A Neutral Silicon/Phosphorus Frustrated Lewis Pair

Frustrated Lewis pairs (FLPs) have a great potential for activation of small molecules. Most known FLP systems are based on boron or aluminum atoms as acid functions, few on zinc, and only two on boron‐isoelectronic silicenium cation systems. The first FLP system based on a neutral silane, (C2F5)3SiCH2P(tBu)2 (1), was prepared from (C2F5)3SiCl with C2F5 groups of very high electronegativity and LiCH2P(tBu)2. 1 is capable of cleaving hydrogen, and adds CO2 and SO2. Hydrogen splitting was confirmed by H/D scrambling reactions. The structures of 1, its CO2 and SO2 adducts, and a decomposition product with CO2 were elucidated by X‐ray diffraction. Yes, Si can! The first neutral frustrated Lewis pair system based on silicon, (C2F5)3SiCH2P(tBu)2, was prepared from (C2F5)3SiCl and LiCH2P(tBu)2. This species binds CO2 and SO2 between its Lewis acidic and basic sites and cleaves dihydrogen (see structure with CO2: C gray, F green, O red, P magenta, Si orange).