KINETICS OF THE LIQUID-PHASE OXIDATION OF DIPHENYLMETHANE AT MODERATETEMPERATURES

The relative and absolute parameters for the oxidation of diphenylmeth ane RH(2) to HROOH in the solvents PhH, PhCl, PhBr, MeCN, Me(3)COH, an d CCl4 are measured by monitoring oxygen consumption and chemiluminesc ence at 30-60 degrees C. The rate constant for the chain termination k (6), which is independent of the solvent nature and decreases with tem perature, is high and equals (1.5-3) x 10(8) l mol(-1) s(-1). The rate constants for the chain propagation k(2), and for the reaction of HRO O(.) with chroman C-1 as an antioxidant k(7), are also independent of the solvent nature. Only polar MeCN and Me(3)COH block the antioxidant , thus increasing the activation energy and decreasing k(7).