Convergent Functional Groups. 16. Hydrolysis of Phosphate Triesters by a Novel Cleft. Influence of Binding on Overall Rate Acceleration

The rates of hydrolysis of two activated phosphate triesters, bis(p-nitrophenyl) methyl phosphate 3 and adenosine 5’-0, 0-bis(p-nitrophenyl) phosphate 4 have been studied using two copper-containing catalysts, Cu(Kemp-bpy) 1 and Cu(bpy) 2. The catalytic activities of these two species have been compared within the pH range of 6—9.5. The rates of hydrolysis of both substrates, 3 and 4, have been compared to the uncatalyzed reaction. This rate-enhancement is dependent on pH. In both cases, the monohydroxo H(OH^-)⁺ species is more catalytically active than the diaqua species, H(H₂O)²⁺. The effect of binding on overall rate acceleration was evaluated; the maximum contribution was found to be 44.