Understanding of binding of a bis(imido)-bridged dinuclear cobalt(III) complex with Calf thymus DNA

The interaction of a bis(imido)-bridged dinuclear cobalt(III) complex with Calf thymus DNA (CT-DNA) was investigated by the absorption and emission spectral studies, and viscosity measurements. Absorption spectral studies showed only moderate hypochromism with negligible red-shift, and the intrinsic binding constant value of 1.7 x 10(4) M-1 justifies that the present complex interact with CT-DNA in the groove region. The Stern-Volmer quenching constant (K-SV) value of 3.66 x 10(3) M-1 obtained from the ethidium bromide (EB) displacement assays supports the above fact. The groove binding mode of the complex is further established by the viscosity measurements.