The Elusive Silyliumylidene [ClSi:]+ and Silathionium [ClSiS]+ Cations Stabilized by Bis(Iminophosphorane) Chelate Ligand

Abstract

Donor–acceptor trumps: The chlorosilyliumylidene salt 2 with a three-coordinate silicon(II) atom is accessible through ligand exchange between NHCSiCl2 and the electron-rich bis(ylide) ligand 1. The cation in 2 represents a donor-stabilized form of the elusive [ClSi:] cation and could be fully characterized, including X-ray diffraction analysis. Oxidation of 2 with elemental sulfur furnished 3 as the sole product.