title: Regioselective Synthesis of Nanographenes by Photochemical Cyclodehydrochlorination.
abstract: Novel nanographenes were prepared by a photochemical cyclodehydrochlorination (CDHC) reaction. Chlorinated precursors were irradiated in acetone in the presence of a base or in pure benzene and underwent multiple (up to four) regioselective cyclization reactions to provide rigid π-conjugated molecules. Pure compounds were recovered in good yields by simple filtration at the end of the reaction. The CDHC reaction showed compatibility with both electron-poor and electron-rich substrates, thus allowing the synthesis of pyridine- and thiophene-fused nanographenes. It also enabled the synthesis of sterically hindered contorted π-conjugated molecules without causing full aromatization. A kinetic study showed that the CDHC reaction under the conditions used is a very fast process, and some reactions are completed within minutes. The CDHC reaction thus shows great potential as an alternative to other reactions involving harsher conditions for the preparation of nanographenes.
authors.affiliation: Département de chimie and Centre de Recherche sur les Matériaux Avancés (CERMA), Université Laval, 1045 Ave de la Médecine, Québec, G1V 0A6, Canada.
authors.forename: Maxime
authors.initials: M
authors.lastname: Daigle
authors.affiliation: Département de chimie and Centre de Recherche sur les Matériaux Avancés (CERMA), Université Laval, 1045 Ave de la Médecine, Québec, G1V 0A6, Canada.
authors.forename: Audrey
authors.initials: A
authors.lastname: Picard-Lafond
authors.affiliation: Département de chimie and Centre de Recherche sur les Matériaux Avancés (CERMA), Université Laval, 1045 Ave de la Médecine, Québec, G1V 0A6, Canada.
authors.forename: Eliane
authors.initials: E
authors.lastname: Soligo
authors.affiliation: Département de chimie and Centre de Recherche sur les Matériaux Avancés (CERMA), Université Laval, 1045 Ave de la Médecine, Québec, G1V 0A6, Canada. jean-francois.morin@chm.ulaval.ca.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Morin
keywords: aromatization; carbon materials; nanographenes; photochemistry; polycycles