Kinetic study of triphenylphosphine addition to para‐benzoquinone

Abstract

Kinetics of the addition reaction of triphenylphosphine to para-benzoquinone in 1,2-dichloroethane as solvent was studied. Initial rate method was used to determine the order of the reaction with respect to the reactants. Pseudo-first-order method was also used to calculate the rate constant. This reaction was monitored by UV-vis spectrophotometry at 520 nm by variable time method. On the basis of the obtained results, the Arrhenius equation of this reaction was obtained:The activation parameters, E a , H # , G # , and S # at 300 K were 5. 701, 6.294, 19.958 kcal mol −1 and −45.853 cal mol −1 K −1 , respectively. This reaction is first and second order with respect to triphenylphosphine and para-benzoquinone, respectively. C

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

“…Recently, we have also reported a kinetic investigation of the addition reaction of triphenylphosphine to para-benzoquinone in 1,2-dichloroethane as solvent [11], where the obtained data revealed that the reaction is of first order with respect to triphenylphosphine and of second order with respect to para-benzoquinone.…”

“…Based on the rate equation and the results obtained with the addition reaction of triphenylphosphine with the parent molecule (para-benzoquinone) [11], the following mechanism could be suggested. In the first step, the triphenylphosphine phosphorus attacks the carbon of the carbonyl group of the paranaphthoquinone and produces the intermediate I (see Scheme 2).…”