Green synthetic approach and antimicrobial activity of bidentate schiff base ligands and their Ni(II) complexes under microwave irradiation

K. P. Srivastava, Sunil Kumar

Abstract

A rapid, efficient, clean and environmentally benign exclusive synthesis of Schiff bases as new ligands and their complexes with Ni(II) have been developed using condensation of 2-propyl-3-phenylquinazoline with semicarbazide (ppqs, L) and thiosemicarbazide (ppqt, L’) efficiently using alkali catalyst with excellent yields under microwave irradiation. This method provides several advantages such as environmental friendliness, simple work-up procedure, short reaction times, non-hazardous and excellent yield of products. The results are compared with conventional methods for their yield and reaction time. The Schiff base ligands and the complexes were characterized by micro-analytical, conductometric, magnetic and spectroscopic studies. All the Schiff bases were bidentate (NO donor) ligands. All complexes were found to be six co-ordinate and ML2[1:2 (metal: ligand) ratio] type. The complexes are coloured and stable in air.