Strained dehydrobenzoannulenes

Dehydrobenzoannulenes (DBAs) have been attracting a great deal of interest as a result of their potential applications as optoelectronic materials, precursors of new forms of carbon materials, and as building blocks for hitherto-unknown 2D carbon networks consisting of sp and sp(2) carbon atoms. Among the DBAs, those with substantial strain due to bond-angle deformation at the triple bonds exhibit greater potential as electronic communication units and precursors of new polycyclic, conjugated ring systems owing to their high reactivity towards carbon-carbon bond-forming reactions. It is also of interest to see how the deformation of triple bonds affects the cyclic conjugation of pi systems, that is, the aromaticity/antiaromaticity of DBAs. This article reviews these characteristic aspects of strained DBAs. (c) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006.