Molecular electronic coupling has been found to play a crucial role in the light-induced processes of natural and artificial systems. The light-induced acoustic process (photoacoustic) is also considered to be one of the most essential characters of the light-absorbing molecules. Herein, we report an interesting observation of the molecular electronic coupling-induced photoacoustic effect (MECPA) in which the PA intensity is dominated by the molecular electronic coupling, rather than the absorption intensity as usually concerned. The molecular electronic coupling effect results in a significant exciton absorption suppression from the monomer to pentamer. However, the corresponding PA efficiency was found to be approximately 2 orders of magnitude greater for the latter. A well-behaved linear correlation between the molecular exciton absorbance and PA efficiency was observed. The surprisingly significant MECPA effect was realized via novel NIR-II squaraine-benzothiopyrylium dyes. Excellent photophysical properties of the novel NIR-II dyes were achieved, such as a large absorption extinction coefficient and high photostability. In vivo duplex PA imaging was demonstrated for tumor tissue and macrophage cells and blood and lymphoid vessels. The MECPA effect would open a new window for the design of PA contrast agent systems for in vivo imaging.

中文翻译：

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用于 NIR-I/II 双工体内成像的分子电子耦合诱导光声学

已发现分子电子耦合在自然和人工系统的光诱导过程中起着至关重要的作用。光诱导声学过程（光声）也被认为是吸光分子最重要的特征之一。在此，我们报告了一个有趣的分子电子耦合诱导光声效应 (MECPA) 观察结果，其中 PA 强度由分子电子耦合决定，而不是通常关注的吸收强度。分子电子耦合效应导致从单体到五聚体的显着激子吸收抑制。然而，发现后者的相应 PA 效率大约高 2 个数量级。观察到分子激子吸光度和 PA 效率之间表现良好的线性相关性。令人惊讶的显着 MECPA 效应是通过新型 NIR-II 方酸-苯并噻吩鎓染料实现的。新型 NIR-II 染料具有优异的光物理特性，例如大的吸收消光系数和高光稳定性。对肿瘤组织和巨噬细胞以及血管和淋巴管进行了体内双重 PA 成像。MECPA 效应将为设计用于体内成像的 PA 造影剂系统打开一个新窗口。如大的吸收消光系数和高光稳定性。对肿瘤组织和巨噬细胞以及血管和淋巴管进行了体内双重 PA 成像。MECPA 效应将为设计用于体内成像的 PA 造影剂系统打开一个新窗口。如大的吸收消光系数和高光稳定性。对肿瘤组织和巨噬细胞以及血管和淋巴管进行了体内双重 PA 成像。MECPA 效应将为设计用于体内成像的 PA 造影剂系统打开一个新窗口。