β = 180° correspond to a square-pyramidal geometry,
and the value α = 120° corresponds to a perfect trigo-
nal-bipyramidal geometry. Thus, the x value is equal to
zero for a perfect square-pyramidal and one for perfect
The atomic coordinates and other parameters of
compound II have been deposited with the Cambridge
Crystallographic Data Center (no. 699389; deposit@
ccdc. cam.ac.uk).
Thus, 4,5-dimethoxy-2-nitrobenzoic acid in the
reaction with organotin oxides/halides yields the orga-
notin carboxylates in anhydrous toluene, which have
trigonal-bipyramidal. The calculated τ value for com- been characterized by various analytical and spectro-
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 35 No. 12 2009

902
SHAH et al.
14. Shahzadi, S., Shahid, K., Ali, S., and Ahmed, B., Turk.
J. Chem., 2008, vol. 32, p. 333.
15. Sadiq-ur-Rehman, Ali, S., and Shahzadi, S., Heteroat.
Chem., 2008, vol. 19, no. 6, p. 612.
scopic techniques. The resulting triorganotin carboxy-
lates are one-dimensional polymer as solid with trigo-
nal bipyramidal geometry, while in solution, they are
tetrahedral. Diorganotin carboxylates are octahedral in
the solid phase, while in non-coordinating solvent the
coordination number is between 5 and 6. Biological
16. Shahid, K., Shahzadi, S., and Ali, S., Serb. J. Chem.,
2009, vol. 74, no. 2, p. 141.
activity data show that all complexes exhibit the signif- 17. Armarego, W.L.F. and Chai, C.L.L., Purification of Lab-
oratory Chemicals, London-New York: Butterworth-
icant activity with few exceptions.
Heinemann, 2003.
18. Bhatti, M.H., Ali, S., Masood, H., et al., Synth. React.
Inorg. Met-Org. Chem., 2000, vol. 30, p. 1715.
ACKNOWLEDGMENTS
19. Ahmad, F., Ali, S., Pervaz, M., et al., Heteroat. Chem.,
S. Ali is thankful to the Quaid-i-Azam University
(Islamabad, Pakistan) for financial support.
2002, vol. 13, p. 638.
20. Kalinowski, H.O., Berger, S., and Brown, S., 13C NMR
Spectroskopie, Stuttgart (Germany): Thieme, 1984.
REFERENCES
21. Holecˇek, J. and Lycka, A., Inorg. Chim. Acta, 1986,
1. Shahzadi, S. andAli, S., J. Iran Chem. Soc., 2008, vol. 5,
vol. 118, p. L15.
p. 16.
22. Ahmad, F., Ali, S., Parvez, M., et al., Heteroat. Chem.,
2. Belwal, S., Joshi, S.C., and Singh, R.V., Main Group
Met. Chem., 1997, vol. 20, p. 313.
3. Patricolo, E., Mansueto, C., D’Agati, P., and Pel-
lerito, L., Appl. Organomet. Chem., 2001, vol. 15,
p. 916.
2002, vol. 13, p. 638.
23. Danish, M., Ali, S., Badshah, A., et al., Synth. React.
Inorg. Met-Org. Chem., 1997, vol. 27, p. 863.
24. Wrackmeyer, B., Kehr, G., and Süβ, J., Chem. Ber.,
1993, vol. 126, p. 2221.
4. Puccia, E. and Mansueto, C., Cangialosi, M,V., et al.,
25. Davis, A.G. and Smith, P.J., In: Comprehensive Organome-
tallic Chemistry, Wilkinson, G., Stone, F.G.A., and
Abel, E.W. Eds., Oxford: Pergamon Press, 1982, vol. 519,
p. 2.
Appl. Organomet. Chem., 2001, vol. 15, p. 213.
5. Molloy, K.C., Quill, K., and Nowell, I.W., Dalton Trans.,
1986, vol. 5, p. 85.
6. Zubita, J.A. and Zuckerman, J.J., Inorg. Chem., 1987,
26. Saraswati, B.S. and Mason, J., Polyhedron, 1986, vol. 5,
vol. 24, p. 251.
p. 1449.
7. Shahid, K., Ali, S., Shahzadi, S., et al., Synth. React.
Inorg. Met.-Org. Chem., 2003, vol. 33, p. 1221.
27. Danish, M., Alt, H.G., Badshah, A., et al., J. Organomet.
Chem., 1995, vol. 486, p. 51.
8. Ahmed, S., Ali, S., Ahmed, F., et al., Synth. React. Inorg.
Met.-Org. Chem., 2002, vol. 32, p. 1521.
28. Rahman, A., Chaudhary, M.I., and Thomson, W.J., Bio-
assay Techniques for Drug Development, Amsterdam:
Harward Academic, 2001, p. 14.
9. Danish, M., Ali, S., Shahid, K., and Mazhar, M.,
J. Chem. Soc. Pak., 2004, vol. 26, p. 140.
29. Molloy, K.C., The Chemistry of Metal Carbon Bond,
Hartley, F.E., Ed., New York: Wiley, 1989, vol. 5.
10. Rehman, W., Badshah, A., Baloch, M.K., et al., J. Chin.
Chem. Soc., 2004, vol. 51, p. 929.
11. Rose, M.S., J. Biochem., 1969, vol. 111, p. 129.
30. Camacho, C.C. de Vos, D., et al., Main Group Met.
Chem., 2000, vol. 23, p. 381.
31. Addison, A.W., Nageswara, R.T., Reedijk, J., et al., Dal-
ton Trans., 1984, p. 1349.
12. Rose, M.S. and Lock, E.A., J. Biochem., 1970, vol. 120,
p. 151.
13. Blunden, S.J., Smith, P.J., and Sugavanaman, B., Pestic. 32. Ma, C.L., Zhang, Q.F., Zhang, R.F., and Qiu, L.L.,
Sci., 1984, vol. 15, p. 253.
J. Organomet. Chem., 2005, vol. 690, p. 3033.
RUSSIAN JOURNAL OF COORDINATION CHEMISTRY Vol. 35 No. 12 2009