Two-coordinate, sp-hybridized aluminum and gallium cationic species (2a and 2b) were synthesized by the methyl group abstraction from the t-BU2MeSi group by Et3Si+ followed by 1,2-silyl group migration from group 13 element to the cationic silicon center. X-ray crystal structure analyses confirmed these species to be free cations stabilized by hyperconjugation with a neighboring Si-Si sigma bond.