Chromic acid oxidation of benzhydrols-kinetics and mechanism

摘要: The kinetics of the oxidation benzhydrol (diphenylmethanol) and several its substituents by chromium(VI) oxide in aqueous acetic acid have been studied detail. rate is expressed as v = k3[ArAr'CHOH][CrVI][H+]2 effect ring on gives a p+ value -0.546 (r 0.959) pointing to development an electron-deficient centre transition state. benzhydrol[α-D] proceeds 6.5 times slower than that protio analogue at 55°C. From Arrhenius plots, activation parameters beep evaluated isokinetic relationship has analysed. results are discussed terms mechanism involving rate-determining loss hydride ion from α-carbon benzhydroxy chromate ester.