SYNTHESIS AND CHARACTERIZATION OF SOLUBLE OLIGO(9,10-ANTHRYLENE)S

A homologous series of oligo(9,10-anthrylene)s up to the heptamer have been synthesized by reductive coupling of quinones with lithioanthrylenes, followed by reductive aromatization of the intermediate hydroxy species. The method used allows the introduction of different alkyl substituents, which ensure sufficient solubility of the newly synthesized anthrylene systems in common organic solvents. The solid-state conformations of trimers 4 and 5 have been established by X-ray structure analysis; UV/Vis-spectroscopic investigations in solution reveal the anthracene moieties in 9,10-anthrylenes to exist as electronically independent electrophores. The trianthrylenes can be subjected to electrophilic substitution which regioselectively provides e.g. 10-bromo- and 10,10''-dibromo derivatives. These bromides can easily be converted into the corresponding cyano compounds. Under the influence of potassium hydroxide in quinoline the trimer 5 partially cyclizes to helianthrene compounds.