Quantum-chemical calculation of the mechanism of gas-phase hydrolysis of benzenesulfonyl chloride

The potential energy surface of gas-phase hydrolysis of benzenesulfonyl chl oride was calculated by PM3 quantum-chemical method. The structural and ene rgy parameters were calculated for all the intermediates and transition sta tes; activation parameters and the thermodynamic functions of the reaction were determined. The-axial orientation of the nucleophilic attack is prefer red when the reactive center is attacked by the water molecule occurring at tile axis of tile C-S bond from the sulfonyl group. Gas-phase hydrolysis o f benzenesulfonyl chloride is an exothermic process involving formation of all unstable live-coordinate intermediate. The calculated apparent rate con stants and activation parameters of the process are compared with the publi shed data on hydrolysis of benzenesulfonyl chloride in water and aqueous-or ganic solvents.