
%0 Journal Article
%A Banciu, MD 
%A Brown, RFC 
%A Coulston, KJ 
%A Eastwood, FW 
%A Jurss, C 
%A Mavropoulos, I 
%A Stanescu, M 
%A Wiersum, UE 
%T Formation of Cyclopent[<I>hi</I>]acephenanthrylene From 1,2-, 1,3-, 1,4- and 2,3-Triphenylenedicarboxylic Acid Derivatives on Flash Vacuum Pyrolysis at >900&#176;C
%J Australian Journal of Chemistry
%D 1996/09/01
%V 49
%N 9
%P 965-976
%K 
%R https://doi.org/10.1071/CH9960965
%U https://www.publish.csiro.au/paper/CH9960965 
%X The processes involved in the conversion of triphenylene , C18H12, into cyclopent [hi] acephenanthrylene, C18H10, under flash vacuum pyrolytic conditions at 900-1100&#176;C have been investigated by pyrolysing triphenylene-1,2- and -2,3-dicarboxylic anhydrides and diallyl triphenylene-1,3- and -1,4-dicarboxylates to give the corresponding didehydrotriphenylenes in the gas phase. These didehydro intermediates are converted into mixtures of cyclopent [hi] acephenanthrylene and triphenylene in different yields and proportions. Pyrolysis of 9,10-diethynylphenanthrene. C18H10, yields cyclopent [hi] acephenanthrylene in good yield. Pyrolysis of 1-nitrotriphenylene and allyl triphenylene-2-carboxylate to give the triphenylen-1-yl and -2-yl radicals leads to formation of the same products. Mechanisms involving radical rearrangements (C18H11 species) and benzyne-cyclopentadienylidenecarbene and ethyne-ethenylidene rearrangements (C18H10 species) are discussed. 
