SiC₂ Silagraphene and Its One-Dimensional Derivatives: Where Planar Tetracoordinate Silicon Happens

The periodic systems containing planar tetracoordinate silicon (ptSi), SiC(2) silagraphene, nanotubes, and nanoribbons, were predicted by means of density functional theory (DFT) computations. In SiC(2) silagraphene, each silicon atom is bonded by four carbon atoms in a pure plane, representing the first anti-van't Hoff/Lebel species in the Si-containing extended system. SiC(2) nanotubes, rolled up by the SiC(2) silagraphene, exhibit excellent elastic properties. All these ptSi-containing nanomaterials are metallic, regardless of the chirality, tube diameter, or ribbon width. The high stabilities of these systems strongly suggest the feasibility for their experimental realizations.