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| Section2 = }} Fulvalene (bicyclopentadienylidene) is the member of the fulvalene family with the molecular formula C10H8. It is of theoretical interest as one of the simplest non-benzenoid conjugated hydrocarbons. Fulvalene is an unstable isomer of the more common benzenoid aromatic compounds naphthalene and azulene. Fulvalene consists of two 5-membered rings, each with two double bonds, joined by yet a fifth double bond. It has D2h symmetry. An earlier attempt at synthesis of fulvalene in 1951 by Pauson and Kealy resulted in the accidental discovery of ferrocene. Its synthesis was first reported in 1958 by E. A. Matzner at Yale University, working under William von Eggers Doering.〔''Dissertation Abstracts Int'l'' 26-06 page 3270 6411876.〕 In this method, dissertation only and never published, a cyclopentadienyl anion is coupled with iodine to the dihydrofulvalene which is then doubly deprotonated with ''n''-butyllithium to the dianion and then oxidized with oxygen. Fulvalene was spectroscopically observed at 77 K from photolysis of diazocyclopentadiene (dimerization of two cyclopentadiene carbenes) 〔''Photochemical Experiments in Rigid Media at Low Temperatures. II. The Reactions of Methylene, Cyclopentadienylene and Diphenylmethylene'' William B. DeMore, H. O. Pritchard, Norman Davidson J. Am. Chem. Soc., 1959, 81 (22), pp 5874–5879 〕 with UV spectra matching those obtained by the Doering group. Final isolation of the compound came in 1986 〔''Synthese von Pentafulvalen durch oxidative Kupplung von Cyclopentadienid mittels Kupfer(II)-chlorid'' André Escher, Werner Rutsch, Markus Neuenschwander Helvetica Chimica Acta Volume 69 Issue 7, Pages 1644 - 1654 1986 〕 via a method similar to that of Doering. The compound was found to be nonaromatic and extremely reactive above −50 °C through Diels-Alder dimerization. Perchlorofulvalene C10Cl8 is quite stable in contrast to the hydrocarbon.〔Mark, V. “Perchlorofulvalene” Organic Syntheses, Collected Volume 5, p.901 (1973). http://www.orgsyn.org/orgsyn/pdfs/CV5P0901.pdf〕 Tetrathiafulvalene is an organic semiconductor. ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「fulvalene」の詳細全文を読む スポンサード リンク
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