Trimethyl gallium, indium and thallium

Studies of the pyrolysis of these three alkyls may conveniently be discussed in a combined section. The decompositions were carried out in a conventional toluene carrier flow system using contact times of 1-2 sec120,122,123. The conditions used satisfy both plug flow and thermal equilibrium requirements68,69. Toluene to alkyl ratios greater than 50 in the trimethyl gallium system and greater than 200 in the trimethyl indium and thallium studies were required to obtain first-order dependence in terms of the alkyl concentration. Under these conditions methane and ethane are produced by the reactions 

Some 3-4 % of the CH4 is formed by abstraction of ring hydrogen atoms, but this is of no consequence in the present discussion. Values of klfk2i can be calculated using the equation 

The observed breaks may be explained if it is assumed that the following general mechanism applies 

When trimethyl thallium is used123 the Arrhenius plot of k kj is linear over 

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