Synthesis and characterization of diphenylaminodiphenyl stryl based alternating copolymers

Abstract

Diphenylarninobiphenylated stryl based alternating copolymers with phenyl or fluorene, which were expected to have a terphenylene vinylene backbone containing an (N,N-diphenylamino)biphenyl pendant and a phenyl/fluorene/phenylene vinylene backbone containing an (N,N-diphenylamino)biphenyl pendant, were synthesized by a Suzuki coupling reaction. The obtained copolymers were confirmed with various types of spectroscopy. The alternating copolymers showed good hole-injection properties because of their low oxidation potential and good solubility and high thermal stability with a high glass-transition temperature. The alternating copolymers showed blue emissions because of the adjusted conjugation lengths; the maximum wavelength was 460 nm for poly{4,4'-biphenylene-alpha-[4"-(N,N'-diphenylamino)diphenyl]vinylene-alt-5-(2'-ethylhexyloxy)-2-meth- oxybenzene} and 487 mm for poly{4,4'-biphenylene-alpha-[4"-(N,N'-diphenylamino)diphenyl] vinylene-alt-9,9-dihexylfluorene}. The maximum brightness of indium tin oxide/poly(3,4-ethylene dioxythiophene)/polymer/LiF/Al devices with poly(4,4 -biphenylene-alpha-[4"-(N,N'-diphenylamino)diphenylMnylene-alt-5-(2'-ethylhexyloxy)-2-methoxybenzene} or poly(4,4biphenylene-alpha-[4"-(N,N-diphenylamino)diphenyllvinylene-alt-9,9-dihexylfluorene} as the emitting layer was 250 or 1000 ed/M2, respectively. (c) 2006 Wiley Periodicals, Inc. J Polym Sci.