Lima, F. S.
Cuccovia, I. M.
Total Authors: 3
 Univ Sao Paulo, Inst Quim, Dept Bioquim, BR-05508900 Sao Paulo - Brazil
Total Affiliations: 1
JOURNAL OF PHYSICAL ORGANIC CHEMISTRY;
Web of Science Citations:
The rate of solvolysis of p-nitrophenyl phosphate (PNPP) dianion in DMSO/water strongly decreases by increasing water concentration. Addition of linear alcohols (methanol, propanol, butanol, pentanol, and hexanol) at constant DMSO/water molar ratio produced an even sharper rate decrease. Alkyl phosphate formation, resulting from PNPP solvolysis in ternary DMSO/water/alcohol mixtures, increased with alcohol concentration and was essentially temperature independent. Methanol and hexanol were the poorest nucleophiles under all conditions. Activation energies and enthalpies for solvolysis in ternary mixtures were similar and entropies varied with alcohol concentration. Taken together these results can be best interpreted in terms of a dissociative mechanism with the intervention of metaphosphate. Copyright (C) 2011 John Wiley \& Sons, Ltd. (AU)