The reaction of disilyne 1 with 1,3,4,5-tetramethylimidazol-2-ylidene (an N-heterocyclic carbene, NHC) produced the disilyne-NHC complex 2, RLSi═SiR: (R = Si(i)Pr[CH(SiMe(3))(2)](2), L = NHC), with a trans geometry of the Si═Si moiety and lone-pair electrons residing on one of the double-bonded Si atoms. Upon complexation of 2 with ZnCl(2), the disilyne-NHC-ZnCl(2) complex 3 was produced, in which the Si═Si bond adopted the cis geometry.

In an exploration of six coordination and hypervalence in carbon compounds, steric constraints have been employed to bring four ether O atoms in close proximity to an allenic carbon atom. The dimethylated dication 2 is confirmed to have hexacoordinate carbon by experimental charge density analysis and DFT calculations and is arguably hypervalent.

cyclotetrasilenylium (3 + ), a silylium ion with an allylic cation character, was synthesized by the reaction of tetrakis(di-tertbutylmethylsilyl)disilene with [Et 3 Si(benzene)] + • TPFPBin toluene. The NMR spectral data and X-ray structure of 3 + • TPFPBshow that it is a free silylium ion with an allylic cation structure.