Synthesis, Characterization and DNA Binding Studies of Some Hydrazide Derivatives Schiff Base Metal Complexes of Mn(II), Co(II/III), Ni(II), Cu(II) and Zn(II) Metal Ions

Abstract

Eighteen metal complexes were synthesized by using four different Schiff base ligands, (1E)-1-((6-methyl-4-oxo-4H-chromen-3-yl)methylene)carbohydrazide (L₁), 6-[2-(salicylidene)hydrazinyl]-N′-(salicylidene)nicotinohydrazide (HL₁), 6-hydrazinyl-N′-(6-methyl-4-oxo-4H-chromen-3-yl-methylene)nicotinohydrazide (HL₃) and (E)-6-hydrazinyl-N′-(1-(2,3-dihydro-1,3-dioxo-1H-inden-2-yl)-ethylidene)pyridine-3-carbohydrazide (L₄). Characterization of the metal complexes were carried out by using various physico-chemical techniques. Complexes 1, 3, 4, 6, 11, 14, 15, 16, 17 and 18 have been found octahedral structures while the metal complexes 2, 5, 8, 10 and 13 have tetrahedral structures. And, complexes 7, 9 and 12 have square planar structures. Thermal study has revealed the presence of lattice and coordinated water molecules in the complexes. From powder X-ray diffraction study, it was suggested that a monoclinic system for complexes 2 and 14 while a triclinic system for the complexes 3, 4, 5, 9, 11, 13 and 15. The interaction of the ligands and their metal complexes with calf thymus DNA (CT-DNA) has been studied by electronic absorption, cyclic voltammetry and viscosity methods.