KINETIC-STUDY OF CHARGE-TRANSFER INTERACTION OF SUBSTITUTED PYRIDINESAND SUBSTITUTED 4-STYRYLPYRIDINES WITH P-BROMANIL

Kinetics of charge transfer interaction of various 3- and 4-substitute d pyridines and 4'-substituted 4-styrylpyridines with p-bromanil has b een studied spectrophotometrically in carbon tetrachloride at three di fferent temperatures and thermodynamic parameters have been evaluated. The reaction between pyridine and p-bromanil follows second order kin etics, first order in each reactant. Electron-releasing substituents i n pyridine ring increase the rate of the charge-transfer interaction w hile electron-withdrawing substituents retard it. Good Hammett correla tions have been observed in both the reaction series. The ratio of eff ectiveness of transmission of substitutent effect in styrylpyridine sy stem relative to pyridine system in this reaction is computed to be 0. 167.