Synthesis of New Five Coordinated Copper(II) and Nickel(II) Complexes of L-Valine and Kinetic Study of Copper(II) with Calf Thymus DNA

Five coordinated novel complexes of CuII and NiII have been synthesized from benzil and 1,3- diaminopropane-CuII/NiII complex and characterized by elemental analysis, i.r., n.m.r., e.p.r, molar conductance and u.v-vis, spectroscopy. The complexes are ionic in nature and exhibit pentaeoordinated geometry around the metal ion. The reaction kinetics of C25H36N5O2CuCl with calf thymus DNA was studied by u.v-vis, spectroscopy in aqueous medium. The complex after interaction with calf thymus DNA shows shift in the absorption spectrum and hypochromicity indicating an intercalative binding mode. The Kobs values have been calculated under pseudo-first order conditions. The redox behaviour of complex C25H36N5O2CuCl in the presence and in the absence of calf thymus DNA in the aqueous solution has been investigated by cyclic voltammetry. The cyclic voitammogram exhibits one quasi-reversible redox wave corresponding to CuII/CuI redox couple with E1/2 values of -0.377 and -0.237 V respectively at a scan rate of 0.1Vs-1 .On interaction with calf thymus DNA, the complex C25H36N5O2CuCl exhibits shifts in both Ep as well as in E1/2 values, indicating strong binding of the complex to the calf thymus DNA.