AB-INITIO STUDY ON THE REACTION OF TRIMETHYLGALLIUM WITH HYDROGEN MOLECULE

The reaction of trimethylgallium (Ga(CH3)3, TMG) with H-2 has been investigated using ab initio molecular orbital calculations. It has been shown that the activation energy of the reaction TMG + H-2 --> GaH(CH3)2 + CH4 is 34.2 kcal/mol, while the dissociation energy of the radial decomposition TMG --> Ga(CH3)2 + CH3 is 76.9 kcal/mol. This means that TMG decomposition is dominated by hydrogenolysis under the conditions where collisions between TMG and H-2 are sufficiently frequent. This result explains the experimental result that the decomposition of TMG was enhanced by increasing the H-2 pressure.