Mixed bis(morpholine-4-dithiocarbamato-S,S)antimony(III) complexes: Synthesis, characterization and biological studies

Article abstract of DOI:10.1002/aoc.3169

Some mixed bis(morpholine-4-dithiocarbamato-S,S)antimony(III) complexes [(OC₄H₈NCS₂)₂SbL] with oxygen or sulfur donor ligands [L = -OOCCH₃ (1), -OOCC₆H₅ (2), -SOCCH₃ (3), -SCH₂COOH (4), -OOCC₆H ₄(OH) (5), -SCH₂CH₂CH₃ (6), -OC ₆H₅ (7), SCH₂CH₂S- (8)] have been synthesized by reacting the chloro-bis(morpholine-4-dithiocarbamato-S,S) antimony(III) with corresponding oxygen or sulfur donor ligands in 1:1 or 2:1 stoichiometries. These have been characterized by melting point, molecular weight determination (cryoscopically), antimony (iodometrically) and sulfur (gravimetrically) estimation, elemental analyses (C, H and N), UV-visible, FT-IR, far IR, multinuclear NMR (¹H and ¹³C)], TG/DTA analysis, ESI-mass and powder X-ray diffraction studies. The splitting of the strong band observed at 1046-1066 cm^-1 due to (C-S) indicated anisobidentate mode of binding of the dithiocarbamate group, which was further supported by a ¹³C NMR signal appearing at around δ 200 due to NCS₂ moiety. The base peak observed at m/z 444.9 supports the strong chelating nature of the morpholine-4-dithiocarbamate compared to the other hetero ligands used. TGA revealed that, complexes 21 and 4 were decomposed in three steps; also 6 was decomposed in two steps, followed by the formation of Sb₂S₃. The results obtained by antimicrobial screening tests indicate that complex 3 showed a maximum zone of inhibition (20 mm) against Trichoderma ressie at a concentration of 200 μg ml^-1. Complexes 2, 3 and 8 are most active (zone of inhibition (ZI) 17-20 mm) against both of the fungal species Aspergillus niger and Trichoderma ressie as well as complex 4 (ZI 17 mm) and 6 (ZI 18 mm) against Trichoderma ressie. Copyright

Full text of DOI:10.1002/aoc.3169

Full Paper
Received: 16 March 2014
Revised: 26 April 2014
Accepted: 27 April 2014
Published online in Wiley Online Library: 20 June 2014
(wileyonlinelibrary.com) DOI 10.1002/aoc.3169
Mixed bis(morpholine-4-dithiocarbamato-S,S′)
antimony(III) complexes: synthesis,
characterization and biological studies
H. P. S. Chauhan*, Jaswant Carpenter and Sapana Joshi
Some mixed bis(morpholine-4-dithiocarbamato-S,S′)antimony(III) complexes [(OC4H8NCS2)2SbL] with oxygen or sulfur donor
ligands [L = ―OOCCH3 (1), ―OOCC6H5 (2), ―SOCCH3 (3), ―SCH2COOH (4), ―OOCC6H4(OH) (5), ―SCH2CH2CH3 (6), ―OC6H5 (7),
½ ―SCH2CH2S― (8)] have been synthesized by reacting the chloro-bis(morpholine-4-dithiocarbamato-S,S′)antimony(III) with cor-
responding oxygen or sulfur donor ligands in 1:1 or 2:1 stoichiometries. These have been characterized by melting point, molec-
ular weight determination (cryoscopically), antimony (iodometrically) and sulfur (gravimetrically) estimation, elemental analyses
(C, H and N), UV–visible, FT-IR, far IR, multinuclear NMR (1H and 13C)], TG/DTA analysis, ESI–mass and powder X-ray diffraction
studies. The splitting of the strong band observed at 1046–1066 cmꢀ1 due to υ(C―S) indicated anisobidentate mode of binding
of the dithiocarbamate group, which was further supported by a 13C NMR signal appearing at around δ 200 due to NCS2 moiety.
The base peak observed at m/z 444.9 supports the strong chelating nature of the morpholine-4-dithiocarbamate compared to the
other hetero ligands used. TGA revealed that, complexes 21 and 4 were decomposed in three steps; also 6 was decomposed in two
steps, followed by the formation of Sb2S3. The results obtained by antimicrobial screening tests indicate that complex 3 showed a
maximum zone of inhibition (20 mm) against Trichoderma ressie at a concentration of 200 μg mlꢀ1. Complexes 2, 3 and 8 are most
active (zone of inhibition (ZI) 17–20 mm) against both of the fungal species Aspergillus niger and Trichoderma ressie as well as com-
plex 4 (ZI 17 mm) and 6 (ZI 18 mm) against Trichoderma ressie. Copyright © 2014 John Wiley & Sons, Ltd.
Additional supporting information may be found in the online version of this article at the publisher’s web-site.
Keywords: antimony sulfide; dithiocarbamate; TG/DTA; powder XRD; antimicrobial
their characterization by spectral techniques. The complexes
upon thermal decomposition in inert nitrogen atmosphere give
Introduction
Complexes with a metal–sulfur bond have attracted considerable
attention during the last few decades owing to their interesting
coordination chemistry,[1a–d] spectral and theoretical features[2a–d]
and their biological activities.[3a–c] Among the sulfur donor ligands,
the dithiocarbamates (DTCs) have been used extensively by
synthetic and medicinal chemists because of their interesting
structural chemistry (strong chelation nature) and diverse pharma-
cological properties such as bactericidal,[4a–d] fungicidal,[5a–c]
anthelmintic,[6a,b] herbicidal,[7] antifouling,[8] algicidal,[9] growth-
depressant,[10] antioxidant,[11] antiparkinson,[12] anti-radiation[13]
and anticancer activities.[14a–c] In addition, they have been used in
polymer photo stabilizers,[15] precursors for creating sulfide film
semiconductors,[16] vulcanization processes,[17a,b] combinatorial
synthesis,[18] nitrogen–oxygen trapping agents[19] and a recently
developed application in ionic liquid synthesis.[20]
antimony sulfide (Sb2S3) as the last degradation product. Anti-
mony sulfide is a semiconducting material which has a band
gap between 1.78 and 2.5 eV and covers the maximum scan of
the visible and near-infrared range of the solar spectrum.[28a–c]
This material deals with the diverse area of commercial applications
as solar cells,[29] microwave devices,[30] television cameras,[31] ther-
moelectric and switching devices.[32,33] Hence it is noteworthy that
such complexes may be used commercially as a single-source pre-
cursor for creating sulfide film semiconductors.
The complexes have also been investigated for their
antimicrobial activities toward four bacteria, namely Bacillus subtilis,
Staphylococcus aureus, Pseudomonas aeruguinosa and Escherichia
coli, and two fungi: Trichoderma ressie and Aspergillus niger. From
the antimicrobial screening test, all synthesized complexes were
found to exhibit equal or greater potential results as antimicrobial
agents than the standard drugs: chloramphenicol and terbinafine.
Thus these promising results open new avenues for further
investigation and exploration of the antimicrobial activities of
such complexes.
Antimony(III) dithiocarbamate complexes have been studied
extensively[21] because of their wide range of applications such as
multifunctional additives to lubricants,[22] industrial processes,[23]
etc. Apart from dithiocarbamates, other interesting families of
ligands are carboxylates[24a,b,25a] and thiocarboxylates.[25a,b] The
synthesis and structural characterization of antimony(III) dithiocarbamato
complexes with carboxylic or thiocarboxylic group-containing
ligands have been reported recently in our laboratory.[26]
*
Correspondence to: H. P. S. Chauhan, School of Chemical Sciences, Devi Ahilya
University, Takshashila Campus, Khandwa Road, Indore 452001, India. E-mail:
hpsc@rediffmail.com
In continuation of our studies,[26,27a–d] we report herein the
synthesis of mixed bis(morpholine-4-dithiocarbamato-S,S′)anti-
mony(III) complexes with oxygen or sulfur donor ligands and
School of Chemical Sciences, Devi Ahilya University, Takshashila Campus,
Indore 452001, India
Appl. Organometal. Chem. 2014, 28, 605–613
Copyright © 2014 John Wiley & Sons, Ltd.

H. P. S. Chauhan et al.
Experimental
Material and Analytical Methods
All syntheses [except tris(morpholine-4-dithiocarbamato-S,S’)-
antimony(III)] were performed under moisture-free conditions.
SbCl3 (E. Merck) was distilled (85°C/ 0.7 mmHg) before use.
Ligands
– sodium acetate, sodium benzoate, potassium
thioacetate, sodium thioglycolate, sodium salicylate, sodium
1-propanethiolate, thiophenol and ethane-1,2-dithiol (all Aldrich
and E. Merck) – were used without further purification.
Solvents were purified by standard methods.[34] Potassium
morpholinyldithiocarbamate, tris(morpholine-4-dithiocarbamato-
S,S)antimony(III) and chloro-bis(morpholine-4-dithiocarbamato-S,S)
antimony(III) were prepared by the method reported in the litera-
ture with some modifications.[35,36]
Antimony was estimated iodometrically and sulfur was
estimated gravimetrically as barium sulfate.[37] Melting point
apparatus (B10 Tech India) was used to determine the melting
point of the complexes and are uncorrected. The cryoscopic
method was used to determine the molecular weights using
benzene solution. Multinuclear NMR (1H at 400 MHz and 13C
at 100 MHz) spectra were recorded on a Bruker Avance-III
FT-NMR spectrometer in CDCl3 solution using TMS as an internal
standard. Infrared spectra were recorded on a Bruker Tensor
27 FT-IR instrument in the range 4000–400 cmꢀ1 as KBr pellets,
and far-IR spectra were recorded as a Nujol mull over CsI
disks using a Megna-IR 550 spectrophotometer in the range
600–50 cmꢀ1. ESI mass spectra were recorded with a Waters
Micromass Q-ToF micro mass spectrometer and TGA was
performed using a Mettler Toledo instrument (model TGA/SDTA
851e). Powder X-ray diffraction (XRD) studies were performed on
a diffractometer system (XPERT-PRO) using Cu-Kα radiation at a
wavelength of 1.54 Å.
Scheme 2. Synthesis of (a) tris(morpholine-4-dithiocarbamato-S,S′)anti-
mony(III) and (b) chloro-bis(morpholine-4-dithiocarbamato-S,S′)antimony(III).
Synthesis of chloro-bis(morpholine-4-dithiocarbamato-S,S′)antimony(III)
A hexane solution (~15 ml) of SbCl3 (0.96 g; 4.2 mmol) was added
to the hexane solution (~30 ml) of antimony(III) tris(morpholine-
4-dithiocarbamato-S,S′) (5.12 g; 8.4 mmol) and refluxed for ~4 h.
The solvent was removed under vacuum to obtain the product
(Scheme 2b).
Synthesis of Compounds 1–7 in 1:1 Molar Ratio
Complex
1 was prepared by the addition of chloro-bis
(morpholine-4-dithiocarbamato-S,S′)antimony(III) (1.6 g; 3.4 mmol)
to sodium acetate 1 (0.3 g; 3.4 mmol) in hexane (~40 ml)
(Scheme 3). The resulting mixture was refluxed for ~5 h and cooled,
and the precipitated sodium salt was removed by filtration. The
final product was obtained to reduce the solvent under vacuum. It
was recrystallized with a 1:1 solution of benzene–dichloromethane.
Compounds (2–7) were also synthesized by adopting the
similar procedure.
Synthesis of Compound 8 in 2:1 Molar Ratio
To ethane-1,2-dithiol 8 (0.2 g; 0.18 mmol) was added a hexane so-
lution (~40 ml) of chloro-bis(morpholine-4-dithiocarbamato-S,S′)
antimony(III) (1.8 g; 3.6 mmol) (Scheme 4). The reaction mixture
was refluxed for ~5 h and liberation of HCl was observed. The yel-
low-colored solids were obtained by reducing the solvent under
vacuum. It was recrystallized with dichloromethane solution.
The chemical structures of compounds 1-8 are given in Fig. 1.
Synthesis of Chloro-bis(morpholine-4-dithiocarbamato-S,S′)
antimony(III)
Synthesis of potassium morpholine-4-dithiocarbamate
Morpholine (3.48 g; 40 mmol) was dissolved in 14 ml methanol
(<10°C) and chilled; to this a chilled aqueous methanolic solution
of potassium hydroxide (2.24 g, 40 mmol) was added with con-
stant stirring. To this an ice-cold solution of carbon disulfide
(2.5 ml, 40 mmol) in methanol was added. The addition of carbon
disulfide solution results in a white-colored precipitate, which
was filtered and washed with ice-cold aqueous methanol and
recrystallized from hot water (Scheme 1).
Compound 1
Yield 89%; light-yellow solid; m.p. 155°C. MW found (calcd): 501
(505). Anal. Calcd for C12H19N2O4S4Sb (%): C 28.52; H 3.79;
N 5.54; S 25.38; Sb 24.10. Found (%): C 28.41; H 3.67; N 5.42;
S 25.14; Sb 23.89. UV λmax (nm): 253, 308, 360. FT-IR (KBr, cmꢀ1):
1
2963, 1790, 1790, 1479, 1260, 1048, 547, 343. H NMR (CDCl3, δ):
2.07 (s, 3H, ―OOCCH3), 3.74 (t, 4H, J = 4.8 Hz, ―CH2OCH2―),
Synthesis of tris(morpholine-4-dithiocarbamato-S,S′)antimony(III)
A hexane solution of SbCl3 (2.69 g; 11.8 mmol) was added
dropwise to the hexane solution of potassium morpholine-4-
dithiocarbamate (7.12 g; 35.3 mmol). A rapid color change to yel-
low was observed during the addition (Scheme 2a). The reaction
mixture was refluxed for ~5 h; the precipitated potassium chlo-
ride was filtered off and the filtrate was reduced (~20 ml) under
vacuum to obtain the product.
Scheme 3. Synthesis of bis(morpholine-4-dithiocarbamato-S,S′)antimony
(III) acetate.
Scheme 1. Synthesis of potassium morpholine-4-dithiocarbamate.
wileyonlinelibrary.com/journal/aoc
Copyright © 2014 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2014, 28, 605–613

Mixed bis(morpholine-4-dithiocarbamato-S,S′)antimony(III) complexes
1
1749, 1493, 1255, 1046, 329. H NMR (CDCl3, δ): 3.61(s, 2H,
―SCH2―), 3.74 (t, 4H, J = 4.8 Hz, ―CH2OCH2―), 4.10
(t, 4H, J = 4.8 Hz, ―CH2NCH2―), 9.78 (s, 1H, ―COOH). 13C
NMR (CDCl3, δ): 25.11 (―SCH2―), 50.41 (―CH2NCH2―),
66.01 (―CH2OCH2―), 175.48 (―COOH) 200.18 (―NCS2―).
Compound 5
Yield 85%; light-yellow solid; m.p. 161°C; MW found (calcd):
577 (583); Anal. Calcd for C17H21N2O5S4Sb (%): C 35.01; H
3.63; N 4.80; S 21.99; Sb 20.87. Found (%): C 34.89; H 3.51;
N 4.73; S 21.80; Sb 20.81. UV λmax (nm): 249, 304, 347. FT-IR
(KBr, cmꢀ1): 3182, 2962, 1699, 1699, 1490, 1250, 1066, 541¸
343. 1H NMR (CDCl3, δ): 3.75 (t, 4H, J = 4.8 Hz, ―CH2OCH2―),
4.04 (t, 4H, J = 4.8 Hz, ―CH2NCH2―), 6.86 (dd, 1H, J = 7.6, 7.4 Hz,
ArH3), 6.94 (d, 1H, J = 8.4 Hz, ArH5), 7.42 (dd, 1H, J = 8.4, 7.4 Hz,
ArH4), 7.87 (d, 1H, J = 7.6 Hz, ArH2), 10.34 (s, 1H, ArOH). 13C NMR
(CDCl3, δ): 50.41 (―CH2NCH2―), 66.02 (―CH2OCH2―), 113.26
(ArC1), 117.43 (ArC5), 119.19 (ArC3), 130.96 (ArC2), 135.83 (ArC4),
161.74 (ArC6), 174.65 (―COO―), 199.03 (―NCS2―).
Scheme 4. Synthesis of di-μ-ethane-1,2-dithiolato-bis(morpholine-4-dithiocarbamato-
S,S’)antimony(III).
Compound 6
Yield 69%; light-yellow solid; m.p. 179°C (dec); MW found (calcd):
516 (521). Anal. Calcd for C23H23N2O2S5Sb (%): C 29.95; H 4.45;
N 5.37; S 30.75; Sb 23.35. Found (%): C 29.88; H 4.37; N 5.27;
S 30.71; Sb 23.28. UV λmax (nm): 260, 314, 350. FT-IR (KBr, cmꢀ1):
1
2965, 1487, 1048, 341. H NMR (CDCl3, δ): 1.04 (t, 3H, J = 4.8 Hz,
―CH2CH3), 1.71 (m, 2H, J = 7.5 Hz, ―CH2CH2CH3), 2.63 (t, 2H,
J = 4.8 Hz, ―SCH2―), 3.74 (t, 4H, J = 4.8 Hz, ―CH2OCH2―),
4.02 (t, 4H, J = 4.8 Hz, ―CH2NCH2―). 13C NMR (CDCl3, δ): 13.62
(―CH2CH3), 29.43 (―CH2CH2CH3), 22.12 (―SCH2―), 50.62
(―CH2NCH2―), 66.10 (―CH2OCH2―), 199.78 (―NCS2―).
Figure 1. Chemical structures of compounds 1–8.
4.09 (t, 4H, J = 4.8 Hz, ―CH2NCH2―). 13C NMR (CDCl3, δ): 23.54
(―OOCCH3), 50.55 (―CH2NCH2―), 66.11 (―CH2OCH2―),
Compound 7
176.82 (―OOCCH3), 200.24 (―NCS2―).
Yield 80%; light-yellow solid; m.p. 113°C; MW found (calcd): 549
(555). Anal. Calcd for C16H21N2O2S5Sb (%): C 34.60; H 3.81;
N 5.04; S 28.86; Sb 21.92. Found (%): C 34.49; H 3.75; N 4.96;
S 28.80; Sb 21.84. UV λmax (nm): 258, 302, 362. FT-IR (KBr, cmꢀ1):
Compound 2
Yield 91%; light-yellow solid; m.p. 122°C. MW found (calcd): 561
(567). Anal. Calcd for C17H21N2O4S4Sb (%): C 35.99; H 3.73; N
4.94; S 22.61; Sb 21.46. Found (%): C 35.83; H 3.68; N 4.81; S 22.54;
Sb 26.41. UV λmax (nm): 244, 310, 351. FT-IR (KBr, cmꢀ1): 2965,
1
2964, 1482, 1045, 338. H NMR (CDCl3, δ): 3.73 (t, 4H, J = 4.6 Hz,
―CH2OCH2―), 4.02 (t, 4H, J = 4.6 Hz, ―CH2NCH2―), 7.26
(m, 3H, J = 6.5 Hz, ArH3–5), 7.51 (d, 1H, J = 7.2 Hz, ArH2,6). 13C
NMR (CDCl3, δ): 50.74 (―CH2NCH2―), 66.02 (―CH2OCH2―),
127.53 (ArC4), 129.12 (ArC2,6), 135.16 (ArC3,5), 137.04 (ArC1),
198.56 (―NCS2―).
1
1696, 1696, 1481, 1252, 1050, 548, 328. H NMR (CDCl3, δ): 3.74
(t, 4H, J = 4.8 Hz, ―CH2OCH2―), 4.10 (t, 4H, J = 4.8 Hz, ―CH2NCH2―),
7.45 (t, 1H, J = 7.6 Hz, ArH3,5), 7.60 (t, 1H, J = 7.6 Hz, ArH4), 8.10 (d, 1H, J
= 7.6 Hz, ArH2,6). 13C NMR (CDCl3, δ): 50.55 (―CH2NCH2―), 66.12
(―CH2OCH2―), 128.42 (ArC3,5), 129.97 (ArC1), 130.16 (ArC2,6),
133.56 (ArC4), 171.95 (―OOCC6H5), 200.31 (―NCS2―).
Compound 8
Yield 81%; yellow solid; m.p. 159°C; MW found (calcd): 978 (984);
Anal. Calcd for C22H36N4O4S10Sb2 (%): C 26.83; H 3.68; N 5.69;
S 32.56; Sb 24.73. Found (%): C 26.71; H 3.62; N 5.63; S 32.47; Sb
24.64. UV λmax (nm): 244, 313, 357. FT-IR (KBr, cmꢀ1): 2961,
Compound 3
Yield 72%; yellow solid; m.p. 205°C (dec.); MW found (calcd): 561
(567); Anal. Calcd for C12H19N2O3S5Sb (%): C 27.64; H 3.67; N 5.37; S
30.75; Sb 23.35. Found (%): C 27.55; H 3.61; N 5.33; S 30.68; Sb 23.28.
UV λmax (nm): 240, 313, 354. FT-IR (KBr, cmꢀ1): 2963, 1721, 1487,
1257, 1052, 334. 1H NMR (CDCl3, δ): 2.40 (s, 3H, ―SOCCH3), 3.74 (t,
4H, J = 4.8 Hz, ―CH2OCH2―), 4.10 (t, 4H, J = 4.8 Hz, ―CH2NCH2―).
13C NMR (CDCl3, δ): 34.39 (―SOCCH3), 50.56 (―CH2NCH2―), 66.06
(―CH2OCH2―), 197.42 (―SCOCH3), 199.33 (―NCS2―).
1
1493, 1052, 331. H NMR (CDCl3, δ): 3.58 (s, 2H, ―SCH2CH2S―),
3.69 (t, 4H, J = 4.8 Hz, ―CH2OCH2), 4.01 (t, 4H, J = 4.8 Hz,
―CH2NCH2―). 13C NMR (CDCl3, δ): 40.12 (―SCH2CH2S―), 50.43
(―CH2NCH2―), 66.18 (―CH2OCH2―), 199.95 (―NCS2―).
The mass spectra of compounds 1, 4 and 6 are shown in Figs
S1–S3 (supporting information) and possible formulae of the
fragments and their m/z ratios are as follows.
Compound 4
Compound 1
Yield 41%; whitish semi-solid; MW found (calcd): 531 (537). Anal.
Calcd for C12H19N2O4S5Sb (%): C 26.82; H 3.56; N 5.21; S 29.33; Sb
22.66. Found (%): C 26.77; H 3.48; N 5.14; S 29.19; Sb 22.58. UV
λmax (nm): 257, 306, 360. FT-IR (KBr, cmꢀ1): 3344, 2964, 1749,
500.9 (12) [Mꢀ4H]+, 488.9 (9) [MꢀCH3]+, 460.8 (4) [MꢀC2H3O]+,
444.9 (100) [MꢀC2H3O2]+, 428.9 (8) [MꢀC2H3O3]+, 372.8 (4)
[MꢀC6H11O3]+, 356.9 (28) [MꢀC6H11O4]+, 300.8 (13) [MꢀC10H19O4]+,
185.8 (26) [MꢀC12H19N2S2O4]+.
Appl. Organometal. Chem. 2014, 28, 605–613
Copyright © 2014 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

H. P. S. Chauhan et al.
Compound 4
n–π* transition at 240–260 nm involving the transition of non–
bonding electrons of sulfur atom to an antibonding π-orbital[39]
and the presence of low-intensity bands at 340–360 nm, probably
due to charge transfer transition of dithiocarbamate group.[39]
Compounds 1–5 also show medium to strong intensities of absorp-
tion between 246 and 260 nm owing to the chromophoric group
(C¼O) of corresponding oxygen or sulfur donor ligands.[41]
476.8 (13) [MꢀC2H3O2]+, 444.9 (100) [MꢀC2H3O2S]+, 428.9 (8)
[MꢀC2H3O3S]+, 372.8 (4) [MꢀC6H11O3S]+, 356.9 (28) [MꢀC6H11O4S]+,
300.8 (12) [MꢀC10H19O4S]+, 185.8 (26) [MꢀC12H19N2O4S3]+.
Compound 6
504.9 (19) [MꢀCH3]+, 476.8 (24) [MꢀC3H7]+, 444.9 (100)
[MꢀC2H3O2S]+, 428.9 (9) [MꢀC3H7OS]+, 372.8 (5) [MꢀC7H15OS]+,
356.9 (40) [MꢀC7H15O2S]+, 300.8 (16) [MꢀC11H23O2S]+, 185.8
(34) [MꢀC13H23N2O2S3]+.
FT-IR and Far-IR Spectral Studies
The presence of medium- to strong-intensity bands between 1696
and 1790 cmꢀ1 and between 1250 and 1260 cmꢀ1 may be
assigned to asymmetric υ(COOꢀ) and symmetric υ(COOꢀ) groups
of the corresponding ligands, respectively.[41] The bands that ap-
peared in the stretching frequency region 1479–1493 cmꢀ1 have
been attributed to the polar υ(C―S) partial double bond of
―NCS2 moieties.[36] The strong band due to υ(C―S) known as
the thiocarbonyl group, observed at 1046–1066 cmꢀ1, has been
used to determine the mode of binding of dithiocarbamate groups.
However, these bands have been split into two signals due to the
anisobidentate mode of binding of the dithiocarbamate group.[42]
The band due to the morpholinyl υ(C―O―C) group appeared at
1106–1114 cmꢀ. 1 A broad band has been observed at 3344 cmꢀ1
(for compound 4) and 3182 cmꢀ1 (for compound 5) due to pheno-
lic and carboxylic ―OH groups, respectively.
Antimicrobial Studies
The well diffusion method (WDM) was used for the antimicrobial
screening test.[38a,b] Four human pathogenic bacterial species
(Escherichia coli (ATCC 9637) (Gꢀ), Pseudomonas aeruguinosa
(ATCC 25619) (Gꢀ), Staphylococcus aureus (ATCC 9144) (G+) and
Bacillus subtilis (ATCC 6051) (G+)) and two plant fungal species
(Aspergillus niger (ATCC 9029) and Trichoderma ressie (ATCC 164))
were used in vitro to determine the bactericidal and fungicidal
activities of the complexes, respectively. Chloramphenicol and
terbinafine were used as standard drugs for antibacterial and anti-
fungal screening, respectively.
The band observed in the regions 541–548 cmꢀ1 and 329–343 cmꢀ1
are connected with υ(Sb―O) and υ(Sb―S) stretching, which con-
firms the bonding of metal to oxygen and metal to sulfur, respec-
tively.[26] The FT-IR spectra of compounds 1 and 5 are shown in
Figs S4 and S5 (supporting information), respectively.
Method
An appropriate amount of compound was dissolved in DMF to
obtain 200 μg mlꢀ1 concentration solutions. Further, the solu-
tions were diluted to obtain the required concentrations of 100
and 50 μg mlꢀ1. Each investigated microorganism (0.5 ml solu-
tion) was added to a sterile nutrient agar (for bacteria)/dextrose
agar (for fungi) medium just before solidification, then poured
on to sterile Petri dishes (9 cm in diameter) and left to solidify.
Three holes (wells) were made in each dish using a sterile cork
borer (6 mm in diameter) and then a 0.1 ml solution in DMF
(50, 100 and 200 μg mlꢀ1) of the tested compound was poured
into these holes. The dishes were incubated at 37°C (24 h) for
bacteria and at 30°C (72 h) for fungi, where clear or zones of inhi-
bition were detected around each hole. Inhibitory activity was
measured (in mm) as the diameter of the zones of inhibition.
To determine the influence of DMF on microorganisms, a
quantity of 0.1 ml DMF alone was also used as a control under
the same conditions and, by subtracting the diameter of inhibi-
tion zone resulting with DMF from that obtained in each case,
both antibacterial and antifungal activity could be calculated as
a mean of three replicates.[39]
Multinuclear NMR Spectral Studies
The ―NCH2 and ―OCH2 protons of the morpholine ring show a
triplet at δ 4.01–4.10 and δ 3.69–3.75, respectively.[26,41,43,44] Com-
plexes 4 and 5 exhibit a singlet at δ 9.78 and δ 10.34 due to ―OH
proton. In addition, the oxygen or sulfur donor ligand of the com-
plexes also shows expected proton resonance, as summarized in
the analytical data section. The 1H NMR spectra of compounds 1
and 7 are shown in Figs S6 and S7 (supporting information),
respectively.
Likewise, the 13C NMR spectra of morpholinyl carbons show
signals at δ 50.41–50.62 and δ 66.02–66.18 due to ―NCH2 and
―OCH2 carbon, respectively. A weak signal at δ 199.03–200.31
has been observed due to NCS2 carbon resonance, indicating
the anisobidentate mode of coordination of dithiocarbamate.[45]
The compound containing the COO group also exhibits a weak
signal at δ 171.95–197.42. The 13C NMR spectra of compounds
1 and 7 are shown in Figs S8 and S9 (supporting information),
respectively.
Results and Discussion
Synthesis and Characterization of Antimony(III) Complexes
Bis(morpholine-4-dithiocarbamato-S,S′)antimony(III) complexes
were synthesized by the reactions of chloro-bis(morpholine-
4-dithiocarbamato-S,S′)antimony(III) with oxygen or sulfur donor
ligands in 1:1 (Scheme 4) or 2:1 (Scheme 5) molar ratios in
refluxing hexane solution for ~5 h.
Structure Elucidation
The IR spectra of these complexes reveal the expected stretching
frequency regions of the υ(C―S), υ(C―S), υ(COOꢀ), υ(C―O―C),
υ(Sb―O) and υ(Sb―S), in which the υ(C―S), υ(Sb―O) and
υ(Sb―S) bands are of significance, as these bands provide infor-
mation about M―L bonding as well as the mode of binding. The
bands appearing in the region 541–548 cmꢀ1 due to υ(Sb―O)
and 329―343 cmꢀ1 due to υ(Sb―S) vibrations confirm the
bonding of metal to oxygen and metal to sulfur, respectively.
The 13C NMR signal at around δ 200 due to the NCS2 moiety
UV–Visible Spectral Studies
The absorption band of C―S chromophore appeared in the range
302–313 nm due to intramolecular π–π* transition in dithiocarba-
mate moieties.[40] The C―S group of the dithiocarbamate showed
wileyonlinelibrary.com/journal/aoc
Copyright © 2014 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2014, 28, 605–613

Mixed bis(morpholine-4-dithiocarbamato-S,S′)antimony(III) complexes
Figure 2. Proposed structure for (a) bis(morpholine-4-dithiocarbamato-
S,S′)antimony(III) acetate and (b) di-μ-ethane-1,2-dithiolato-bis(morpholine-
4-dithiocarbamato- S,S′)antimony(III).
and the presence of a strong band at 1046–1066 cmꢀ1 due to the
v(C―S) group indicates an anisobidentate mode of bonding of
the DTC group.[45] Along with these, the 1H and 13C NMR spectral
data help us to understand the structural framework of the
complexes. Thus, on the basis of results obtained by the above
spectral techniques, it may be concluded tentatively that the an-
timony(III) complexes adopted a distorted octahedral geometry
with a lone pair of electrons occupying one of the triangular faces
of octahedra (Fig. 2). In addition, powder XRD studies show that
the complexes are crystalline in nature with a nano-range particle
size (16.32–19.97 nm) and having a monoclinic crystal system
indicating the lower symmetry of the complexes.
Figure 4. Powder XRD pattern of bis(morpholine-4-dithiocarbamato-S,S′)
antimony(III) thioglycolate (4).
structures, nano-range particle size (16.32–19.97 nm), lower sym-
metry (monoclinic) with unit cell volume V = 4823.35 × 10ꢀ8 cm–
3(1), V = 5684.23 × 10ꢀ8 cm–3(4) and V = 4825.79 × 10ꢀ8 cmꢀ3
(6). The Debye–Scherrer formula was used to determine the aver-
age crystallite size using full width at half-maximum (FWHM) of
the diffraction peaks:[43,46]
Kλ
D ¼
B cosθ
Powder XRD Studies
where D = particle size, K = is a constant (value = ~0.9), λ = wave-
length, B = FWHM and θ = Bragg angle.
Powder XRD studies (0° < 2θ < 60°) were carried out in order to
provide insight into the lattice parameters and unit cell volume of
the complexes. The diffraction pattern for compounds 1, 4 and 6
are shown in Figs 3, 4 and 5, respectively.
Interplanar d spacing and unit cell volume of the synthesized
complexes were calculated using the following formulae:[47]
Interplaner d spacing observed for complexes was matched
with standard diffraction database JCPDS card Nos. 25–1887,
75–2389, 48–2480, 77–0285 (Tables 1, 2 and 3). It has been
observed that the complexes are found to have crystalline
ꢀ
ꢁ
1
d2
1
h2 k2 sin2β l2 2hl cosβ
¼
þ
þ
ꢀ
c2
sin2β
b2
V ¼ abcsinβ
a2
ac
Figure 3. Powder XRD pattern of bis(morpholine-4-dithiocarbamato-S,S′)
antimony(III) acetate (1).
Figure 5. Powder XRD pattern of bis(morpholine-4-dithiocarbamato-S,S′)
antimony(III) 1-propanethiolate (6).
Appl. Organometal. Chem. 2014, 28, 605–613
Copyright © 2014 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

H. P. S. Chauhan et al.
Table 1. Experimental data and calculated results for powder
XRD pattern of bis(morpholine-4-dithiocarbamato-S,S′)antimony(III)
acetate (1)
Table 2. Experimental data and calculated results for powder XRD of
bis(morpholine-4-dithiocarbamato-S,S′)antimony(III)thioglycolate (4)
2θ
d spacing
d spacing
Relative
h
k
l
2θ
d spacing
observed
d spacing
calculated
Relative
intensity (I/I0)
h
k
l
observed
calculated
intensity (I/I0)
6.41
13.77
6.92
6.69
5.87
5.13
4.60
4.49
3.91
3.85
3.82
3.71
3.69
3.54
3.44
3.36
2.85
2.52
2.51
2.38
2.08
2.04
1.97
1.89
13.85
6.92
6.52
5.77
5.05
4.62
4.43
4.99
3.70
3.67
3.57
3.70
3.43
3.46
3.26
2.84
2.43
4.41
2.38
2.05
1.96
1.96
1.81
100
33
27
44
18
19
65
30
15
23
23
19
20
13
15
15
13
10
8
0
0
0
1
1
1
0
1
1
2
2
2
2
2
0
2
1
3
0
1
1
2
2
4
2
8.50
10.40
8.10
7.31
5.08
4.28
3.98
3.79
3.64
3.58
3.48
3.37
3.28
3.09
3.01
2.98
2.92
2.87
2.73
2.69
2.52
2.50
2.47
2.38
2.28
2.22
2.20
2.19
2.17
2.11
2.08
2.02
2.00
2.00
10.19
8.10
7.16
5.22
4.29
3.91
4.01
3.65
3.76
3.40
3.34
3.12
3.28
3.14
2.91
3.06
3.10
2.92
2.70
2.74
2.59
2.62
2.51
2.30
2.28
2.42
2.24
2.26
2.19
2.21
2.02
2.01
2.20
2
100
27
16
15
12
11
10
10
10
13
9
2
0
2
0
3
1
1
1
0
4
0
1
1
2
5
0
5
5
5
6
5
6
6
6
7
7
6
7
7
7
7
8
8
7
0
0
2
0
3
3
1
4
0
0
4
3
3
1
0
1
1
0
0
1
1
1
0
0
1
2
1
1
1
1
0
0
2
12.77
13.22
15.08
17.25
19.27
19.74
22.73
23.07
23.24
23.97
24.07
25.14
25.85
26.49
31.32
35.52
35.76
37.72
43.55
44.25
46.00
48.21
0
0
4
2
10.92
12.11
17.46
20.76
22.32
23.45
24.43
24.88
25.58
26.43
27.17
28.87
29.66
29.95
30.65
31.11
32.74
33.25
35.60
35.85
36.27
37.76
39.48
40.53
40.96
41.26
41.66
42.87
43.49
44.80
45.23
45.34
0
0
0
3
1
0
4
1
0
6
2
0
5
ꢀ5
ꢀ1
2
ꢀ1
0
4
0
0
1
6
0
2
1
0
0
4
0
3
11
17
16
12
12
7
3
0
8
ꢀ1
7
0
4
0
9
ꢀ2
1
0
2
ꢀ2
0
6
3
11
13
12
12
3
8
0
8
0
9
ꢀ4
ꢀ2
1
11
9
0
12
10
11
7
0
7
0
3
Lattice parameter calculated: a = 27.80 Å, b = 7.39 Å and c = 27.69 Å;
angle β = 91.46°; unit cell volume V = 5684.23 × 10ꢀ8 cmꢀ3; particle
size = 16.32 nm.
1
10
6
ꢀ1
ꢀ3
ꢀ2
1
12
14
11
6
(1, 4 and 6), and Table 4 summarizes the observed and calculated
results.
ꢀ3
2
The thermogram of compound 1 in Fig. S10 exhibits three
steps of mass loss; the first step can be attributed to the loss of
the CH3COO fragment with an observed mass loss 11.52% (calcu-
lated 11.67%) within the temperature range 40–260°C. The
observed (28.87%) and calculated (28.52%) mass loss for the sec-
ond step (260–400°C) supports removal of two C4H8O fragments.
The final step takes place between 400 and 590°C correspond to
the removal of 2 NCS and ½ S moieties, leaving the antimony sul-
fide as residue. The overall observed and calculated mass loss
amounts on complete degradation of complexes to antimony
sulfide were 67.12% and 66.34 %, respectively. The DTA curve
shows endothermic peaks at 223, 302 and 491°C for three con-
secutive decomposition steps.
Compound 4 also exhibits a three-step mass loss, as shown in
Fig. S11. The first step occurs within the range 40–328°C in which
some of the organic part of the ligands (HCO2 and 2 C2H4O) was
lost. The observed and calculated mass losses were 24.29% and
24.76%, respectively. In second step, which occurred between
328 and 420°C, with an observed mass loss of 12.98% corre-
sponding to the removal of C5H10 fragment (calculated 13.03%)
and we obtain C2N2S5Sb as the remaining part. The third step
corresponds to further decomposition of C2N2S5Sb and subse-
quent formation of antimony sulfide in a temperature range of
420–600°C. The formation of pure antimony sulfide was con-
firmed by observed (32.66%) and calculated (31.61%) percent-
ages of remaining material. In the DTA curve three consecutive
endothermic peaks were observed, at 253, 374 and 508°C.
9
0
8
1
7
0
Lattice parameter calculated: a = 20.80 Å, b = 16.19 Å and c = 14.61 Å;
angle β = 101.47°; unit cell volume V = 4823.35 × 10ꢀ8 cmꢀ3; particle
size = 19.97 nm.
ESI–Mass Spectral Studies
The mass spectral fragmentation of a few complexes (1, 4 and 6)
has been recorded on a Waters Micromass Q-ToF micro mass
spectrometer. Mass spectrometry is one of the most important
tools to determine the molecular weight of complexes[48a–c] with
the help of the molecular ion peak. These complexes do not give
a molecular ion peak, which may be due to the pyrolytic decom-
position or to fragmentation of the molecular ion in the ioniza-
tion chamber.[48d] However, all three complexes show a base
peak at m/z 444.9, indicating fragmentation of the M―L bond,
and supporting the strong chelating nature of the dithiocarba-
mate compared with the other hetero ligands used.
Thermal Studies
Figures S10, S11 and S12 (supporting information) show the ther-
mogram (TG/DTA curves) of three of the synthesized complexes
wileyonlinelibrary.com/journal/aoc
Copyright © 2014 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2014, 28, 605–613

Mixed bis(morpholine-4-dithiocarbamato-S,S′)antimony(III) complexes
Table 3. Experimental data and calculated results for powder XRD of bis
(morpholine-4-dithiocarbamato-S,S’)antimony(III) 1-propanethiolate (6)
In the case of complex 6, we observed two steps of weight
loss, as shown in Fig. S12. The decomposition initiates with re-
moval of C3H7 and 2 C4H8O within the range of 40–306°C. The ob-
served and calculated mass losses were 35.58% and 35.90%,
respectively. The second step corresponds to the loss of 2 NCS
and ½ S3 fragments within the temperature range of 306–600°C
and we obtained ½ Sb2S3 as the remaining material on comple-
tion of this step. The observed (33.27%) and calculated (32.57%)
percentages of residual material support the formation of anti-
mony sulfide. DTA analysis shows endothermic peaks at 219
and 440°C for the first and second steps, respectively.
2θ
d spacing
observed
d spacing
calculated
Relative
intensity (I/I0)
h
k
l
8.50
10.40
8.08
7.32
5.27
5.22
5.17
4.26
4.06
3.97
3.64
3.58
3.47
3.37
3.20
3.02
3.02
3.00
2.98
2.81
2.72
2.67
2.60
2.56
2.51
2.50
2.39
2.29
2.21
2.19
2.17
2.12
2.09
2.02
2.01
10.19
8.08
7.17
5.39
5.09
5.21
4.30
4.04
3.96
3.66
3.70
3.40
3.34
3.19
3.14
3.15
3.05
2.91
2.92
2.69
2.67
2.64
2.60
2.59
2.61
2.50
2.29
2.25
2.24
2.26
2.18
2.21
2.02
2.01
100
70
59
38
53
48
38
31
34
45
28
49
26
22
28
21
19
21
21
22
19
31
29
19
20
17
17
32
26
23
32
20
16
16
2
0
2
0
1
0
3
1
4
4
0
4
0
1
5
5
5
5
0
1
6
6
6
6
6
6
6
7
7
7
7
7
7
8
8
0
0
2
1
0
0
3
0
0
4
1
0
4
0
1
1
1
0
1
0
0
1
0
1
1
0
0
0
1
1
1
1
0
0
10.94
12.08
16.81
16.97
17.17
20.84
21.90
22.38
24.47
24.88
25.63
26.43
27.85
29.51
29.58
29.81
29.93
31.42
32.86
33.56
34.52
35.00
35.76
35.85
37.57
39.24
40.76
41.15
41.51
42.71
43.32
44.80
45.13
0
0
3
4
1
1
0
Antimicrobial Studies
1
ꢀ1
ꢀ2
6
For in vitro antimicrobial activity, free ligands and their metal com-
plexes have been tested against four human pathogenic bacterial
species (Figs 6 and 7) – Escherichia coli, Pseudomonas aeruguinosa,
Staphylococcus aureus and Bacillus subtilis – and two plant fungal
species (Fig. 8) – Aspergillus niger and Trichoderma ressie – at three
different concentrations (50, 100 and 200 μg mlꢀ1).
The inhibition activities of free ligands and their antimony(III)
complexes were compared with standard antibacterial (chloram-
phenicol) and antifungal (terbinafine) drugs. It was observed that
the coordination of ligands to the metal center enhanced antimi-
crobial activities and showed varied antibacterial and antifungal
activities.
1
1
ꢀ1
0
ꢀ2
7
ꢀ7
0
1
ꢀ1
2
The results of an antimicrobial screening test a comparison
between the activities of the free ligands, their synthesized anti-
mony(III) complexes and standard drugs used for references are
as follows:
ꢀ2
1
3
(i) The synthesized complexes exhibit equal or greater activ-
ities against bacterial and fungal strains compared with
standard antibacterial (chloramphenicol) and antifungal
(terbinafine) drugs.
(ii) The maximum zone of inhibition of 20 mm was recorded
for complex 3 against Trichoderma ressie at 200 μg mlꢀ1
concentration.
(iii) All the ligands and their metal(III) complexes show <10 mm
zone of inhibition (ZI) at 50 μg mLꢀ1 concentration against
all microorganisms.
(iv) Complexes 2, 3 and 8 are most active (17–20 mm ZI)
against both of the fungal species (Aspergillus niger and
1
2
ꢀ2
1
ꢀ3
2
0
1
Lattice parameter calculated: a = 20.79 Å, b = 16.16 Å and c = 14.65 Å;
angle β = 101.41°; unit cell volume V = 4825.79 × 10ꢀ8 cmꢀ3
;
particle size = 17.13 nm.
Table 4. TG/DTA analysis data of compounds 1, 4 and 6
Compound No. Step
Decomposition
temperature range (°C)
Mass losses (%)
found (calc.)
Fragments
lost
Remaining
fragments
DTAmax (°C)
1
4
6
I
II
III
I
40–260
260–400
400–590
40–328
11.52 (11.67)
28.87 (28.52)
26.73 (26.12)
24.29 (24.76)
12.98 (13.03)
30.07 (30.52)
35.58 (35.90)
31.15 (31.45)
C2H3O2
C10H16N2S4Sb
C2N2S4Sb
223d
302d
491
253d
374d
508d
219d
440d
2C4H8O
a
2NCS + ½S
½ Sb2S3
CHO2 + 2C2H4O C7H10N2S5Sb
II
III
I
328–420
420–600
40–306
C5H10
C2N2S5Sb
b
2NC + ½S5
½Sb2S3
C3H7 + 2C2H4O C2N2S5Sb
c
II
306–600
2NCS + ½S3
½ Sb2S3
aRemaining material, found (calc.) = 32.88 (33.61).
bRemaining material, found (calc.) = 32.66 (31.61).
cRemaining material, found (calc.) = 33.27 (32.57).
dEndothermic reaction.
Appl. Organometal. Chem. 2014, 28, 605–613
Copyright © 2014 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc

H. P. S. Chauhan et al.
Figure 6. Antibacterial activity exerted by free ligands and synthesized
complexes with reference to standard drug against Gꢀ bacteria (E. coli and
S. aeruguinosa).
Figure 8. Antifungal activity exerted by free ligands and synthesized
complexes with reference to standard drug against A. niger and T. ressie.
a greater extent due to the overlap of the ligand’s orbital and
partial sharing of the positive charge of the central metal ion
with donor groups. Further, it enhances the delocalization of
π-electrons around the entire chelate ring and increases penetra-
tion of the complexes into microbial lipid membranes and
blocking of the metal binding sites in the enzymes of microor-
ganisms.[49] These complexes also disturb the respiration process
of the cell and thus block protein synthesis, which restricts
further growth of the organisms.
Conclusion
Antimony(III) complexes have been synthesized and character-
ized by various techniques, and evaluated for their biological
impact against some bacteria and fungi. The results tentatively
indicate that the complexes may have distorted octahedral
geometry with a stereochemically active lone pair of electrons,
crystalline in nature and a nano range particle size with mono-
clinic crystal system. TGA data proved that antimony sulfide
was the final degradation product. It was observed that the com-
plexes exhibit higher bactericidal and fungicidal activities than
the free ligands, as well as greater or equal activities compared
to standard drugs.
Figure 7. Antibacterial activity exerted by free ligands and synthesized
complexes with reference to standard drug against G+ bacteria (S. aureus
and B. subtilis).
Acknowledgments
Trichoderma ressie) as well as complexes 4 (17 mm ZI) and
6 (18 mm ZI) against Trichoderma ressie.
The authors thank the University Grant Commission (UGC), New
Delhi, for financial support (F.39–801/2010(SR)) for the accom-
plishment of this work. We are also thankful to the Sophisticated
Analytical Instrumentation Facility (SAIF), Chandigarh; CSMCRI,
Bhavanagr, Gujarat; and SAIF, Mumbai for ESI mass, TGA/DTA
and far-IR spectral studies, respectively. UGC-DAE-CSR, Indore,
and IISER, Bhopal, are gratefully acknowledged for powder XRD
studies and NMR (1H and 13C), respectively.
(v) The Gram-negative bacterium Escherichia coli shows resis-
tance for ligands 1,2 and 4–6 as well as Pseudomonas
aeruguinosa for ligand 4 at all concentrations. However,
the coordination of such ligands with metal center ex-
hibits pronounced activities (except complex 2, which
shows least activity with 9 mm IZ).
(vi) Staphylococcus aureus exhibits resistance for ligand 5,
whereas the metal complex shows good enough activity.
References
To explain the behavior of free ligands and their metal
complexes for microorganisms, it has been proposed that the
coordination of ligands reduces the polarity of the metal ion to
[1] a) P. J. Blower, J. R. Dilworth, Coord. Chem. Rev. 1987, 76, 121; b) V. K.
Jain, Coord. Chem. Rev. 1994, 135, 809; c) C. Silvestru, I. Haiduc,
wileyonlinelibrary.com/journal/aoc
Copyright © 2014 John Wiley & Sons, Ltd.
Appl. Organometal. Chem. 2014, 28, 605–613

Mixed bis(morpholine-4-dithiocarbamato-S,S′)antimony(III) complexes
Coord. Chem. Rev. 1996, 147, 117. d) E. S. Raper, Coord. Chem. Rev.
1996, 153, 199.
[27] a) H. P. S. Chauhan, S. Chourasia, Indian J. Chem. A 1995, 34, 664; b)
H. P. S. Chauhan, U. P. Singh, Appl. Organomet. Chem. 2006, 20, 404;
c) H. P. S. Chauhan, A. Bakshi, S. Bhatiya, Phosphorus Sulfur Silicon
Relat. Elem. 2011, 186, 345; d) H. P. S. Chauhan, S. Bhatiya, A. Bakshi,
Phosphorus Sulfur Silicon Relat. Elem. 2011, 186, 511.
[28] a) O. Savadogo, K. C. Mandal, Sol. Energy Mater. 1992, 26, 117; b) L. P.
Deshmukh, S. G. Holikatti, B. P. Rane, B. M. More, P. P. Hankare,
J. Electrochem. Soc. 1994, 41, 1779; c) M. T. S. Nair, Y. Pena, J. Campos,
V. M. Garcia, P. K. Nair, J. Electrochem. Soc. 1998, 145, 2113.
[29] K. Y. Rajpure, C. H. Bhosale, Mater. Chem. Phys. 2000, 64, 70.
[30] J. Grigas, J. Meshkauskas, A. Orliukas, Phys. Status Solidi A 1976, 37,
K39.
[2] a) J. D. Lebedda, R. A. Palmer, Inorg. Chem. 1971, 10, 2704; b) P. J.
Hauser, A. F. Schreiner, J. D. Gunter, W. J. Mitchell, M. K. DeArmond,
Theor. Chim. Acta 1972, 24, 78; c) J. D. Lebedda, R. A. Palmer, Inorg.
Chem. 1972, 11, 484; d) A. F. Schreiner, P. J. Hauser, Inorg. Chem.
1972, 11, 2706.
[3] a) L. Casella, M. Gullotti, R. Vigano, Inorg. Chim. Acta 1988, 121, 1124;
b) M. Gullotti, P. Casello, A. Pinter, E. Suardi, P. Zanello, S. Mangani,
J. Chem. Soc., Dalton Trans. 1989, 1979; c) E. Block, H. Y. Kang, G.
Ofori-Okai, J. Zubieta, Inorg. Chim. Acta 1989, 166, 155.
[4] a) A. Rieche, D. Martin, W. Schade, Arch. Pharm. 1963, 296, 770; b) M.
Schorr, W. Duerckheimer, P. Klatt, G. Laemmler, G. Nesemann, E.
Schrinner, Arzneim.-Forsch. 1969, 19, 1807; c) H. Bruer, U.D. Treuner,
US Patent 3855211, 1974; d) A.-N. El-Shorbagi, Arch. Pharm. 2000,
333, 281.
[5] a) W. Hanefeld, Arch. Pharm. 1977, 310, 409; b) M. A. Hussein, A.-N.
El-Shorbagi, A. R. Khallil, Arch. Pharm. 2001, 334, 305; c) T. Aboul-
Fadl, M. A. Hussein, A.-N. El-Shorbagi, A. R. Khallil, Arch. Pharm.
2002, 335, 438.
[6] a) H. A. G. Farbwerke, French Patent 2015026, 1970; b) M. Schorr, W.
Duerckheimer, L. Behrendt, D. Duewel, German Patent 1947746,
1971.
[31] D. Cope, US Patent 2875359, 1959.
[32] I. H. Kim, Mater. Lett. 2000, 43, 221.
[33] M. S. Ablova, A. A. Andreev, T. T. Dedegkaev, B. T. Melekh, A. B.
Pevtsov, N. S. Shendel, L. N. Shumilova, Sov. Phys. Semicond. 1976,
10, 629.
[34] J. A. Riddick, W. B. Bunger, Techniques of Chemistry (Organic Solvents),
Wiley–InterScience, New York, 1970.
[35] H. D. Yin, J. Zhai, Y. Y. Sun, D. Q. Wang, Polyhedron 2008, 27, 663.
[36] N. Manav, A. K. Mishra, N. K. Kaushik, Spectrochim. Acta A 2006,
65, 32.
[37] A. I. Vogel, A Textbook of Quantitative Chemical Analysis, Saurabh
Printers, New Delhi, 2008.
[7] A. Warshawsky, I. Rogachev, Y. Patil, A. Baszkin, L. Weiner, J. Gressel,
Langmuir 2001, 17, 5621.
[8] K. Nishimura, T. Yasunaga, S. Kanada, S. Katayama, Japanese Patent
53-029932, 1978.
[38] a) L. Boyanova, G. Gergova, R. Nikolov, S. Derejian, E. Lazarova, N.
Katsrov, I. Mitov, Z. Krastev, J. Med. Microbiol. 2005, 54, 481. b)
H. P. S. Chauhan, A. Bakshi, S. Bhatiya, Appl. Organomet. Chem.
2010, 24, 317.
[9] Henkel, French Patent 1600071, 1970.
[10] Ciba-Geigy, British Patent 1301032, 1972.
[39] M. E. Ibrahim, A. A. H. Ali, F. M. M. Maher, J. Chem. Techn. Biotechnol.
1992, 55, 217.
[40] A. K. Mishra, N. Manav, N. K. Kaushik, Spectrochim. Acta A 2005, 61,
3097.
[41] H. P. S. Chauhan, S. Bhatiya, Spectrochim. Acta A 2012, 97, 1133.
[42] O. S. Jung, Y. S. Sohn, Bull. Korean Chem. Soc. 1988, 9, 365.
[43] H. P. S. Chauhan, A. Bakshi, J. Therm. Anal. Calorim. 2011, 105, 937.
[44] J. Sharma, Y. Singh, R. Bohra, A. K. Rai, Polyhedron 1996, 15, 1097.
[45] H. L. M. Van Gaal, J. W. Diesveld, F. W. Pijpers, J. G. M. Van Der Linden,
Inorg. Chem. 1979, 18, 3251.
[11] M. M. Orlinskii, B. S. Zimenkovskii, J. Pharm. Chem. 1998, 32, 516.
[12] R. Simsek, C. Safak, K. Erol, K. Vural, Trends J. Med. Sc. 1999, 29, 627.
[13] L. T. Strogonova, S. A. Bolshakova, T. N. Tuzhilkova, S. V. Amosova,
N. I. Ivanova, O. A. Tarasova, M. L. Alpert, J. Pharm. Chem. 1990, 24, 3.
[14] a) G. Faraglia, S. Sitran, D. Montagner, Inorg. Chim. Acta 2005, 358,
971; b) P. J. Heard, Prog. Inorg. Chem. 2005, 53, 1; c) O. Guzel, A.
Salman, Bioorg. Med. Chem. 2006, 14, 7804.
[15] V. F. Plyusnin, A. V. Kolomeets, V. P. Grivin, S. V. Larinov, H.
Lemmetyinen, J. Phys. Chem. A 2011, 115, 1763.
[16] M. D. Regulacio, N. Tomson, S. L. Stoll, Chem. Mater. 2005, 17, 3114.
[17] a) F. A. V. Sullivan, A. C. Lindaw, US Patent 3215703, 1965; b) R. C.
Kinstler, US Patent 3215704, 1965.
[18] B. P. Bongar, V. S. Sadavarte, L. S. Uppalla, J. Chem. Res. 2004, 9, 450.
[19] K. S. Siddiqi, S. A. A. Nami, L. Chebude, Y. Chebude, J. Braz. Chem. Soc.
2006, 17, 107.
[20] D. Zhang, J. Chen, Y. Liang, H. Zhou, Synth. Commun. 2005, 35, 521.
[21] S. S. Garje, V. K. Jain, Coord. Chem. Rev. 2003, 236, 35.
[22] R. A. Gencarelli, K. A. Hughes, J. F. Sierakowski, US Patent 3988249A
1976.
[46] H. P. Klug, L. E. Alexander, X-Ray Diffraction Procedures for Polycrystal-
line and Amorphous Materials, Wiley, New York, 1974.
[47] B. D. Cullity, Elements of X-Ray Diffraction, Addison-Wesley, Boston,
MA, 1958.
[48] a) D. F. Schoener, M. A. Olsen, P. G. Cummings, C. Basic, J. Mass,
Spectrom. 1999, 34, 1069; b) T. S. B. Baul, K. S. Singh, M. Holcápek,
R. Jirásko, E. Rivarola, A. Linden, J. Organomet. Chem. 2005, 690,
4232; c) L. Machucá, L. Dostál, R. Jambor, K. Handlíŕ, R. Jirásko, A.
Růžička, I. Císaŕová, J. Holeček, J. Organomet. Chem. 2007, 692,
3969; d) R. K. Gupta, A. K. Rai, R. C. Mehrotra, V. K. Jain, Polyhedron
1984, 3, 721.
[23] G. L. Willingham, US Patent 5145981A, 1992.
[24] a) M. I. Khan, S. Gul, I. Hussain, M. A. Khan, M. Ashfaq, I. U. Rahman, F.
Ullah, G. F. Durrani, I. B. Baloch, R. Naz, Org. Med. Chem. Lett. 2011, 1,
2; b) C. Vatsa, A. S. Pawar, S. S. Garje, Int. J. Chem. Stud. 2013, 1, 73.
[25] a) M. Hall, D. B. Sowerby, J. Chem. Soc., Dalton Trans. 1980, 1292; b)
J. R. Castro, P. Dale, M. F. Mahon, K. C. Molloy, L. M. Peter, Chem.
Mater. 2007, 19, 3219.
[49] B. G. Tweedy, C. Loeppky, Phytopathology 1968, 58, 1522.
Supporting Information
Additional supporting information may be found in the online
version of this article at the publisher’s web-site.
[26] H. P. S. Chauhan, J. Carpenter, S. Bhatiya, A. Bakshi, Phosphorus Sulfur
Silicon Relat. Elem. 2013, 188, 1713.
Appl. Organometal. Chem. 2014, 28, 605–613
Copyright © 2014 John Wiley & Sons, Ltd.
wileyonlinelibrary.com/journal/aoc