Interaction of adenine with dichloro-[1-alkyl-2-(naphthylazo)-imidazole]palladium(II) complexes: kinetic and mechanistic studies

Abstract

Interaction of adenine (A) with dichloro-[1-alkyl-2-(a-naphthylazo)imidazole] palladium(II) [Pd-(a-NaiR)Cl 2 ], 1 and dichloro- 4b, 4c) was studied. The products were characterized by physico-chemical and spectroscopic methods. The reaction kinetics were second order overall, being first order in both the Pd(II) complex and adenine. The effect of adding chloride was consistent with rate-limiting dissociation of chloride from the complex. Thermodynamic parameters were determined from temperature variation experiments. The second-order rate constant k 2 corroborates with the experimental D à H°values, while the negative values of D à S°i ndicate that the reaction proceeds through an associative inner sphere mechanism.