Microwave assisted synthesis, spectroscopic characterization and biological aspects of some new chromium(iii) complexes derived from N⁁O donor Schiff bases

Abstract

The present study is structured to address the development of green microwave processes in the manufacture of a new series of biologically potent (N⁁O) donor Schiff bases and their Cr(III) complexes. These have been characterized by elemental analysis, melting point and molecular weight determinations, IR, UV-vis and EPR spectral analysis, and X-ray powder diffraction studies. The bioefficient compounds have been synthesized by thermal as well as microwave assisted methods. The azomethine ligands 1-(2-pyridyl) ethanone isonicotinoyl hydrazone (L¹H) and 1-(2-naphthyl) ethanone isonicotinoyl hydrazone (L²H) have been synthesized by the condensation of 1-(2-pyridyl) ethanone and 1-(2-naphthyl) ethanone with isonicotinic acid hydrazide in a 1 : 1 molar ratio, using ethanol as a solvent. The Cr(III) complexes have been prepared by mixing CrCl₃·6H₂O in 1 : 1 and 1 : 2 molar ratios with ligands L¹H and L²H in methanol. The synthesized ligands and their new metal complexes have been screened in vitro for antimicrobial activity and in vivo for antifertility activity on male albino rats. The spectral data suggested a hexa-coordinated environment around the central metal ion. Physicochemical studies of the ligands and their Cr(III) complexes aided the construction of their proposed structures.