Visible-emitting poly[(3 ',4 '-dialkoxycarbonyl-2 '-hydroxy-1,1 ': 5 ',1 ''-terphenyl-4,4 ''-ylene)]

The synthesis and characterisation of a series of visible-emitting polyphen ylenes composed of para-quarterphenylene segments interconnecting at meta-p henylene junctions are presented. The polymers were obtained by nickel cata lysed homocoupling of the corresponding 1,5-bis(4-bromophenyl)-2-hydroxy-3, 4-dialkoxycarbonylbenzenes. Structural characterisation by microanalysis, F T-IR, H-1 and C-13 NMR, and W-Visible spectroscopy agree with the proposed structure of the polymers, with no obvious indication if there are structur al defects. Fluorescence analysis of a methylene chloride solution of two m aterials indicated maximum emission (lambda(max) = 463 and 411 nm, respecti vely) in the visible spectrum. (C) 1999 Elsevier Science S.A. All rights re served.