Abstract
The second‐order rate constants of the alkaline hydrolysis at different temperatures of a number of nitrophenyl phosphorus esters and the values of the quantities ΔH* and ΔS* at 25°C are reported. The effect of structural changes on the values of ΔH* and ΔS* are considered and are compared with similar changes in other nucleophilic substitution reactions, on both phosphorus and carbon atoms.