Planar Tetras-, Penta-, Hexa-, Hepta-, and Octacoordinate Silicons: A Universal Structural Pattern.

A universal structural pattern has been presented at density function theory level to incorporate planner tetra-, penta-, hexa-, hepta-, and octacoordinate silicons in C2vBnE2Si series (E = Ch, BH, or Si; n = 2-5) and D8hB8Si. The equivalence in valence electron counts and one-to-one correspondence of the delocalized π and σ valence orbitals with small boron clusters strongly support the optimized structures containing planar coordinate silicons. Planar BnE2Si series are predicted to be aromatic in nature, and the photoelectron experiments. This structural pattern can be applied to form other planner coordinate nonmetals including Ge, P, As, Al, and Ga and needs to be confirmed in experiments to open a new branch of chemistry on planar coordinate main group elements. [ABSTRACT FROM AUTHOR]