Reactions of acyl phosphates. Base hydrolysis of [Co(NH₃)₅OPO₃COCH₃]⁺ and the metal hydroxide promoted hydrolysis of acetyl phenyl phosphate

Abstract

Tracer ¹⁸O studies have established that base hydrolysis of coordinated acetyl phosphate in [(NH₃)₅Co-OPO₃COCH₃]⁺ (k_OH 0.53 mol^-1 dm³ s^-1, 25°C, I 1.0 NaClO₄) proceeds with exclusive carbon-oxygen bond fission. The hydrolysis of acetyl phenyl phosphate monoanion is significantly catalysed by the exchange-inert hydroxo complex [(NH₃)₅Co-OH]²⁺ (k_MOH 2.9 × 10^-2 mol^-1 dm³ s^-1, 25°) which operates through a nucleophilic pathway involving attack at carbonyl carbon.