Synthesis of novel heterobimetallic copper(I) hydrazone Schiff base complexes: a comparative study on the effect of heterocyclic hydrazides towards interaction with DNA/protein, free radical scavenging and cytotoxicity

Two new copper(I) hydrazone complexes have been synthesised from bivalent copper precursor CuCl(2)(PPh(3))(2)] and ferrocene containing bidentate hydrazone ligands HL(1) (1) or HL(2) (2). Based on the elemental analyses and spectroscopic data, the complexes are best formulated as CuL(1)(PPh(3))(2)] (3) and CuL(2)(PPh(3))(2)] (4) of the monovalent copper ion. Solid state structures of ligand 2 and its corresponding complex 4 were also determined. The DNA/albumin interactions of all the synthesised compounds were investigated using absorption, emission and synchronous fluorescence studies. Further, antioxidant properties of all the compounds have also been checked against ABTS, O(2)(-) and OH radicals. Additionally, the in vitro cytotoxic activity of compounds 1-4 was assessed using tumour (HeLa, A431) and non-tumour (NIH 3T3) cell lines.