Canadian Science Publishing, Canadian Journal of Chemistry, 4(93), p. 422-427, 2015
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The hydrolytic reactivity of simple phosphate diesters with very good leaving groups is known to be practically independent of the nonleaving group at 100 °C. Calculations on the (too slow to measure) hydrolysis at 25 °C of a series of p-nitrophenyl diesters ROPO2––OpNP with a wide range of nonleaving group OR indicate a small but significant effect at the lower temperature, making the R = methyl ester the most reactive. This is in the opposite sense to the much larger effect observed for the reactions of triesters and consistent with a reaction driven primarily by leaving group departure. The calculations use a continuum model with up to four discrete water molecules: two or three waters give the best results.