近日，生物分离与界面分子机制研究组（18T7组）在激发态氢键作用机制方面取得进展，通过高精度的理论计算，从分子水平揭示了小分子荧光探针的发光机理，为高效荧光传感机制提供了一种新的策略，有助于光物理和光化学领域中新型荧光探针的设计和开发。

激发态氢键强烈影响分子内电荷转换过程，非常适合高性能荧光探针的设计和开发。然而，二甲基亚砜（DMSO）作为最常用于传感的溶剂或添加剂之一，激发态氢键作用机制中很少被研究。作为这项研究的目标，通过基于密度泛函理论（DFT）的量子化学计算，研究了用于体内一氧化碳释放分子（CORM-3）的CORM3-绿色荧光探针系统的传感机制。在通过降低密度梯度函数和红外光谱分析DMSO的溶剂作用的基础上，我们提供了解释荧光机理的新策略。随后，我们通过邻苯二甲酰亚胺（PTI，CORM3-green的还原产物）的势能曲线验证了该结果。PTI和DMSO之间的激发态氢键促进了辐射跃迁，并导致PTI和PTI-DMSO的光物理性质出现明显差异。

相关成果发表在《中国化学》（Chin. J. Chem. 2020, DOI: 10.1002/cjoc.202000604）上。以上研究工作得到国家自然科学基金、我所创新特区组启动基金、兴辽英才计划等项目的支持。

Sensing Mechanism of Excited-State Intermolecular Hydrogen Bond for Phthalimide: Indispensable Role of Dimethyl Sulfoxide

Dongdong Wang,Tianxin Bai,Xue Wang,Yuting Xiong,Yahui Zhang,Zhenqiang Shi,Fusheng Zhang,Wenqi Lu and Guangyan Qing*

Chin. J. Chem. 2020, 39, 1113-1120

DOI: 10.1002/cjoc.202000604

Excited-state hydrogen bond strongly affects the intramolecular charge conversion process, which is very suitable for the design and development of high-performance fluorescent probes. However, as one of the most common solvents or additives used in sensing, the role of dimethyl sulfoxide (DMSO) in the system of the excited-state hydrogen bond is seldom explored. As the goal of this research, we investigated the sensing mechanism of a CORM3-green fluorescent probe system for carbon monoxide releasing molecule (CORM-3) detection and tracking in vivo, through quantum chemistry calculations based on density-functional-theory (DFT)/ time-dependent density-functional-theory (TDDFT) methods. Based on the analysis of the solvent effect of DMSO by the reduced density gradient function and IR spectroscopy, we provided a new strategy to explain the fluorescence mechanism. Subsequently, we verified the result through the potential energy curve of Phthalimide (PTI, the reduced product of CORM3-green). The excited-state hydrogen bond between PTI and DMSO promotes radiation transition and leads to obvious difference in the photophysical properties of PTI and PTI-DMSO.