Reaction of the ground-state Al(2P) with silane: Examination of the potential energy surfaces for complexation, insertion and interconversion

A route of formation of SiH3AlH radical via insertion of the ground-state Al(2P) into SiH4 and subsequent rearrangements to various primary insertion product isomers including more stable SiH2AlH2 radical are predicted from the ab initio single-reference CCSD(T) and multi-reference MRMP2 calculations. For the insertion reaction, the lowest energy doublet (2A′) potential energy surface is studied within Cs symmetry. Special attention is paid to the weakly bound Al⋯SiH4 complexes formed in the initial stage of the reaction. The results presented are of relevance to recent matrix studies on reactivity of the Al/SiH4 system.