Wang Lulu, Yin Shiwei
Key Laboratory for Macromolecular Science of Shaanxi Province, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, 710062, Shaanxi, China.
J Mol Model. 2019 Feb 12;25(3):60. doi: 10.1007/s00894-019-3948-0.
The Lippert-Mataga equation is used widely to describe the solvatochromic effects of fluorescent molecules through the evaluation of solute-solvent interactions on the basis of the point-dipole model. A large dipole deviation of molecules in the ground-state and the lowest excited-state is a basic requirement for the design of a polarity-sensitive fluorescent probe. Some recently synthesized probes with center-symmetry have near zero dipole deviation while undergoing notably solvatochromic behaviors. Thus, it is necessary to find a new method beyond the Lippert-Mataga model to qualitatively estimate the molecular solvent shifts. To this end, a state-specific descriptor (SSD) based on molecular surface electrostatic potentials (ESP) is proposed to explain the solvatochromic behaviors of the well-studied coumarin C153 and center-symmetric DCB-1d. In contrast to the experimental solvent shifts and state-specific TD-DFT calculations, the SSD successfully explains the solvatochromic effect of C153 and DCB-1d molecules. In addition, the SSD was tested by using eight selected polarity-sensitive fluorescent molecules. The SSD was found to provide a good linear relationship with solvatochromism.
利珀特-马塔加方程被广泛用于通过基于点偶极子模型评估溶质-溶剂相互作用来描述荧光分子的溶剂化显色效应。分子在基态和最低激发态的大偶极偏差是设计极性敏感荧光探针的基本要求。一些最近合成的具有中心对称性的探针在经历显著的溶剂化显色行为时，其偶极偏差接近零。因此，有必要找到一种超越利珀特-马塔加模型的新方法来定性估计分子的溶剂位移。为此，提出了一种基于分子表面静电势（ESP）的态特异性描述符（SSD），以解释研究充分的香豆素C153和中心对称的DCB-1d的溶剂化显色行为。与实验溶剂位移和态特异性含时密度泛函理论计算相比，SSD成功地解释了C153和DCB-1d分子的溶剂化显色效应。此外，通过使用八个选定的极性敏感荧光分子对SSD进行了测试。结果发现，SSD与溶剂化显色具有良好的线性关系。
