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

Abstract

Five coordinated novel complexes of ${\text{Cu}}^{\text{II}}$ and ${\text{Ni}}^{\text{II}}$ have been synthesized from benzil and 1,3- diaminopropane-${\text{Cu}}^{\text{II}}$/${\text{Ni}}^{\text{II}}$ 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 ${\text{C}}_{25}{\text{H}}_{36}{\text{N}}_{\text{5}}{\text{O}}_2\text{CuCl}$ 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 ${\text{K}}_{\text{obs}}$ values have been calculated under pseudo-first order conditions. The redox behaviour of complex ${\text{C}}_{25}{\text{H}}_{36}{\text{N}}_{\text{5}}{\text{O}}_2\text{CuCl}$ 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 ${\text{Cu}}^{\text{II}}$/${\text{Cu}}^{\text{I}}$ redox couple with ${\text{E}}_{1/2}$ values of -0.377 and -0.237 V respectively at a scan rate of 0.1V${\text{s}}^{\text{-}1}$ .On interaction with calf thymus DNA, the complex ${\text{C}}_{25}{\text{H}}_{36}{\text{N}}_{\text{5}}{\text{O}}_2\text{CuCl}$ exhibits shifts in both ${\text{E}}_{\text{p}}$ as well as in ${\text{E}}_{1/2}$ values, indicating strong binding of the complex to the calf thymus DNA.

Full Text

The Full Text of this article is available as a PDF (879.6 KB).