Synthesis and characterization of fluorene-based poly(azomethines)

Novel para or meta-linked fluorene-based poly(azomethines) were synthesized by the reaction of the corresponding dialdehydes and diamines in the presence of anhydrous HMPA, DMSO, and calcium chloride as a dehydrating agent. The resulting polymers were highly soluble in common organic solvents such as THF, chloroform, etc. The molecular weights (M-w) and the polydispersities of the polymers were in the range of 1.0-2.2 x 10(4) and 2.5-2.6, respectively. Their glass transition temperatures were in the range of 137-153 degreesC. We characterized the optical absorption, photoluminescence (PL), and electroluminescence (EL) of the materials. The poly(azomethines) did exhibit PL and EL only after they were protonated with 50 mol% sulfonated polystyrene. The light-emitting devices based on the protonated poly(azomethines) showed white EL. (C) 2002 Elsevier Science B.V. All rights reserved.