Solvent effects on the decomposition of 7-cumyl hydroperoxide in the presence of the phthalocyanines of cobalt and nickel

Abstract

The decomposition of 7-cumyl hydroperoxide catalyzed by cobalt phthalocyanine in the solvent system decalin-3-chlorotoluene (40°C) follows the 2nd order kinetics in the absence of N-(2-naphthyl)aniline and that of the 1st order in the presence of the inhibitor. The effect of composition of the solvent system on the rate constants and on the quotient of the initial rates in presence and in absence of inhibitor and the mechanism of the decomposition are discussed. Nickel phthalocyanine has an inhibiting effect on the decomposition of 7-cumyl hydroperoxide in the solvent systems decalin-1-chloronaphthalene and 3-chlorotoluene-1-chloronaphthalene (120°C). Decomposition starts after addition of N-(2-naphthyl)aniline. After an autocatalytical phase the reaction follows 1st order kinetics. The rate constants depend on the composition of the solvent system. The temperature dependence of the decomposition on 1-chloronaphthalene was determined. The anomalous slope of the Arrhenius plot is discussed.