The Fulvalenes

Abstract

The fulvalenes are the class of hydrocarbons obtained by formally cross‐conjugating two rings through a common exocyclic double bond. Although the first report of such a compound dates to 1915, study of the series began in earnest only in the 1950s, and even today many of the unsubstituted parent hydrocarbons remain unknown. The following report, the first to specifically address this class of molecules, summarises the information available from research published to the end of 2004 and offers some suggestions for future study. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

Oligomeric and Polymeric Systems with a Cross-conjugated π-Framework

“…Monomeric species based on substructures 1-3, however, are too numerous to address here and have been reviewed previously, including those derived from tetraarylethene, di-, tri-, or tetraethynylene (TEE), 5 fulvalenes, 6 and tetrathiafulvalene. 7,8 Also excluded are systems in which cross conjugation derives solely from a particular substitution pattern about an aromatic ring (e.g., 4-7).…”

Graph Theory of Aromatic Stabilization

“…64, 65 It then is reasonable to presume that 37 and 39 are never highly aromatic. When the ½-technique 66 is applied to them, TREs are markedly reduced to less than one-tenth.…”

Ein Dominoprozess zu Dibenzopentafulvalenen mittels vierfacher Carbopalladierung

“…[2,3] Wurden sie ursprünglich als Kuriositäten mit ungewçhnlichen Bindungslängen und -winkeln wahrgenommen, [4] werden Pentafulvalene mittlerweile als Liganden [5] für Übergangs-metalle sowie als Zwei-Elektronen-Akzeptoren unter Entstehung von aromatischen Dianionen verwendet. [6] Während unsubstituiertes Pentafulvalen instabil bei Temperaturen über À78 8C ist, [7] zeigt das perchlorierte Derivat vollständig reversible Redoxeigenschaften.…”