Kinetics of the gas-phase thermal decomposition of methylcyclopropanemethanol

Kinetics of the gas phase thermal decomposition of metbylcyclopropanemethanol (MCM) was studied over the temperature range 640-720 K and pressure between 4-16 torr using static system. Initial runs carried out in aged unpacked reaction vessel yield small amount of expected isomerization products i.e. cis and trans-2-methyl-l-buten-4-ol and 2-methy-2-buten-4-ol. Formed simultaneously with the isomeric products were large amounts of other products that have clearly formed as the result of fragmentation reactions. In view of the complexities due to rapid secondary decomposition of initial reaction products it was decided only to determine the overall rate of loss of methylcyclopropane methanol; this proved to be a first order, homogenous, unaffected by the addition of nitric acid and probably unimolecular. First order rate constants were determined at six temperatures using 15 torr initial reactant. The Arrhenius parameters are given in the rate equation [GRAPHICS] The results are compared with those for other cyclopropanes and the mechanism considered likely to invove a biradical transition state.