Synthesis, structure and antifungal activity of thiophene-2,3-dicarboxaldehyde bis(thiosemicarbazone) and nickel(II), copper(II) and cadmium(II) complexes: unsymmetrical coordination mode of nickel complex.

The reaction of nickel(II), copper(II) chlorides and cadmium(II) chloride and bromide with thiophene-2,3-dicarboxaldehyde bis(thiosemicarbazone) (2,3BTSTCH2) leads to a series of new complexes: [Ni(2,3BTSTCH)]Cl, [Cu(2,3BTSTC)], [CdCl2(2,3BTSTCH2)] and [CdBr2(2,3BTSTCH2)]. The crystal structures of the ligand and of [Ni(2,3BTSTCH)]Cl complex have been determined. In this case, we remark an unusual non-symmetrical coordination mode for the two functional groups: one acting as a thione and the second as a deprotonated thiolate. All compounds have been tested for their antifungal activity against human pathogenic fungi: Candida albicans, Candida glabrata and Aspergillus fumigatus, the cadmium complexes exhibit the highest antifungal activity. Cytotoxicity was evaluated using two biological methods: human MRC5 cultured cells and brine shrimp Artemia salina bioassay.

Synthesis, crystal structure, characterisation, and antifungal activity of 3-thiophene aldehyde semicarbazone (3STCH), 2,3-thiophene dicarboxaldehyde bis(semicarbazone) (2,3BSTCH2) and their nickel (II) complexes.

The reaction of nickel (II) chloride and bromide with 3-thiophene aldehyde semicarbazone (3STCH) and 2,3-thiophene dicarboxaldehyde bis(semicarbazone) (2,3BSTCH(2)) leads to the formation of a series of new complexes: [NiCl(2)(3STCH)(2)], [NiBr(2)(3STCH)(2)], [NiCl(2,3BSTCH(2))(H(2)O)]Cl, and [NiBr(2,3BSTCH(2))(H(2)O)]Br respectively. The crystal structures of the two ligands 3STCH, 2,3BSTCH(2) and of the complex [NiBr(2,3BSTCH(2))(H(2)O)]Br have been determined by X-ray diffraction methods. For all these complexes, the central ion is coordinated through the oxygen atom of the carbonyle and the azomethine nitrogen atom of the semicarbazone. The antifungal activity of the complexes and their corresponding ligands was evaluated against some strains of respectively, Candida albicans, Candida glabrata and Aspergillus fumigatus. The complexes with 3STCH and 2,3BSTCH(2) revealed interesting CMI(80) values specifically against C. glabrata. Cytotoxicity assay was also carried out in vitro on MRC5 cells.

Synthesis, crystal structure, characterization of zinc(II), cadmium(II) complexes with 3-thiophene aldehyde thiosemicarbazone (3TTSCH). Biological activities of 3TTSCH and its complexes.

The reaction of zinc(II) chloride, cadmium(II) chloride and bromide with 3-thiophene aldehyde thiosemicarbazone leads to the formation of a series of new complexes. They have been characterized by spectroscopic studies: infrared, (1)H NMR, and electronic spectra. The crystal structures of the compound [ZnCl(2)(3TTSCH)(2)] and [CdBr(2)(3TTSCH)(2)] have been determined by X-ray diffraction methods. For the complexes [ZnCl(2)(3TTSCH)(2)] and [CdBr(2)(3TTSCH)(2)], the central ion is coordinated through the sulfur, and for the complexes [CdCl(2)(3TTSCH)], [CdBr(2)(3TTSCH)] the ion is coordinated through the sulfur as well as azomethine nitrogen atom of the thiosemicarbazone. In addition, fungistatic and bacteriostatic activities of both ligand and complexes have been evaluated. Cadmium(II) complexes have shown the most significant activities.