STABILITY OF SUBSTITUTED LEWIS ADDUCTS OF SUBSTITUTED GALLANES AND ARSINES

The Lewis acid/base adducts formed by the reaction of gallane, chlorogallane, trichlorogallane, fluorogallane, trifluorogallane, methylgallane, and dimethylgallane with arsine have been studied using molecular orbital methods using basis sets derived from those published by Huzinaga. A similar study was performed which employed methyl-substituted arsines. The calculated dissociation energies of these adducts were structurally dependent and varied between 10 and 20 kcal mol-1 at the MP4(SDTQ) level (HF geometries). For the adducts of chlorogallane and fluorogallane with arsine, evidence is found for bonding contributions between the halogen atom and the arsenic atom. Except for these cases, Ga...As bond lengths and symmetric stretching frequencies were simply related to the acid/base characteristics of the constituent gallanes and arsines. Since it is known that adducts of substituted gallanes and arsines lead to epitaxial growth (MBE) and to thin films (MOCVD) with desirable properties, the adducts reported here may also find practical applications.