Synthesis and photophysics properties of novel bipolar copolymers containing quinoline aluminum moieties and carbazole segments

A novel polymerizable 8-hydroxyquinoline aluminum (Alq(3)) complex monomer and its copolymers (Alq(3)/N-vinylcarbazole (NVK)) with different mole fractions of Alq(3) in feed were designed and synthesized. The structure of the Alq(3)-complex monomer was characterized by H-1 NMR, FT-IR and elemental analysis, and the bipolar copolymers with various desired Alq(3) loading were characterized by H-1 NMR, FT-IR, elemental analysis, and gel permeation chromatography (GPC). The results indicate that these copolymers have moderate molecular weight as well as good solubility in common organic solvent. Thermal properties measurement and analysis show that these copolymers possess excellent thermal stability and high glass transition temperature (T-g). The photophysics properties of the copolymers were studied by UV-vis and fluorescence spectra. Nearly monochromatic yellow-green emission from Alq(3) was observed in high concentration solution and solid state, showing effective energy transfer characteristic. The results demonstrate that introduction of carbazole as hole-transporting and energy transfer group is a potential method to improve the luminescent performance of the Alq(3)-based polymers. (C) 2011 Elsevier Ltd. All rights reserved.