A Triatomic Silicon(0) Cluster Stabilized by a Cyclic Alkyl(amino) Carbene

Reduction of the neutral carbene tetrachlorosilane adduct (cAAC)SiCl4 (cAAC=cyclic alkyl(amino) carbene :C(CMe2)(2)(CH2)N(2,6-iPr(2)C(6)H(3)) with potassium graphite produces stable (cAAC)(3)Si-3, a carbene-stabilized triatomic silicon(0) molecule. The Si-Si bond lengths in (cAAC)(3)Si-3 are 2.399(8), 2.369(8) and 2.398(8)angstrom, which are in the range of Si-Si single bonds. Each trigonal pyramidal silicon atom of the triangular molecule (cAAC)(3)Si-3 possesses a lone pair of electrons. Its bonding, stability, and electron density distributions were studied by quantum chemical calculations.