Abstract: The rates of hydrolysis of two activated phosphate triesters, bis (p-nitrophenyl) methyl phosphate 3 and adenosine 5'-O, O-bis@-nitrophenyl) phosphate 4 have been studied using two copper-containing catalysts, Cu (Kempbpy) 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. ...