A new diamine monomer containing indole unit, 3,5-diamino-N-(4-(di(1H-indol-3-yl)methyl)phenyl)benzamide, was successfully synthesized and applied in the preparation of a series of polyimides (PIs) via a conventional two-step polymerization procedure with three aromatic tetracarboxylic dianhydrides. The prepared polymers showed excellent solubility in organic solvents such as N-methyl-2-pyrrolidinone (NMP), N,N-dimethylacetamide, and N,N-dimethylformamide. Flexible and strong films of PIs were obtained via casting from their solutions. The glass transition temperature of these polymers was in the range of 223–264°C. They were fairly stable up to a temperature around 300°C and lost 10% weight at 372°C in nitrogen atmosphere. All of the polymers revealed absorption maxima around 323 nm with a fluorescence emission maxima around 378–406 nm in NMP. The cyclic voltammetry of the PIs exhibited an oxidation wave with a peak at 1.07 V. The resulting polymer films had tensile strengths from 83 MPa to 107 MPa, elongates at break of 7–10%, and tensile moduli of 2.2–2.3 GPa.

中文翻译：

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含有 N-(4-(di(1H-indole-3-yl)methyl)phenyl) 部分的高有机可溶性芳香族聚酰亚胺的合成和性能

一种含吲哚单元的新型二胺单体3,5-二氨基-N-(4-(二(1H-吲哚-3-基)甲基)苯基)苯甲酰胺被成功合成并应用于一系列聚酰亚胺的制备( PIs）通过传统的两步聚合程序与三种芳族四羧酸二酐进行聚合。制备的聚合物在 N-甲基-2-吡咯烷酮 (NMP)、N,N-二甲基乙酰胺和 N,N-二甲基甲酰胺等有机溶剂中显示出优异的溶解性。通过从它们的溶液中浇铸获得柔性和坚固的 PI 薄膜。这些聚合物的玻璃化转变温度在 223-264°C 的范围内。它们在高达 300°C 左右的温度下相当稳定，在氮气氛中在 372°C 时重量减少 10%。所有聚合物在 NMP 中显示出约 323 nm 的吸收最大值和约 378-406 nm 的荧光发射最大值。