Kinetic study of the interaction of aquated palladium(II) complexes with purine 5'-nucleoside monophosphates and ribose 5'-monophosphate in aqueous solution. Effects of steric hindrance and phosphate-induced reactivity

The formation reactions of the complexes of Pd(R4en)(H2O)2(super 2+), where R4en = N-substituted ethylenediamine and R = H, Me, Et, with ribose, adenosine, inosine and guanosine 5'-monophosphate were studied as a function of monophosphate concentration and temperature in the pH range of 4 to 5. The nucleotides reacted faster than the nucleosides, indicating the transition state stabilization effect by the monophosphate group. Furthermore, the complex formation rate constants of ribose monophosphate were smaller than those of inosine but larger than those of adenosine.