Phosphine-Stabilized Germasilenylidene: Source for a Silicon-Atom Transfer.

A phosphine-stabilized germasilenylidene is synthesized following the pathway of SiCl4 oxidative addition at a germylene-phosphine Lewis pair. Low-temperature reduction using {(MesNacnac)Mg}2 resulted in a chlorosilylene intermediate and finally a molecule exhibiting a Ge═Si: motif. Inside the chelating phosphine-germylene, a low-valent silicon atom is stabilized and was transferred to diazabutadiene to give N-heterocyclic silylenes. Because of the high reactivity of the phosphine-stabilized germasilenylidene, a reaction of two Ge═Si: units was found to yield a Si2Ge2-ring molecule exhibiting a germasilene substituted with a silylene.