ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 37, Number 6
JKCSEZ 37(6)
December 20, 1993 

The reaction rates of para-substituted benzoyl chlorides with substituted pyridines have been measured employing the conductometry method in acetonitrile, and pseudo-first order and second order rate constants are determined at various pressures and temperatures. The activation parameters (△V≠, △β≠, △H≠, △S≠, △G≠) and the Hammett ρ-values are determined from the values of rate constants. The values of △V≠, △β≠ and △S≠ are all negative. The Hammett ρ-values are negative for the nucleophile (ρX), and positive for the substrate (ρY) over the pressure range studied. The results of kinetic studies for pressure and substituent show that these reactions proceed in typical SN2 reaction mechanism and in bond formation favored with elevating pressure.