Kinetics and equilibria for the axial ligation of bromomethyl (aqua)cobaloxime with pyridines - Isolation characterization and DNA binding

Journal of Chemical Sciences

K Ashwini Kumar¹  Penumaka Nagababu¹  Kotha Laxma Reddy¹  S Satyanarayana¹  A Panasa Reddy¹  N Ravi Kumar Reddy¹ 

[1] Department of Chemistry, Osmania University, Hyderabad 500 007$$

关键词: Cobaloximes;    kinetics and equilibria;    DNA-binding.;   

DOI  :  

来源: Indian Academy of Sciences

【 摘 要 】

The kinetics and equilibria for the axial ligation of pyridine and substituted pyridines to bromomethyl(aqua)cobaloxime have been measured spectrophotometrically in aqueous solutions of ionic strength 1.0 M (KC1) at 25°C as a function of 𝑝H. The binding constants and rate of formation increase in the order 4-NH2Py 4-EtPy > 4-MePy > Py > 2-NH2Py > 2-EtPy. The data have been interpreted based on the basicity of the ligand, 𝜋-back bonding from Co(III) → L and hard and soft interactions. The rate of substitution of H2O varies with the pKa of the incoming ligand, thus establishing the existence of nucleophilic participation of the ligand in the transition state. We have investigated the DNA binding of bromomethyl(aqua)cobaloxime with DNA. Bromomethyl(ligand)cobaloximes were isolated and characterized by elemental analysis, IR and NMR (1H, 13C) spectra.

【 授权许可】

Unknown