Premium
Isergonic relationship in the acid‐catalyzed hydrolysis of carboxylic esters with hydrogen‐bonding capability
Author(s) -
MataSegreda Julio F.
Publication year - 2004
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.779
Subject(s) - chemistry , enthalpy , hydrogen bond , catalysis , hydrolysis , solvent , alkyl , hydrogen , carboxylic acid , organic chemistry , organic solvent , medicinal chemistry , molecule , thermodynamics , chemical engineering , physics , engineering
The average value of the enthalpies of activation for the acid‐catalyzed hydrolyses of ethyl 2‐hydroxypropanoate and five acetate esters with hydrogen bonding capability is 57±7 kJ mol −1 ( p = 0.05). This value is 11 kJ mol −1 lower than the mean observed for primary and secondary alkyl acetates and ethyl alkanoates, measured in water and in mixtures of water with organic solvent with high water content. The difference is attributed to tighter transition‐state complex hydration via hydrogen bonding, relative to reactant ester species. Enthalpy–entropy compensation with an isokinetic temperature of 346 K was found to be valid at p <0.05, a value typical for solvent‐mediated kinetic effects. Copyright © 2004 John Wiley & Sons, Ltd.