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A series of new soluble aromatic polyimides with inherent viscosities of 0.65-1.12 dL/g were synthesized from 1,3-bis(4-aminophenyl)-4,5-diphenylimidazolin-2-one and various aromatic tetracarboxylic dianhydrides by the conventional twostep procedure that included ring-opening polyaddition and subsequent thermal cyclodehydration. These polyimides could also be prepared by the one-pot procedure in homogeneous m-cresol solution. Most of the tetraphenyl-pendant polyimides were soluble in organic solvents such as N,N-dimethylacetamide, 1,3-dimethyl-2-imidazolidone, and m-cresol. Some polyimides gave transparent, flexible, and tough films with good tensile properties. The glass transition temperatures and 10% weight loss temperatures under nitrogen of the polyimides were in the range of 287-326 and 520-580ЊC, respectively.

New diphenylfluorene-based aromatic polyazomethines were synthesized via polycondensation of aromatic diamines with aromatic dialdehydes. The highest inherent viscosity of polyazomethines was obtained for solution polycondensation in m-cresol at room temperature under reduced pressure. The aromatic polyazomethines have inherent viscosities of 0.26-0.36 dL/g. All the polyazomethines are amorphous and most of them are highly soluble in various organic solvents, especially in tetrahydrofuran. Their glass transition temperatures (TJ range from 249 to 335 "C, and the temperatures of 10% weight loss are as high as 490-535 "C in air, indicating that these aromatic polyazomethines have high Tg and excellent theimal stability.