title: Solvolyses of benzoyl chlorides in weakly nucleophilic media.
abstract: Rate constants and activations parameters are reported for solvolyses of p-Z-substituted benzoyl chlorides (1, Z = OMe, Me, H, and Cl) in 97% w/w hexafluoroisopropanol-water (97H). Additional kinetic data are reported for solvolyses in acetic and formic acids. Plots of log k vs. σ(p) in 97H are consistent with previous research showing that a cationic reaction channel is dominant, even for solvolyses of 1, Z = NO(2). A benzoyl cation intermediate was trapped by Friedel-Crafts reaction with 1,3,5-trimethoxybenzene in hexafluoroisopropanol. The results are explained by an S(N)2-S(N)1 spectrum of mechanisms with variations in nucleophilic solvent assistance. Ab initio calculations of heterolytic bond dissociation energies of various chloro- and fluoro-substituted and other benzoyl chlorides are correlated with log k for solvolyses.
authors.affiliation: Chemistry Unit, Grove Building, School of Medicine, Swansea University, Swansea SA2 8PP, Wales, UK; E-Mail:  carl.harris1@googlemail.com.
authors.forename: Thomas William
authors.initials: TW
authors.lastname: Bentley
authors.forename: Haldon Carl
authors.initials: HC
authors.lastname: Harris
mesh_terms: D001565:Benzoates / Q000737:chemistry*; D007700:Kinetics; D012997:Solvents / Q000737:chemistry*
chemical_list: D001565:Benzoates; D012997:Solvents; C013409:benzoyl chloride