The Insertion of EII and EIV Chlorides (E=Si, Ge) into the Si-Si Bond of Disilylene.

ABSTRACT

Reactions of silicon and germanium dichlorides L⋅ECl2 (E=Si, L=IPr; E=Ge, L=dioxane) with the phosphinoamidinato-supported disilylene ({κ2 (N,P)-NNP}Si)2 resulted in formal tetrylene insertions into the Si-Si bond. In the case of the reaction with silylene, two products were isolated. The first product ({κ2 (N,P)-NNP}Si)2 SiCl2 , is the formal product of direct SiCl2 insertion into the Si-Si bond of ({κ2 (N,P)-NNP}Si)2 and thus features two separated silylamido silylene centers. Over time, migration of the SiCl2 group to a lateral position afforded the second product, the disilylene {κ2 (Si,P)-SiCl2 NNP}Si-Si{κ2 (N,P)-NNP}. In contrast, insertion of GeCl2 resulted only in the isolation of the germanium analogue of {κ2 (Si,P)-SiCl2 NNP}Si-Si{κ2 (N,P)-NNP}, containing a Ge atom in the central position namely, compound {κ2 (Si,P)-SiCl2 NNP}Ge-Si{κ2 (N,P)-NNP}, which is a rare example of a silylene-germylene. Finally, reaction of disilylene ({κ2 (N,P)-NNP}Si)2 with SiCl4 and SiHCl3 led to the formation of the new bis(silyl)silylene, ({NNP}SiCl2 )2 Si. All four new products from these insertion reactions have been characterized by multinuclear NMR and single-crystal X-ray diffraction studies.