Page 1 of 12
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 01
January 2019
Available online: https://ejbss.org/ P a g e | 62
Structural Characterization of Polymeric HG (II)
and Dimeric Oxo-Bridged MN (II) Complexes
SATPAL SINGH
PGT CHEMISTRY
GSSS RAMSARA
FATEHABAD HARYANA
125053
ABSTRACT
Metal complexes of sulfur-nitrogen ligands derived from S-alkyl esters of dithiocarbazic
acid have been studied over the past few decades, not only because of their intriguing
coordination chemistry, but also because of their pronounced biological activities against
microbes, viruses, cancer cells, fungi and bacteria. The cyclization of 3-
acyldithiocarbazic acid esters, N-aroyldithiocarbazates and their salts to 1,3,4-
oxadiazole/thiadiazole-2-thiones in the presence of a acid/base or during complexation is
reported in the literature.
Several other methods are also available for the synthesis of oxadiazoles from acyclic
precursor which include oxidative cyclization of acylhydrazones, acylthiourea and
acylthiosemicarbazides. The cyclization of N2
-[bis(benzyl-sulfanyl)methylene]-2-
methoxybenzohydrazide to 2-benzylsulfanyl-5-(2-methoxyphenyl)-1,3,4-oxadiazole has
been carried out under normal condition without the use of any other reagents viz. base or
acid as already described in the case of other oxadiazoles.
Platinum assisted cyclization of S-methyl 3-acyl-2-methyldithiocarbazates under mild
conditions was reported by Bergamini and co-workers. A few papers are available on the
Page 2 of 12
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 01
January 2019
Available online: https://ejbss.org/ P a g e | 63
syntheses and X-ray studies of bis(benzylsulfanyl)methylene-2-acidhydrazide and
(benzylsulfanyl)-1,3,4-oxadiazole.
KEYWORDS:
Oxadiazole, Ester, Preparation
INTRODUCTION
A methanol suspension (15 mL) of HgCl2 (0.281 g, 10 mmol) was stirred with a
methanol solution of H2mbhe (0.250 g, 10 mmol). The precipitate obtained was
dissolved in methanol (15 mL), the resulting clear yellow solution was filtered off and
kept for crystallization where upon the single crystals of 1 suitable for X-ray analyses
were obtained by slow evaporation of the solution over a period of 25 days. The possible
pathway for the formation of new ligand (tot) and complex 1 is depicted in Scheme 1.
Yield: 55%, M.p. 190°C.
Fig.1 Ortep diagram of H2mbhe with 30% probability level.
ortep
Page 3 of 12
European Journal of Business &
Social Sciences
Available at https://ejbss.org/
ISSN: 2235-767X
Volume 07 Issue 01
January 2019
Available online: https://ejbss.org/ P a g e | 64
CH3
N
O
NH S
S
CH3
H
CH3
N
NH
O
S
S
CH3
CH3
N
N
O
S
H
CH3
N
N
O S
CH3
N
O
NH
S
S
CH3
H
HgCl2
MeOH
CH3
N
N
O S
Hg
S
S
CH3
Hg
H3C
SCH3
- HCl
Hg
S
CH3
S
n
H3C
N N
S O
S
H3C
S
tot
Scheme 1 Possible pathway for the formation of Hg3(tot)2(μ-SCH3)4]n from
H2mbhe
Synthesis of [Mn2(Hmbhe)2(μmbmst)2]CHCl3
A methanol solution (15 mL) of Mn(OAc)2·4H2O (0.125 g, 1 mmol) was stirred with a
methanol solution (15 mL) of H2mbhe (0.250 g, 2 mmol) and refluxed for 1 h at 80 oC.
The precipitate obtained was further stirred with H2mbhe (0.250 g, 2 mmol). The
resulting clear solution was filtered off, where upon the single crystals of 2 suitable for
X-ray analyses were obtained by slow evaporation of the solution over a period of 10
days. The 2-methyl benzoic acid (5,5′-bis-methylsufanyl-[2,3′]bi[[1,3,4]thiadiazolyl]-2'-
ylidene)-hydrazide (mbmst) generated during the reaction could not be isolated and