New intramolecular exciplexes between polynuclear aromatic hydrocarbons and head-to-head vs head-to-tail photodimerization of mesosubstituted anthracenes.

Abstract

New dissymetrical non conjugated bichromophores linked by an oxygenated chain: (9-anthrylmethyloxymethyl)arenes[arenes:benzene(I a),2-naphthalene(I b),9-phenanthrene (I c) and 1-pyrene (I d) and (9-phenanthrylmethyloxymethyl)-1-pyrene (II)] have been prepared. I c–d and II exhibit intramolecular exciplex fluorescence in methylcyclohexane at room temperature. Intramolecular photoadducts were not found but I a–d yield a mixture of head-to-head and head-to-tail anthracenic photodimers.