The kinetics of oxidation of benzaldehyde. II. The kinetics of the uncatalyzed reaction in solution

Abstract

The initial rate of oxidation of benzaldehyde in benzene solution in the absence of catalysts and inhibitors is given by the relation (-d[O 2 ]/d t ) = ([ R H] 2 [O 2 ])/( b [ R H] 2 + c [O 2 ]). The reciprocals of the constants b and c vary with temperature according to the Arrhenius equation, the corresponding activation energies being 6.0 ± 0.5 and 17.5 ± 1.0 kcal/mole respectively. The difficulty of interpreting the relation in terms of the mechanism proposed by Bolland & Gee (1946) for photochemical and peroxide catalyzed oxidations is pointed out. It is suggested that this kinetic behaviour is of widespread occurrence in uncatalyzed oxidations.