The absorption, scattering, and autofluorescence of biological tissues in short-wave infrared region (SWIR, 900–1700[Formula: see text]nm) are relatively low, so SWIR fluorescence usually has deeper penetration into living tissues, and can show a higher signal-to-noise ratio when used for imaging in vivo. However, there are few types of organic SWIR fluorescent materials currently. In this work, [Formula: see text]-azaquinodimethane ([Formula: see text]-AQM) with a quinoid structure is used as the acceptor unit, and carbazole or fluorene with sp3 hybridization are used as the donor units, two conjugated polymers were synthesized. The quinone structure is conducive to the redshift of absorption and fluorescence spectra, and the sp3 hybridization structure is conducive to weakening the aggregation quenching of polymer fluorescence. PF and PCz exhibited absorption peaks of 492[Formula: see text]nm and 508[Formula: see text]nm, respectively. The emission peaks of the two polymers are 920[Formula: see text]nm and 950[Formula: see text]nm, respectively, both in the short-wave near infrared region. The quantum yield (QY) of PF and PCz is 0.4% and 0.3%, respectively.

中文翻译：

---

两种对氮杂醌二甲烷（p-AQM）基共轭聚合物的短波近红外荧光特性

生物组织在短波红外区（SWIR，900-1700[公式：见正文]nm）的吸收、散射和自发荧光相对较低，因此SWIR荧光通常对活组织具有更深的穿透力，可以表现出更高的用于体内成像时的信噪比。然而，目前有机短波红外荧光材料种类较少。本工作以具有醌式结构的[分子式：见正文]-氮杂醌二甲烷（[分子式：见正文]-AQM）为受体单元，以具有sp3杂化的咔唑或芴为供体单元，两种共轭聚合物被合成了。醌结构有利于吸收和荧光光谱的红移，sp3杂化结构有利于减弱聚合物荧光的聚集猝灭。PF 和 PCz 的吸收峰分别为 492[公式：见正文]nm 和 508[公式：见正文]nm。两种聚合物的发射峰分别为 920[公式：见正文]nm 和 950[公式：见正文]nm，均在短波近红外区域。PF 和 PCz 的量子产率 (QY) 分别为 0.4% 和 0.3%。