Synthesis and Crystal Structure of a New Cadmium(II) Complex with 1,3-Thiazolidine-2-thione and Bipyridine Ligands

Abstract

There are different reports on the coordination mode 1,3-thiazolidine-2-thione to metals with both N and S as donor atoms. 1Interest in the coordination chemistry of the 1,3-thiazole derivatives arises from the presence of the heterocyclic skeleton in many biomolecules. 2 The crystal structure on the metal complexes of this ligand is scarce.This ligand exhibits a thiol-thione tautomerism, as shown in the following thiol-thione equilibrium (N=C-SH and -NH-C=S) [Scheme 1].3 Deprotonation in a basic media produces the thionate moiety, which is capable of a monodentate, bidentate or bridging coordination behavior utilizing either sulfur or nitrogen atoms, or both of them, in the complexes. 4 Zinc and cadmium complexes with N2S2 ligand cores are of interest as structural and spectroscopic models for metal binding sites in a number of metallothioneins and metalloregulatory proteins. 1,3-Thiazolidine-2-thione and 2,2′-bipyridine were purchased from Across. All of the solvents were used without additional purification. A polymeric complex, [Cd(C3H4NS2)2], was prepared by the method described in the literature. 3The product, [Cd(C3H4NS2)2(bipy)], was synthesized by adding 2,2′-bipyridine (3.12 g, 0.02 mol) in chloroform-dimethylformamide (1:1, 20 mL) to a suspension of a polymeric complex, [Cd(C3H4NS2)2] (1.42 g, 0.005 mol), in chloroform (10 mL) at room temperature. After stirring for two hours, a yellow solution was formed and then filtered to remove traces of solids, and was finally allowed to stand at room temperature. After several days, colorless crystals were collected and washed with toluene under a nitrogen atmosphere. These crystals were sensitive to air and suitable for a crystallographic study. The

Synthesis and spectroscopic characterization of cadmium(II) complexes of thiones and thiocyanate

“…Smaller shifts were also observed for cadmium chloride complexes of thiones [14]. The upfield shift is characteristic for sulfur coordination of thiones, ascribed to back-bonding of the metal d-orbitals to the antibonding -orbitals of sulfur in the 4C¼S bond, which reduces the 4C¼S bond order and shields the carbon of 4C¼S group resulting in a shift to higher field [11][12][13][14][15][16][17][18][19][20][21]. Reduction in -electron density on the exocyclic carbon-sulfur bond as a result of thione sulfur coordination to the metal is compensated by increase in bond order within the thioamide C-NH bond.…”

“…Consequently, we have reported complexes of Cu(I), Ag(I), Au(I), Cd(II) and Hg(II) with a number of thiones such as imidazolidine-2-thione [8][9][10][11][12][13][14]. Although several cadmium(II) complexes of thiones have been prepared and characterized using NMR spectroscopy and X-ray crystallography [7,[14][15][16][17][18][19][20][21], no spectroscopic reports are available about the coordination behavior of thiones towards cadmium thiocyanate. As a part of our continuing interest in the structural chemistry of metal-sulfur interactions, we report here the synthesis of a number of cadmium(II) thiocyanate complexes of thiones and their characterization by IR, 1 H and 13 C NMR spectroscopy.…”

Synthesis, spectral characterization and in vitro antibacterial evaluation and Petra/Osiris/Molinspiration analyses of new Palladium(II) iodide complexes with thioamides

“…[6][7][8][9][10][11][12][13][14][15][16] In view of great potential, several complexes of thioamides with Au(I), Ag(I), Cu(I) Zn(II) Mo(II), Cd(II) Pd (II) and Hg(II) have been widely studied. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] The treatment of infectious diseases still remains an important and challenging problem because of a combination of factors including emerging infectious diseases and the increasing number of multi-drug resistant microbial pathogens. In spite of a large number of antibiotics and chemotherapeutics available for medical use, at the same time the emergence of old and new antibiotic resistance created in the last decades revealed a substantial medical need for new classes of antimicrobial agents.…”

Synthesis, spectral characterization and antibacterial studies of palladium(II) complexes of heterocyclic thiones

“…6-Mercaptopurine and its riboside are anticancer metabolites and their complexes of Pd(II) and Pt(II) are known to exhibit antitumor activity [11][12][13]. In view of this importance, several complexes of thiones with Cu(I) [14][15][16][17], Ag(I) [18][19][20][21][22][23][24], Au(I) [25][26][27], Mo(II) [28], Pd(II) [29][30][31][32][33][34], Zn(II) [35][36][37][38][39], Cd(II) [39][40][41][42][43][44][45] and Hg(II) [46][47][48][49][50] have been widely studied. We have been interested in the spectral and structural chemistry of several metal ions with thiones in order to study their binding modes and to provide useful models for metalloproteins [16][17][18][19][20]26,…”