Synthesis and Characterization of Substituted Phosphasilenes and its Rare Homologue Stibasilene >Si=Sb−

Abstract

AbstractHerein we report the reduction of R‐EX2 (E=P, Sb) with two equivalents of KC8 in the presence of silylene (LSiR; L=PhC(NtBu)2) to give Trip‐P=SiL(C6H4PPh2) (1), TerPh−P=(tBu)SiL (2) and TerPh−Sb=(tBu)SiL (3). The last (3) belongs to a new class of heavier analogues of Schiff bases (>C=N−), containing a formal >Si=Sb− double bond. The theoretical calculations suggest that lone pairs on the dicoordinated group‐15 centers are stabilized by hyperconjugative interactions resulting in pseudo‐Si−P/Si−Sb multiple bonds which are highly reactive as indicated by the high first and second proton affinities.