Optical and electrochemical properties of copoly(aryl ether)s consisting of alternate 2,5-distyrylbenzene and electron-transporting oxadiazole or triazole derivatives

New copoly(aryl ether) P1 consisting of alternate electron-transporting 2-(3-(trifluoromethyl)phenyl)-5-(4-(5-(3-(trifluoromethyl)phenyl)-1,3,4-oxadiazo1-2-yl)-2,5-bis(hexyloxy)phenyl)-1,3,4-oxadiazole and hole-transporting 2,5-distyrylbenzene (DSB) was synthesized via nucleophilic substitution polymerization. We investigated the optical and electrochemical properties of alternate copoly(aryl ether)s P1-P6, which contain the same hole-transporting DSB segments, but with different electron transporting segments. The effect of trifluoromethyl groups in electron transporting segments is also discussed. Referencing to the spectra of their model compounds M1-M4, the emissions of P1-P3 are dominated exclusively by the hole-transporting fluorophores with longer emissive wavelength about 452-453 nm via efficient excitation energy transfer. Furthermore, P1-P3 also exhibit unique variations in energy transfer in acidic media and solvatochromism in organic solvents. The highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) energy levels of P1-P4, estimated from electrochemical data, are -5.12, -5.15, -5.18, -5.00 eV and -2.93, -3.39, -3.49, -2.76 eV, respectively. The electron and hole affinity of P1-P6 can be enhanced simultaneously by introducing isolated hole- and electron-transporting segments in backbone. (c) 2005 Wiley Periodicals, Inc.