An easy synthetic access to isotruxene and truxene

Le résumé fourni par la source

The two isomers truxene and isotruxene can be considered trimers of indene and are precursors of fullerene synthesis, high strength graphite and derivatives useful in molecular electronics. It is shown that these two isomers are easily accessible by a dehydrotrimerization reaction of indene conducted in a high-pressure crucible through an ordinary DSC (Differential Scanning Calorimeter) scan from ambient temperature to 400 °C–500 °C. It is shown that when the DSC scan is stopped at 400 °C isotruxene and truxene are the main products in a molar ratio of 1.8:1 and are accompanied by indane. When the DSC scan is stopped at 500 °C, isotruxene and truxene are accompanied by the indene tetramers cis- and trans-phenylene-diindeno-fluoranthene derived from isotruxene, so that the molar ratio isotruxene/truxene = 2.5:1. HPLC (High Performance Liquid Chromatography) analysis has shown that isotruxene and truxene are accompanied not only by indane but also by crysene, benzo[a]fluorantene and benzo[b]fluoranthene. The latter three compounds have nothing to do with the indene dehydrotrimerization reaction but are products of direct pyrolysis of indene. Isotruxene and truxene are also produced when polyindene is heated in the high-pressure crucible in a DSC scan to 500 °C. It is suggested that polyindene is thermally decomposed back to indene which in its turn is dehydrotrimerized to isotruxene and truxene. Chemical thermodynamics was used extensively to interpret the results of this study.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.