Soluble, Redox-Active, and Blue-Emitting Poly(amide-hydrazide)s and Poly(amide-1,3,4-oxadiazole)s Containing Pyrenylamine Units

Two new aromatic poly(amide-hydrazide)s (PAHs)-bearing electroactive pyrenylamine units in the backbone were prepared from the phosphorylation polycondensation reactions of N,N-di(4-carboxyphenyl)-1-aminopyrene (1) with p-aminobenzoyl hydrazide (p-ABH) and m-aminobenzoyl hydrazide (m-ABH), respectively. The PAHs could be further cyclodehydrated into the corresponding poly(amide-1,3,4-oxadiazole)s in the range of 300-400 degrees C in the solid film state. All the hydrazide and oxadiazole polymers were soluble in many polar organic solvents and could afford flexible and strong films via solution casting. The poly(amide-1,3,4-oxdiazole)s had high glass-transition temperatures (294-309 degrees C) and high thermal stability (10% weight-loss temperature in excess of 520 degrees C). The dilute solutions of all the hydrazide and oxadiazole polymers showed strong fluorescence with emission maxima around 457-459 nm in the blue region. Copolymers obtained from the polycondensation of equimolar mixture of diacid 1 and 4,4'-oxydibenzoic acid with p-ABH or m-ABH exhibited a significantly increased fluorescence quantum efficiency in comparison with the homopolymers. Cyclic voltammetry results indicated that all the hydrazide and oxadiazole polymers exhibited an ambipolar (nand p-doping processes) and electrochromic behavior. (C) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 49: 4830-4840, 2011