New fluorinated poly(pyridine amide)s derived from 2,6-bis(4-iodophenyl)-4-(4-trifluoromethylphenyl)pyridine by C–N coupling reaction

2,6-Bis(4-iodophenyl)-4-(4-trifluoromethylphenyl)pyridine, as a new aromatic diiodide compound, was synthesized through a one-pot protocol by the sequential diazotization-iodination of 2,6-bis(4-aminophenyl)-4-(4-trifluoromethylphenyl)pyridine with KI/NaNO2/ p-TsOH in acetonitrile at room temperature. A number of new aromatic fluorinated poly(pyridine amide)s containing 2,6-diphenyl-4-(4-trifluoromethylphenyl)pyridine units were prepared via a Pd(PPh3)2Cl2 catalyzed carbonylation polymerization of this diiodide, diamines and carbon monoxide in DMAc in the presence of PPh3 and 1,8-diazabicyclo[5,4,0]-7-undecene. These new polyamides with inherent viscosities of 0.63–0.72 dL/g were amorphous and easily soluble in amide type aprotic solvents such as NMP, DMAc, DMF and dimethyl sulfoxide at room temperature. Thermal analysis data up to 800°C in nitrogen showed their high thermal behavior with 5% weight loss temperature of 428–498°C and char yield of 62–69%. Their limiting oxygen index of 42.3–45.1 showed that the resulting poly(pyridine amide)s could be classified as “self-extinguishing polymers”. Also, their thin films exhibited high optical transparency with a cut-off wavelength of 324–373 nm.

Synthesis and Excimer Formation Properties of Electroactive Polyamides Incorporated with 4,5-Diphenoxypyrene Units

A new dietherpyrene-cored diamine monomer, namely, 4,5-bis(4-aminophenoxy)pyrene, was successful synthesized and formed a series of electroactive polyamides with an aryloxy linkage in a polymer main chain and bearing pyrene chromophore as a pendent group using conventional one-pot polycondensation reactions with commercial aromatic/aliphatic dicarboxylic acids. The resulting polyamides exhibited good solubility in polar organic solvents and, further, can be made into transparent films. They had appropriate levels of thermal stability with moderately high glass-transition values. The dilute NMP solutions of these polyamides exhibited pyrene characteristic fluorescence and also showed a remarkable additional excimer emission peak centered at 475 nm. Electrochemical studies of these polymer films showed that these polyamides have both p- and n-dopable states as a result of the formation of radical cations and anions of the electroactive pyrene moieties.