Investigation of kinetic and mechanism of triphenylphosphine addition to para‐naphthoquinone

Abstract

This work reports the results of a kinetic and mechanistic investigations of the addition reaction of triphenylphosphine to para-naphtoquinone in 1,2-dichloromethane as solvent. The order of reaction with respect to the reactants was determined using initial rate method, and the rate constant was obtained on the basis of pseudo-first-order method. Variable time method using Uv-Vis spectrophotometry (at 400 nm) was utilized for monitoring this addition reaction, for which the following Arrhenius equation was obtained: log k = 9.14 − 13.63 2.303RTThe resulting activation parameters E a , H # , G # , and S # at 300 K were 13.63, 14.42, 18.75 kcal mol −1 , and −14.54 cal mol −1 K −1 , respectively. The results suggest that the reaction is first order with respect to both triphenylphosphine and para-naphthoquinone.