Synthesis and Reactivity of Bidentate N‐Heterocyclic Carbene‐Phosphinidene Supported Si(IV) Dicationic Complexes

Abstract Herein, we report the synthesis and isolation of Si(IV) dications stabilized by a bidentate N ‐heterocyclic carbene‐phosphinidene (NHCP). Treatment of the bis(NHCP) with Si(IV) bis(triflate) R 2 Si(OTf) 2 (with R=H, Ph) resulted in the instant formation of Si(IV) dicationic complexes [ 2 a ] and [ 2 b ] featuring a tetracoordinated silicon centre. The dications show expected high Lewis acidity. The bis(NHCP)‐stabilized parent silyl dication 2a (SiH 2 2+ ) presents the first isolable example of a parent SiH 2 dication. In addition, dication [ 2 a ] is able to react with diphenylketene by insertion into the Si−P bond.