Thermal, spectral and biological studies of Co(II) and Cu(II) thiohydrazide and thiodiamine complexes

The synthesis, physico-chemical investigation and biological studies of some metal complexes of thiohydrazide and thiodiamine ligands are described. The ligands are obtained by the addition and the metathesis reaction with diphenyl amine. The ratio of the metal:ligand was 1:2 for all the complexes. Copper(II) and cobalt(II) complexes of type [Cu(L) 2 Cl 2 ] and [Co(L) 2 SO 4 ] [where L = N,N-diphenyl-N-thiohydrazide (L 1 ) and (N,N-diphenyl-N-thio)-1,3-propanediamine (L 2 )] have been synthesized. The synthesized copper and cobalt thiohydrazide and thiodiamine complexes were characterized by elemental analysis, FT-IR, mass, UV-Vis and 1 H NMR spectroscopic studies. The thiohydrazides and the thiodiamines coordinate as a bidentate N-S ligand. The binding sites are the azomethine nitrogen and thioamide sulphur. In vitro antifungal and in vitro antibacterial studies were performed against fungal and bacterial strains, Aspergillus fumigatus, Aspergillus flavus, Aspergillus niger and Escherichia coli, Pseudomonas aeruginosa respectively. Thermodynamic parameters such as order of reaction and activation energy (E a ) for the dehydration and decomposition reactions for one complex have also been evaluated.