Near infrared (NIR)‐emissive polymers are attractive luminescent materials due to their utilities in biological, optoelectronic, and telecommunication applications. Herein we report the use of a dialkylamine‐strapped dithienylpyrrole (DTP) as an excited‐state intramolecular proton transfer (ESIPT) building block for producing NIR‐emissive π‐conjugated polymers. The study of a series of model compounds showed that the extension of π‐conjugation with a moderately electron‐accepting comonomer unit, dithientyl‐substituted thiazolo[5,4‐d]thiazole (TzTz), effectively stabilizes the zwitterionic ESIPT state while increasing the oscillator strength for the electronic transition from the ESIPT state. Consequently, a polymer consisted of DTP and TzTz units exhibited a significantly red‐shifted emission, exceeding 750 nm, from the ESIPT state in polar solvents.

中文翻译：

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激发态分子内质子转移单元组成的近红外发射π共轭聚合物

由于近红外（NIR）发射聚合物在生物，光电和电信应用中的实用性，它们是有吸引力的发光材料。在本文中，我们报道了使用二烷基胺键合的二噻吩基吡咯（DTP）作为激发态分子内质子转移（ESIPT）构件来生产NIR发射性π共轭聚合物。对一系列模型化合物的研究表明，具有中等电子接受度的共聚单体单元，二噻吩基取代的噻唑并[5,4-d]噻唑（TzTz）扩展了π共轭，有效地稳定了两性离子的ESIPT状态，同时增加了从ESIPT状态开始电子跃迁的振荡器强度。因此，由DTP和TzTz单元组成的聚合物显示出明显的红移发射，超过750 nm，