Synthesis, characterization and antitumour studies of metal chelates of N1-isonicotinoyl-3-methyl-4-(p-hydroxybenzilidene)-2-pyrazolin-5-one

The cobalt(II), nickel(II) and copper(II) complexes of N1-isonicotinoyl-3-methyl-4-(p-hydroxybenzilidene)-2-pyrazolin+ ++-5-one (IMHBP) with different counter anions have been prepared and characterized. An octahedral geometry has been assigned to the cobalt(II) and nickel(II) complexes and a square-planar structure to the copper(II) complexes. IMHBP acts as a neutral bidentate ligand in all these complexes by coordinating through the oxygen atoms of the amide group and carbonyl at position-5. The other coordination sites are satisfied by anions alone or anions and water molecules. The ligand and the complexes were screened for their possible antitumour activity. The copper(II) complexes are appreciably active in reducing mice tumours.