Excited-state hydrogen bond strengthening of coumarin 153 in ethanol solvent: a TDDFT study

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• 作者：Jinmei Xu ; Junsheng Chen ; Shunle Dong ; Aiping Fu ; Hongliang Li and Tianshu Chu
• 刊名：Journal of Physical Organic Chemistry
• 出版年：2016
• 出版时间：June 2016
• 年：2016
• 卷：29
• 期：6
• 页码：305-311
• 全文大小：836K
• ISSN：1099-1395

文摘

So far, coumarin dyes have been extensively studied with various means to understand their photophysical behaviors and photochemical properties. Here, our performing time-dependent density functional theory calculation is aimed at exploring the excited-state hydrogen bonding dynamics of coumarin 153 (C153) in protic ethanol (EtOH) solvent. The calculated results suggest that the excited-state hydrogen bond CO⋯HO between CO group and OH group in the C153-EtOH complex is strengthened, and the S₀ → S₁ transition of the complex corresponds to the highest occupied molecular orbital (HOMO) hopping to the lowest unoccupied molecular orbital (LUMO). The excited-state hydrogen bond strengthening has been further confirmed by its larger binding energy in the S₁ state than in the S₀ state. In addition, because of the formation of the hydrogen bond CO⋯HO, a red shift of about 7 nm occurs in the electronic spectra of the C153-EtOH complex, which is in good accordance with the experiment result. Copyright