Studies of the pyrolysis of diethylzinc by the toluene carrier method and of the reaction of ethyl radicals with toluene

Abstract

The thermal decomposition of diethylzinc in a toluene carrier system has been studied over the temperature range of 669 to 762 K, and percent decomposition of 3.8 to 97.2%. The decomposition occurs by a two step mechanism, the second step rapidly following the first,[Formula: see text]The overall progress of the reaction was followed by determination of the residual diethylzinc by hydrolysis followed by analysis for zinc by atomic absorption. In selected runs two additional methods were used: (i) measurement and analysis of the gas evolved during the hydrolysis and (ii) full analysis of all pyrolysis products involving the C 2 H 5 group.In the absence of zinc oxide the decomposition is essentially homogeneous and[Formula: see text]or −205 000/19.15T if the activation energy is expressed in joules rather than calories. The presence of zinc oxide causes marked catalysis of the overall decomposition but does not appear to affect reaction 3 or reaction 6.[Formula: see text][Formula: see text]Reaction 6 is in a strongly pressure dependent region and is based on very limited data.