Tuning Philicity of Dichlorosilylene: Nucleophilic Behavior of the Dichlorosilylene–NHC Complex Cl2Si–IPr

Novel unsaturated four-membered ring disilene, 3,3-dichloro-1,2,4,4-tetrakis­[di-tert-butyl­(methyl)­silyl]-1Δ-1,2,3,4-trisilagermetene, was synthesized by the ring expansion reaction of the three-membered ring 1-disilagermirene with the silylene–NHC complex Cl2Si–IPr. The mechanism of the unexpected formation of this compound was verified by high-level density functional theory computations, which revealed nSi:(HOMO)–πSiSi(LUMO)* as the dominant orbital interaction.