Aromaticity of group 14 organometallics: Experimental aspects

The long story of aromatic compounds has extended over almost two centuries, since the discovery by Faraday of "bicarburet of hydrogen", or C6H6, now called benzene. Since then, the chemistry of aromatic compounds has been developed extensively; this is reflected in the synthesis of novel classes of aromatic derivatives including charged species, nonclassical (Möbius, three-dimensional, homo-, metalla-) aromatics, and fullerenes. The theory of aromaticity has also undergone a spectacular evolution since the first definition of aromaticity by Hückel; the classification of aromaticity now requires the consideration of versatile criteria: energetic, structural, magnetic, among others. In this Review, we discuss the current state of affairs in the chemistry of aromatic compounds of the heavier Group 14 elements, the latest experimental achievements, as well as future prospects in the field. © 2007 Wiley-VCH Verlag GmbH & Co. KGaA.