Chalcogen-atom transfer and exchange reactions of NHC-stabilized heavier silaacylium ions

Abstract

Heavier analogues of silaacylium ions 2–4 ([m-TerSiE(NHC)₂]Cl; m-Ter = 2,6-Mes₂C₆H₃; Mes = 2,4,6-Me₃C₆H₂; 2 (E = S), 3 (E = Se), 4 (E = Te)) were synthesized by the reaction of the NHC-stabilized silyliumylidene cation 1 with elemental chalcogens. Fascinating regeneration of 1 from the reaction of 2–4 with AuI was achieved, as successful recovery of a parent Si(II) species from a silachalcogen Si(IV) compound. Furthermore, unique chalcogen exchange reactions from 4 → 3 → 2 were observed in line with the calculated silicon–chalcogen bond energies.