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 polyphenylenes composed of para-quarterphenylene segments interconnecting at meta-phenylene junctions are presented. The polymers were obtained by nickel catalysed homocoupling of the corresponding 1,5-bis(4-bromophenyl)-2-hydroxy-3,4-dialkoxycarbonylbenzenes. Structural characterisation by microanalysis, FT-IR, 1H and 13C NMR, and UV–Visible spectroscopy agree with the proposed structure of the polymers, with no obvious indication if there are structural defects. Fluorescence analysis of a methylene chloride solution of two materials indicated maximum emission (λmax=463 and 411 nm, respectively) in the visible spectrum.