ISSN 1017-2548(Print)
ISSN 2234-8530(Online)
Volume 31, Number 5
JKCSEZ 31(5)
October 20, 1987 

Rates of the reaction for p-nitro benzyl chloride, benzyl chloride and p-methyl benzyl chloride with pyridine in methanol solvent have been measured by an electric conductivity method at 40℃ and 50℃ under various pressures (1∼2000bar). Pseudo first-order rate constants and second-order rate constants were determined. Rates of these reactions were increased in the order p-NO2 < p-H < p-CH3 and increased with temperature, pressure and concentration of pyridine. From those rate constants, the activation parameters were evaluated. The activation volume and the activation compressibility coefficient are both negative values, but the activation enthalpy is positive and the activation entropy is large negative value. From the evaluation of the ground state and transition state which was resulted from substituents and pressure, it was found that this reaction proceeds through SN2 reaction, and SN2 fashion is slightly disappeared as pressure increases.