The Insertion of E^II and E^IV Chlorides (E=Si, Ge) into the Si-Si Bond of Disilylene

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.