Studies on chromium(III) complexes with active nitrogen, oxygen and sulfur donor ketimines synthesized under microwave conditions

Abstract

Heterocyclic ketimines, 1-(2-furanyl)ethanonehydrazincarbothioamide (L¹H), 1-(2-furanyl)ethanone- hydrazincarboxamide (L²H), 1-(2-thienyl)ethanone hydrazincarbothioamide (L³H) and 1-(2-thienyl) ethanonehydrazincarboxamide (L⁴H), were prepared by the condensation of thiosemicarbazide and semicarbazide hydrochloride (in the presence of sodium acetate) in ethanol with the respective ketones by using microwave as well as conventional methods. Chromium(III) complexes have been prepared by mixing CrCl₃·6H₂O in 1:1 and 1:2 molar ratios with monobasic bidentate ketimines. The authenticity of the ligands and their complexes has been established by elemental analyses, melting point determinations, molecular weight determinations, EPR, infrared and UV spectral and X-ray powder diffraction studies. These studies showed that the ligands coordinated to the metal atom in a monobasic bidentate mode, coordinating through the nitrogen and sulfur/oxygen donor system. Thus, an octahedral environment around the metal atoms has been proposed. The growth-inhibiting potential of the ligands and complexes has been assessed against a variety of fungal and bacterial strains.

Keywords:

• chromium(III) complexes
• heterocyclic ketimines
• spectral studies
• antimicrobial activity

Acknowledgements

The authors are thankful to CSIR, New Delhi, and UGC, New Delhi, for financial assistance through grant no. 01(2307)/09/EMR-II and 36-1/2008(RAJ)(SR), respectively.