[[(Me3Si)2CH]2iPrSi(NHC)Si═Si(Me)SiiPr[CH(SiMe3)2]2]+: A Molecule with Disilenyl Cation Character

Reaction of the disilyne–NHC complex 1 [RLSi═SiR: (R = SiiPr[CH(SiMe3)2]2, L = NHC)] with MeOTf gave the cation 2 [RLSi═SiRMe]+, which is the first example of a base-stabilized heavy group 14 element analogue with vinyl cation character. Cation 2 has been fully characterized by multinuclear NMR spectroscopy and X-ray diffraction analysis. The molecular structure indicates that there are significant contributions from the NHC-stabilized cationic resonance structure 2A, the disilene-like structure 2B, and even some contribution from the silylene-like structure 2C.