Polyanionic hexagons: X 6n- (X = Si, Ge)

Abstract

The paper reviews the polyanionic hexagons of silicon and germanium, focusing on aromaticity. The chair-like structures of hexasila- and hexagermabenzene are similar to a nonaromatic cyclohexane (CH 2) 6 and dissimilar to aromatic D 6h-symmetric benzene (CH) 6, although silicon and germanium are in the same group of the periodic table as carbon. Recently, six-membered silicon and germanium rings with extra electrons instead of conventional substituents, such as alkyl, aryl, etc., were calculated by us to have D 6h symmetry and to be aromatic. We summarize here our main findings and the background needed to reach them, and propose a synthetically accessible molecule. © 2010 by the authors; licensee MDPI, Basel, Switzerland.