The reaction of 4,4’-(1,4-phenylene)bis(2,6-diphenylpyrylium tetrafluoroborate) with nitromethane afforded 4,4(")-dinitro-3,5,3("),5(")-tetraphenyl-p-terphenyl, which was catalytically hydrogenated to the corresponding diamine. The latter was used as starting material for the preparation of new rigid-rod polyamide, polyimides, and polyazomethine bearing phenyl pendent groups as well as the respective model compounds. Characterization of polymers was accomplished by inherent viscosity measurements, elemental analysis, H-1-NMR, C-13-NMR, X-ray, DTA, TMA, TGA, and isothermal gravimetric analysis. The polymers were amorphous and soluble in polar aprotic solvents. Polyamide showed an outstanding solubility, being soluble even in o-dichlorobenzene and chloroform. Polyamide displayed T-g and softening temperature at 135 and 155 degrees C, respectively, whereas other polymers showed only T-g above 265 degrees C. The polymers were stable up to 397-441 degrees C in N-2 and 344-363 degrees C in air and afforded anaerobic char yields of 68-77% at 800 degrees C. In addition, the thermal stability of polyazomethine was investigated as a function of the curing time.