title: 9,10-Disubstituted octafluoroanthracene derivatives via palladium-catalyzed cross-coupling.
abstract: 9,10-Dichlorooctafluoroanthracene (1) reacts with aryl boronic acids and terminal alkynes under palladium-catalyzed cross-coupling conditions to afford 9,10-diaryloctafluoroanthracenes (2a-e) and 9,10-dialkynyloctafluoroanthracenes (6a,b), respectively. Optical spectroscopy and cyclic voltammetry indicate that octafluoro-9,10-di(thiophen-2-yl)anthracene (2d) exhibits donor-acceptor character and a LUMO energy level of -3.27 eV relative to vacuum. A functionalized 5-bromothiophen-2-yl derivative (2e) was obtained in high yield by bromination of 2d with NBS. X-ray crystallographic analysis of octafluoro-9,10-bis[(trimethylsilyl)ethynyl]anthracene (6a) reveals a solid-state structure that mimics the packing of columnar liquid crystals, with a pi stacking distance of 3.39 A between the octafluoroanthracene cores. In addition, octafluoro-9,10-bis(mesitylethynyl)anthracene (6b) displays a LUMO energy level of -3.50 eV, which approaches the value of -3.65 eV measured for perfluoropentacene, making 9,10-dialkynyloctafluoroanthracenes a promising new class of n-type organic materials.
authors.affiliation: Department of Chemistry, University of California at Berkeley, Berkeley, California 94720, USA.
authors.forename: John F
authors.initials: JF
authors.lastname: Tannaci
authors.forename: Masahiro
authors.initials: M
authors.lastname: Noji
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: McBee
authors.forename: T Don
authors.initials: TD
authors.lastname: Tilley