A new diimide-diacid, 2,2'-(5-(4-(4-(4,5-diphenyil-1H-imidazol-2-yl) phenoxy)phenylcarbam-oyl)-1,3-phenylenebis(1,3-dioxoisoindoline-5-carboxylic-acid)(DADA), was synthesized from the reaction between trimellitic anhydride and a new diamine, N-(4-(4-(4,5-diphenyl-1H-imidazole-2-yl)phenoxylphenyl)-3,5-diaminobenzamide(NIDA). The direct polycondensation of DADA with various diamines was carried out in NMP in the presence of triphenylposphite and pyridine as condensing agents. The resulting poly(amide-imide)s (PAIs) were amorphous, readily soluble in many polar aprotic solvents and showed inherent viscosities of 0.35-0.47 dL/g. According to thermal analysis, these polymers exhibited glass transition temperatures (T(g)s) in the range of 207-271 degrees C, and their initial decomposition temperature (T(i)) varied from 260 to 330 degrees C and temperature of 10% weight loss (T(10)) from 325 to 520 degrees C in N(2). These polymers in NMP solution exhibited strong UV-vis absorption maxima at 320 nm and their fluorescence emission peaks appeared around 425-450 nm. (C) 2011 Wiley Periodicals, Inc. J Appl Polym Sci 121: 3679-3688, 2011