Antimony(III) and bismuth(III) complexes containing O- and N-chelating ligands: Synthesis, FT-IR, 1H and 13C NMR spectroscopic and mass spectrometric studies

Article abstract of DOI:10.1515/mgmc-2017-0008

Reaction of SbCl₃ with sodium salt of vanillinidene-2-methylaminobenzene (vmabH) and salicylidene-3-nitroaminobenzene (snabH) in 1:1 and 1:2 molar ratios afforded complexes of the type [Sb(η²-sb)_nCl_3-n ](1-4) [w

Full text of DOI:10.1515/mgmc-2017-0008

Main Group Met. Chem. 2017; aop
Ajeet Kumar Kushwaha, Meenakshi, Nitesh Jaiswal, Avadhesh Pratap Singh
and Raj Kumar Dubey*
Antimony(III) and bismuth(III) complexes
containing O- and N-chelating ligands: synthesis,
FT-IR, 1H and 13C NMR spectroscopic and mass
spectrometric studies
DOI 10.1515/mgmc-2017-0008
(Khan et al., 2011), anthelminthic (Newlove et al., 2011),
antitrypanosomal (Parrilha et al., 2012), antimicrobial
(Kasuga et al., 2006), and anticancer (Ozturk et al., 2012)
agents. Furthermore, antimony complexes have shown
prominent application in catalysis (Ning et al., 2016).
Bismuth(III) complexes are well acknowledged for their
role in organic synthesis (Bothwell et al., 2011), nano
material synthesis (Stavila et al., 2009), medicine (Briand
and Burford, 1999), and biocoordination (Yang and Sun,
2007). Recently Bi(III) Schiff base complexes demon-
strated strong inhibitory action against microbes (Li et al.,
2015) and as antibiotics against Helicobacter pylori
(Andrews et al., 2014; Pathak et al., 2015). Taking above
facts in view, our interest in main group metal complexes
(Dubey et al. 2011b, 2013, 2014) prompts us to synthe-
size antimony and bismuth complexes with biologically
potent ligands such as 2-(o-hydroxyphenyl)-benzothia-
zole (HPBT) (Singh et al. 2014), which also is known for its
Received February 14, 2017; accepted March 20, 2017
Abstract: Reaction of SbCl3 with sodium salt of vanillin-
idene-2-methylaminobenzene (vmabH) and salicylidene-
3-nitroaminobenzene (snabH) in 1:1 and 1:2 molar ratios
afforded complexes of the type [Sb(η2-sb)nCl3−n](1–4) [where
sbꢀ=ꢀvanillinidene-2-methyl-1-aminobenzene (vmabH) (1, 2)
and salicylidene-3-nitroaminobenzene (snabH) (3, 4)]. Bis-
muth complexes of type [Bi(PBT)nCl3−n] (5, 6) have been syn-
thesized similarly by the reaction of BiCl3 with sodium salt
of 2-(o-hydroxyphenyl)-benzothiazole (HPBT) in different
molar ratios (where nꢀ=ꢀ1−2). These newly synthesized com-
plexes of antimony and bismuth have been characterized
by elemental (C, H, N, S, Sb, and Bi) analysis and spectro-
scopic IR, 1H NMR, and 13C NMR techniques. The molecular
composition of three selective complexes has been con-
firmed by mass spectrometric studies.
Keywords: antimony(III) complexes; bismuth(III) com- electroluminescent properties (Yu et al., 2003) and Schiff
plexes; 2-(o-hydroxyphenyl)-benzothiazole (HPBT).
bases (Dubey et al. 2011a, 2012, 2014) derived by conden-
sation of o-vanillin, salicylaldehyde with o-toluidine,
m-nitroaniline, respectively.
Introduction
Antimony and bismuth complexes derived from Schiff Results and discussion
bases are given considerable importance due to their sig-
nificant biological properties which lead to therapeutic The antimony(III) complexes 1–4 have been prepared
effect (Tiekink, 2002; Ge and Sun, 2007). Antimony com- by the reaction of antimony trichloride with sodium salt
plexes have shown significant potential against tumor cell of vanillinidene-2-methylaminobenzene (vmabH) and
(Hadjikakou et al., 2015) and are used as antileishmanial salicylidene-3-nitroaminobenzene (snabH) in 1:1 and 1:2
ratios as shown in Scheme 1. Bismuth(III) complexes have
been synthesized by the reaction of bismuth trichloride
with sodium salt of 2-(o-hydroxyphenyl)-benzothiazole
(HPBT) in different molar ratios as shown in Scheme 2.
Antimony complexes are dark yellow to brown colored
solids, whereas bismuth complexes are creamy white
solid. These complexes are insoluble in organic solvents
and soluble in polar solvents. Some physical properties of
these complexes are summarized in Table 1.
*Corresponding author: Raj Kumar Dubey, Synthetic Inorganic and
Metallo-Organic Research Laboratory, Department of Chemistry,
University of Allahabad, Allahabad 211002, India,
e-mail: rajalkoxy@yahoo.com
Ajeet Kumar Kushwaha, Meenakshi, Nitesh Jaiswal and Avadhesh
Pratap Singh: Synthetic Inorganic and Metallo-Organic Research
Laboratory, Department of Chemistry, University of Allahabad,
Allahabad 211002, India
Brought to you by | UCL - University College London
Authenticated
Download Date | 4/20/17 9:09 AM

ꢁꢁꢁꢂ
2ꢀ
ꢀA.K. Kushwaha et al.: Antimony(III) and bismuth(III) complexes
H
S
O
NH2
C
N
X
Y
Z
OH
OH
MeOH
stirr ∼2 h
MeOH
reflux ~6 h
Na
S
H
C
N
N
NaO
Z
OH
X
Y
C6H6
reflux ~12 h
BiCl3
MeOH
reflux ∼6 h
-NaCl
-2NaCl
Na
S
H
C
O
N
N
S
N
Bi
O
S
N
Z
ONa
X
Y
O
Bi
Cl
Cl
Cl
C6H6
reflux ~12 h
SbCl3
5
Scheme 2:ꢁGeneral method for the preparation of bismuth(III)
complexes.
y
(Viswanathamurthi et al., 2000), which was further sup-
ported by shift of v(C-O) band ~10–20 cm−1 higher frequency
region in complexes compared to free ligands in the region
1272–1295 cm−1 (Dubey and Singh, 2013) and appearance
of new bands in the regions 573–580 and 546–570 cm−1
for bismuth and antimony complexes, respectively (Dur-
gashanker and Singh, 2007). The involvement of azome-
thine nitrogen in bonding in complexes was supported
by shifting of νC=N towards lower frequency 1615–1598 cm−1
region compared to free ligands 1634–1616 cm−1 region
(Vajpayee and Singh, 2007) and appearance of new bands
in the region 580–540 cm−1 due to M←N stretching vibra-
tion (Dawara and Singh, 2011).
Y
x
z
z
x
x
H
Cl
H
N
O
N
N
O
Cl
Cl
Sb
Sb
O
H
Cl
y
2, 4
1, 3
Y
H
Z
OCH3
OCH3
H
Complex
X
CH3
CH3
H
1
2
3
4
H
NO2
NO2
H
H
1H NMR spectroscopy
Scheme 1:ꢁGeneral method for the preparation of Schiff bases and
antimony(III) complexes.
1
The H NMR spectra recorded in DMSO-d6 using tetra-
1
methylsilane as internal reference and H NMR data of
free ligands and their complexes 1–6 are collected in
1
IR spectroscopy
Table 3. A comparison of H NMR spectra of ligand with
metal complexes can lead to the following conclusions:
Salient absorption bands were observed in IR spectra for (i) 1H NMR spectra of complexes 1–6 exhibit no signal due
complexes 1–6 and free ligands, which are summarized to phenolic hydrogen (OH) observed at 13.20–12.76 ppm
in Table 2. The characteristic feature of the IR spectra in the ligands, indicating metallation of phenolic group
of the complexes is disappearance of phenolic stretch- (OH) (Dubey et al., 2014); (ii) shifting of azomethine
ing vibration v(O-H) observed in free ligands in the region hydrogen signal to a higher region 9.93–8.32 ppm com-
3564–3343 cm−1 due to deprotonation of phenolic hydrogen pared to parent Schiff bases (9.23–8.23 ppm) supporting
Brought to you by | UCL - University College London
Authenticated
Download Date | 4/20/17 9:09 AM

ꢂꢁꢁꢁ
A.K. Kushwaha et al.: Antimony(III) and bismuth(III) complexesꢀ
ꢀ3
Table 1:ꢁSynthetic and analytical details of antimony(III) and bismuth(III) complexes 1–6.
Complex
empirical formula
ꢁ
Mol. wt.ꢁ Physical
state
ꢁ
MPꢁ
(°C)
Yieldꢁ
%ꢁ
% Elemental analysis found (calcd)
Cꢁ
Hꢁ
Nꢁ
Sꢁ
Clꢁ
Sbꢁ
Bi
vmabH I
ꢃ
241.29ꢃ Orange
ꢃ
95ꢃ
140ꢃ
132ꢃ
105ꢃ
125ꢃ
148ꢃ
130ꢃ
165ꢃ
172ꢃ
78ꢃ
64ꢃ
60ꢃ
82ꢃ
69ꢃ
62ꢃ
–ꢃ
74.25ꢃ
(74.67)
41.13ꢃ
(41.61)
56.48ꢃ
(56.50)
64.12ꢃ
(64.46)
35.85ꢃ
(35.99)
48.75ꢃ
(48.82)
68.65ꢃ
(68.70)
30.75ꢃ
6.40ꢃ
(6.27)
3.11ꢃ
(3.26)
4.63ꢃ
(4.43)
4.29ꢃ
(4.16)
2.12ꢃ
(2.09)
2.55ꢃ
(2.84)
3.75ꢃ
(3.99)
1.49ꢃ
5.69ꢃ
(5.81)
3.85ꢃ
(3.24)
4.20ꢃ
(4.39)
11.23ꢃ
(11.56)
6.80ꢃ
(6.46)
8.75ꢃ
(8.76)
6.25ꢃ
(6.16)
2.71ꢃ
(2.77)
4.18ꢃ
(4.02)
–ꢃ
–ꢃ
–ꢃ
–
C15H15NO2
solid
[Sb(η2-vmab)Cl2]ꢀ1 ꢃ
C15H14Cl2NO2Sb
432.94ꢃ Dark yellowꢃ
–ꢃ
–ꢃ
–ꢃ
–ꢃ
–ꢃ
16.85ꢃ
(16.38)
5.55ꢃ
(5.56)
–ꢃ
27.95ꢃ
(28.12)
18.87ꢃ
(19.09)
–ꢃ
–
–
–
–
–
–
solid
[Sb(η2-vmab)2Cl]ꢀ2 ꢃ
C30H28ClN2O4Sb
637.77ꢃ Dark yellowꢃ
solid
snabH II
ꢃ
242.23ꢃ Yellow
ꢃ
ꢃ
ꢃ
C13H10N2O3
solid
[Sb(η2-snab)Cl2]ꢀ3 ꢃ
C13H9Cl2N2O3Sb
433.89ꢃ Brown
solid
16.20ꢃ
(16.34)
5.62ꢃ
(5.54)
–ꢃ
28.50ꢃ
(28.06)
19.10ꢃ
(19.04)
–ꢃ
[Sb(η2-snab)2Cl]ꢀ4 ꢃ
C26H18ClN4O6Sb
639.66ꢃ Brown
solid
HPBTꢀIII
C13H9NOS
[Bi(PBT)Cl2]ꢀ5
C13H8BiCl2NOS
[Bi(PBT)2Cl]ꢀ6
C26H16BiClN2O2S2
ꢃ
ꢃ
ꢃ
227.28ꢃ White solid ꢃ
14.00ꢃ
(14.11)
6.25ꢃ
(6.33)
9.45ꢃ
(9.20)
506.16ꢃ Creamy
white solid
696.98ꢃ Creamy
white solid
ꢃ
ꢃ
61ꢃ
59ꢃ
14.25ꢃ
(14.01)
5.19ꢃ
–ꢃ
–ꢃ
40.93
(41.29)
29.64
(30.82)
44.23ꢃ
(44.80)
(1.59)
2.20ꢃ
(2.31)
(5.09)
(29.98)
Table 2:ꢁCharacteristic IR frequencies (cm−1) of new antimony(III)
and bismuth(III) complexes 1–6.
coordination of azomethine nitrogen to metal atom
(Solanki et al., 2009).
Complex
ꢁ
v(OH) ꢁ v(Cꢂ=ꢂN) ꢁ v(C-O) Phenolic ꢁ v M←N ꢁ v(M-O)
13C NMR spectroscopy
vmabH
ꢃ
3564 ꢃ 1617
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
1272
ꢃ
–
ꢃ
–
[Sb(η2-vmab)Cl2]ꢀ1ꢃ
–
–
ꢃ 1608
ꢃ 1611
1282 ꢃ 438 ꢃ 570
1284 ꢃ 438 ꢃ 580
[Sb(η2-vmab)2Cl]ꢀ2ꢃ
The 13C NMR data of free ligands and their complexes
1–6 are summarized in Table 4. In the 13C NMR spectra of
the Schiff bases, signals in the region 149.71–156.53 ppm
due to azomethine carbon were shifted towards higher
snabH
ꢃ
3343 ꢃ 1614
1277
ꢃ
–
ꢃ
–
[Sb(η2-snab)Cl2]ꢀ3 ꢃ
–
–
ꢃ 1609
ꢃ 1607
1283 ꢃ 440 ꢃ 578
1286 ꢃ 439 ꢃ 546
[Sb(η2-snab)2Cl]ꢀ4 ꢃ
HPBT
ꢃ
ꢃ
ꢃ
3405 ꢃ 1640
1295
ꢃ
–
ꢃ
–
[Bi(PBT)Cl2]ꢀ5
[Bi(PBT)2Cl]ꢀ6
–
–
ꢃ 1622
ꢃ 1620
1315 ꢃ 455 ꢃ 573 value in the region 152.16–159.19 ppm in the complexes,
1314 ꢃ 455 ꢃ 580
indicating the involvement of azomethine nitrogen
Table 3:ꢁ1H NMR data (ppm) for new complexes 1–6.
Complex
ꢁ
HCꢂ=ꢂN
ꢁ
Ar-H
ꢁ
Ar-OH
ꢁ
-OCH3
ꢁ
-CH3
vmabH
ꢃ
8.50 (s, 1H)ꢃ
9.66 (s, 1H)ꢃ
9.79 (s, 2H)ꢃ
8.46 (s, 1H)ꢃ
9.76 (s, 1H)ꢃ
9.57 (s, 2H)ꢃ
8.23 (s, 1H)ꢃ
9.58 (s, 1H)ꢃ
9.65 (s, 2H)ꢃ
6.8–7.8 (m, 7H) ꢃ
7.8–8.0 (m, 7H) ꢃ
7.0–8.0 (m, 14H)ꢃ
6.6–7.9 (m, 8H) ꢃ
6.9–8.0 (m, 8H) ꢃ
6.9–7.9 (m, 16H)ꢃ
6.8–7.8 (m, 8H) ꢃ
7.0–8.3 (m, 8H) ꢃ
7.0–8.3 (m, 16H)ꢃ
13.20 (s, 1H)ꢃ
3.81 (s, 3H) ꢃ
3.89 (s, 3H) ꢃ
3.94 (s, 6H) ꢃ
2.38 (s, 3H)
2.40 (s, 3H)
2.40 (s, 6H)
–
–
–
–
–
–
[Sb(η2-vmab)Cl2]ꢀ1 ꢃ
–
–
ꢃ
ꢃ
[Sb(η2-vmab)2Cl]ꢀ2 ꢃ
snabH
ꢃ
12.67 (s, 1H)ꢃ
–
–
–
–
–
–
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
ꢃ
[Sb(η2-snab)Cl2]ꢀ3 ꢃ
–
–
ꢃ
ꢃ
[Sb(η2-snab)2Cl]ꢀ4 ꢃ
HPBT
[Bi(PBT)Cl2]ꢀ5
[Bi(PBT)2Cl]ꢀ6
ꢃ
ꢃ
ꢃ
11.74 (s, 1H)ꢃ
–
–
ꢃ
ꢃ
Brought to you by | UCL - University College London
Authenticated
Download Date | 4/20/17 9:09 AM

ꢁꢁꢁꢂ
ꢀA.K. Kushwaha et al.: Antimony(III) and bismuth(III) complexes
4ꢀ
Table 4:ꢁ13C NMR data (ppm) for new complexes of antimony(III) and bismuth(III) complexes.
Complex
C-O phenolic
HCꢂ=ꢂN
Ar-C
-OCH3
Ar-CH3
vambH
145.8 (s, 1C)
162.2 (s, 1C)
159.1 (s, 2C)
144.4 (s, 1C)
161.1 (s, 1C)
157.1 (s, 2C)
158.5 (s, 1C)
163.4 (s, 1C)
165.8 (s, 2C)
151.6 (s, 1C)
159.1 (s, 1C)
155.5 (s, 2C)
149.7 (s, 1C)
152.1 (s, 1C)
157.3 (s, 2C)
152.5 (s, 1C)
154.5 (s, 1C)
156.4 (s, 2C)
132.5–122.7 (s, 11C)
145.6–121.3 (s, 11C)
147.7–121.8 (s, 22C)
147.4–123.2 (s, 11C)
143.2–121.9 (s, 11C)
139.4–120.6 (s, 22C)
140.3–119.2 (s, 11C)
135.5–119.5 (s, 11C)
133.8–117.0 (s, 22C)
54.1 (s, 1C)
18.1 (s, 1C)
[Sb(η2-vmab)Cl2] 1
[Sb(η2-vmab)2Cl] 2
snabH
53.17 (s, 1C)
17.7 (s, 1C)
54.07 (s, 2C)
17.5 (s, 2C)
–
–
–
–
–
–
–
–
–
–
–
–
[Sb(η2-snab)Cl2] 3
[Sb(η2-snab)2Cl] 4
HPBT
[Bi(PBT)Cl2] 5
[Bi(PBT)2Cl] 6
method (Vogel, 2008) while antimony and bismuth were estimated
complexometrically and iodometrically, respectively (Vogel, 2008).
The Schiff bases were synthesized according to the literature method
(Dubey et al., 2005).
in bonding with antimony and bismuth atom (Dubey
et al., 2014). Signal due to phenolic carbon in the region
144.45–156.53 ppm shifted toward the higher value in the
region 157.19–165.81 ppm, indicating the involvement of
phenolic oxygen in the bonding (Dubey et al., 2011b).
Physical measurement
Elemental analyses for C, H, N, and S were carried out with Carlo
Erba 1108 element analyzer. Melting points were measured in open
tubes with a Stuart scientific apparatus and are uncorrected. Infra-
red spectra were recorded on a Perkin-Elmer 100 FT-IR spectropho-
Mass spectrometry
+
The TOF-MS ES spectra of the complexes 1, 5, and 6 were
−1
1
tometer in the range 4000–400 cm . H and 13C NMR spectra were
recorded on Bruker Avance II 400 NMR spectrometer in DMSO-d6 and
chemical shifts were given in ppm relative to Me4Si as internal ref-
erence. ESI-MS spectra were recorded on Agilent 6520 Q-Tof LC-MS,
MS/MS spectrometers in acetonitrile.
recorded. In the spectra of complexes 1, 5, and 6 molecu-
lar ion peak was observed at m/z 432.45 [(C15H14Cl2NO2Sb);
calculated massꢀ=ꢀ430.94], 507.39 [(C13H8BiCl2NOS); calcu-
lated massꢀ=ꢀ504.95] and 697.19 [(C26H16BiClN2O2S2); calcu-
lated massꢀ=ꢀ696.01], respectively, which correspond to the
monomeric molecular composition of the complexes.
Synthesis of complexes
Similar procedure was used for the preparation of the complexes
(1–6); therefore, for the sake of brevity, general preparative details are
given below for complex 1. To a benzene (~20 mL) solution of SbCl3
(1.140 g, 4.99 mmol) sodium salt of Schiff base [prepared by dissolving
equimolar amount of sodium metal (0.114 g, 4.99 mmol) and a Schiff
Conclusion
Synthesis of antimony(III) and bismuth(III) complexes
have been achieved by the reactions of SbCl3 and BiCl3
with appropriate sodium salt of ligands in 1:1 and 1:2 molar base, vanillinidene-2-methylaminobenzene (1.205 g, 4.99 mmol) in
MeOH (~30 mL)] was added dropwise in 1:1 molar ratio with constant
ratios, respectively. Spectroscopic studies confirm the
stirring. The reaction mixture was allowed to reflux for ~12 h. The pre-
O- and N-atom involvment in the bonding and molecular
cipitated NaCl was removed by filtration. The solvent was removed
composition of complexes was proved by the mass spec-
by distillation. The solid products were dried under reduced pressure
trometric studies.
and recrystallized from the mixture of THF- n–hexane in 1:4.
Acknowledgments: The authors are thankful to UGC, New
Delhi for doctoral fellowship. Authors gratefully acknowl-
edge the SAIF Chandigarh for spectroscopic and mass
analysis and CDRI Lucknow for elemental analysis.
Experimental
Materials
SbCl3 (Merck, Germany), BiCl3, (o-hydroxyphenyl) benzothiazole
(Sigma Aldrich, Bangalore, India), o-vanillin (Alfa-aesar), o-toluidine
(LOBA, Mumbai, India), m-nitroaniline, and salicylaldehyde (CDH,
New Delhi, India) were used without further purification. All solvents
References
used were of reagent grade and purified by standard procedures Andrews, P. C.; Blair, V. L.; Ferrero, R. L.; Junk, P. C.; Kedzierski, L.;
(Armarego and Perrin, 1997). Chlorine was estimated by Volhard’s
Peiris, R. M. Bismuth(III) β-thioxoketonates as antibiotics
Brought to you by | UCL - University College London
Authenticated
Download Date | 4/20/17 9:09 AM

ꢂꢁꢁꢁ
A.K. Kushwaha et al.: Antimony(III) and bismuth(III) complexesꢀ
ꢀ5
against Helicobacter pylori and as anti-leishmanial agents.
Dalton Trans. 2014, 43, 1279.
Armarego, W. L. F.; Perrin, D. D. Purification of laboratory chemicals,
4th Edition; Butterworth-Heinemann: Oxford, 1997.
Bothwell J. M.; Krabbez, S. W.; Mohan, R. S. Applications of
bismuth(III) complexes in organic synthesis. Chem. Soc. Rev.
2011, 40, 4649–4707.
Briand, G. G.; Burford, N. Bismuth complexes and preparations
with biological or medicinal relevance. Chem. Rev. 1999, 99,
2601–2657.
Li, C-H; Jiang, J-H.; Li, X.; Tao, L-M.; Xiao, S. X.; Hui, H. W.; Zhang, H.;
Jiang, C.; Xie, J-Q.; Peng, M. N.; et al. Synthesis, crystal structure
and biological properties of a bismuth(III) Schiff-base complex.
RSC Adv. 2015, 5, 94267–94275.
Newlove, T.; Guimarães, L. H.; Morgan, D. J.; Alcântara, L.; Glesby,
L.; Carvalho, E. M.; Machado, P. R. Antihelminthic therapy and
antimony in cutaneous leishmaniasis: a randomized, double-
blind, placebo-controlled trial in patients co-infected with
helminthes and Leishmaniabraziliensis. Am. J. Trop. Med. Hyg.
2011, 84, 551–555.
Dawara, L.; Singh, R. V. Microwave-assisted synthesis, characteri-
zation, antimicrobial, and pesticidal activity of bismuth and
antimony complexes with coumarin-based ligands. J. Coord.
Chem. 2011, 64, 931–941.
Dubey, R. K.; Mishra, A. N.; Mishra, C. M. Synthesis, reactivity and
physico-chemical studies of some novel mixed ligand complexes
of copper(II). Indian J. Chem. 2005, 44, 1159–1164.
Dubey, R. K.; Dubey, U. K.; Mishra, S. K. Synthesis, spectroscopic
Ning, X.; Li, Y.; Yu, H.; Peng, F.; Wang, H.; Yang, Y. Promoting role of
bismuth and antimony on Pt catalysts for the selective oxidation
of glycerol to dihydroxyacetone. J. Catal. 2016, 335, 95–104.
Ozturk, I. I.; Banti, C. N.; Manos, M. J.; Tasiopoulos, A. J.; Kourk-
oumelis, N.; Charalabopoulos, K.; Hadjikakou, S. K. Synthesis,
characterization and biological studies of new antimony(III)
halide complexes with ω-thiocaprolactam. J. Inorg. Biochem.
2012, 109, 57–65.
(IR, electronic, FAB-mass and PXRD), magnetic and antimicrobial Parrilha, G. L.; Dias, R. P.; Rocha, W. R.; Mendes, I. C.; Benítez, D.;
studies of new iron(III) complexes containing Schiff bases and
substituted benzoxazole ligands. J. Coord. Chem. 2011a, 64,
2292–2301.
Varela, J.; Cerecetto, H.; González, H.; Melo, C. M. L.; Neves, J.
K. A. L.; et al. 2-Acetylpyridine and 2-benzoylpyridine-derived
thiosemicarbazones and their antimony(III) complexes exhibit
high anti-trypanosomal activity. Polyhedron 2012, 31, 614–621.
Pathak, A.; Blair, V. L.; Ferrero, R. L.; Junk, P. C.; Tabora R. F.;
Andrews, P. C. Synthesis and structural characterisation of
bismuth(III) hydroxamates and their activity against Helicobac-
ter pylori. Dalton Trans. 2015, 44, 16903.
Singh, M.; Singh, S. K.; Gangwar, M.; Nath, G.; Singh, S. K. Design,
synthesis and mode of action of some benzothiazole derivatives
bearing an amide moiety as antibacterial agents. RSC Adv. 2014,
4, 19013–19023.
Solanki, J. S.; Tripathi, U. N.; Bhardwaj, A.; Jena, V. K.
Synthesis, spectral studies, and antimicrobial evaluation of
antimony(III) tri[3(2′- hydroxyphenyl)-5-(4-substituted aryl]
pyrazolinate. Phosphorus, Sulfur Silicon Relat. Elem. 2009, 184,
2169–2178.
Dubey, R. K.; Singh, A. P.; Dwivedi, N. Synthesis and physicochemi-
cal characterization of some hexacoordinated tin(IV) Schiff base
complexes. Main Group Met. Chem. 2011b, 34, 77–83.
Dubey, R. K.; Baranwal, P.; Jha, A. K. Zinc(II) and mercury(II) com-
plexes with Schiff bases: syntheses, spectral, and structural
characterization. J. Coord. Chem. 2012, 65, 2645–2656.
Dubey, R. K.; Singh, A. P. Dimeric and monomeric six-coordinate
tin(IV) complexes: synthesis and spectral (IR, NMR (1H, 13C,
119Sn), TOF-MS, and ESI-MS) studies. J. Coord. Chem. 2013, 66,
2201–2207.
Dubey, R. K.; Singh, A. P.; Patil, S. A. Synthesis, spectroscopic
characterization and DNA cleavage studies of dibutyltin(IV)
complexes of bidentate Schiff bases. Inorg. Chim. Acta 2014,
410, 39–45.
Durgashanker; Singh Y. Studies on homo- and hetero- dinuclear
derivatives of antimony(III) containing Schiff base ligands.
Phosphorus, Sulfur, Silicon Relat. Elem. 2007, 182, 1805–1817.
Ge, R.; Sun, H. Bioinorganic chemistry of bismuth and antimony:
target sites of metallodrugs. Acc. Chem. Res. 2007, 40,
267–274.
Hadjikakou, S. K.; Ozturk, I. I.; Banti, C. N.; Kourkoumelis, N.;
Hadjiliadis N. Recent advances on antimony(III/V) complexes
with potential activity against tumor cells. J. Inorg. Biochem.
2015, 153, 293–305.
Kasuga, N.C.; Onodera, K.; Nakano, S.; Hayashi, K.; Nomiya, K. Syn-
theses, crystal structures and antimicrobial activities of 6-coor-
dinate antimony(III) complexes with tridentate 2-acetylpyridine
thiosemicarbazone, bis(thiosemicarbazone) and semicarbazone
ligands. J. Inorg. Biochem. 2006, 100, 1176–1186.
Khan, M. I.; Gul, S.; Hussain, I.; Khan, M. A.; Ashfaq, M.; Rahman,
I. U.; Ullah, F.; Durrani, G. F.; Baloch, I. B.; Naz, R. In vitro anti-
leishmanial and anti-fungal effects of new Sb III carboxylates.
Org. Med. Chem. Lett. 2011, 1, 1–7.
Stavila, V.; Whitmire, K. H.; Rusakova, I. Synthesis of Bi2S3 nano-
structures from bismuth(III) thiourea and thiosemicarbazide
complexes. Chem. Mater. 2009, 21, 5456–5465.
Tiekink, E. R. T. Antimony and bismuth complexes in oncology. Crit.
Rev. Oncol./Hematol. 2002, 42, 217–224.
Vajpayee, V.; Singh, Y. Some homo- and hetero-dinuclear complexes
of antimony(III) derived from Schiff base ligands. Phosphorus,
Sulfur, Silicon Relat. Elem. 2007, 182, 2565–2577.
Viswanathamurthi, P.; Dharmaraj, N.; Natarajan, K. Ruthenium(III)
complexes containing monofunctional bidentate Schiff bases.
Synth. React. Inorg. Met.-Org. Chem. 2000, 30, 1273–1285.
Vogel, A. I. A Textbook of Quantitative Chemical Analysis, 6th Edi-
tion; Longman Group: UK, 2008.
Yang, N.; Sun, H. Biocoordination chemistry of bismuth: recent
advances. Coord. Chem. Rev. 2007, 251, 2354–2366.
Yu, G.; Yin, S.; Liu, Y.; Shuai, Z.; Zhu, D. Structures, electronic states,
and electroluminescent properties of a zinc(II) 2-(2-hydroxy-
phenyl)- benzothiazolate complex. J. Am. Chem. Soc. 2003, 125,
14816–14824.
Brought to you by | UCL - University College London
Authenticated
Download Date | 4/20/17 9:09 AM