Synthesis and characterization of soluble, photoluminescent polyamides, polyesters and polyethers containing 9,10-di(4-biphenylyl)anthracene segments in the main chain

New rigid polyamides and polyesters as well as semiflexible polyethers containing substituted 9,10-di(4-biphenylyl)athracene segments in the main chain were synthesized through pyrylium salts. They were characterized by viscosimetry, FT-IR, NMR, X-ray, differential scanning calorimetry, the thermomechanical analysis, UV-vis and luminescence spectroscopy. All polymers were practically amorphous and showed an enhanced solubility. Polyamides, that displayed a very high hydrophilicity, dissolved in polar aprotic solvents, strong acids and pyridine. Polyesters and polyethers were soluble in all tested solvents and even in chloroform and THF. Polyamides had higher T(g)s (165-220 degrees C) than polyesters (100-106 degrees C) and polyethers (98-105 degrees C). The polymers with biphenylyl pendent groups showed lower T(g)s and higher thermal stability than their counterparts with phenyl pendent groups. All polymers displayed violet to blue photoluminescence in solution and in solid state with maxima at 366-422 and 435-463 nm, respectively. The polymers carrying biphenylyl pendent groups exhibited in solution more broad emission spectra and higher quantum yields than the corresponding polymers with phenyl pendent groups. (C) 2000 Elsevier Science Ltd. All rights reserved.