Radicals, Anions, and Cations of Silicon and Silylenes

Since the isolation of the stable examples of disilene and silene in 1981, the low-coordinate silicon chemistry has flourished progressively. Silicon-based functional groups have been investigated intensively and the low-coordinate silicon compounds are now beyond being considered as laboratory curiosities. Several stable silyl radicals are isolated and structurally characterized and already being tested for potential applications. Heteroleptic multiple-bond main-group compounds with silicon find ever-increasing interest because of unique electronic properties. Silyl cations and silylenes are used for small-molecule activation due to their highly reactive nature. In addition, silylene and bis(silylene) ligands have proved promising ligands toward transition metals and their application as catalysts in several organic reactions have also being investigated. This chapter highlights the important progress made in the field of low-coordinate silicon compounds in the previous decade. The synthetic techniques elaborated in this chapter focus on their facile access.