Solution-processible conjugated electrophosphorescent polymers

Abstract

We report the synthesis and photophysical study of a series of solution-processible phosphorescent iridium complexes. These comprise bis-cyclometalated iridium units [Ir(ppy)2(acac)] or [Ir(btp) 2-(acac)] where ppy is 2-phenylpyridinato, btp is 2-(2′-benzo[b]thienyl)pyridinato, and acac is acetylacetonate. The iridium units are covalently attached to and in conjugation with oligo(9,9- dioctylfluorenyl-2,7-diyl) [(FO)n] to form complexes [Ir(ppy-(FO)n)2(acac)] or [Ir(btp-(FO)n) 2(acac)], where the number of fluorene units, n, is 1, 2, 3, ∼10, ∼20, ∼30, or ∼40. All the complexes exhibit emission from a mixed triplet state in both photoluminescence and electroluminescence, with efficient quench..