A detailed account on the photophysics of 3-hydroxyflavone (3HF) in 27 organic solvents is reported. Dual fluorescence of neutral 3HF was observed in protic, polar, and weakly polar solvents, endowed with sufficiently high hydrogen bond accepting and/or donating capabilities. Ground-state solvent-induced 3HF deprotonation was reported in 14 cases. 3HF anion photophysics was investigated, and the deprotonation constant K_dep calculated. Previously reported models (based on solute-solvent intermolecular hydrogen bonds) to explain solvent effects on Excited-State Intramolecular Proton Transfer (ESIPT) and on solvent-induced deprotonation have been re-examined and improved in order to rationalize the observed photophysical behaviour in all the studied solvents. Hydrogen bond donor acidity and hydrogen bond acceptor basicity are shown to be key parameters. The results are discussed in the framework of the use of 3HF as an environment-sensitive fluorescent sensor in several research fields, and as a model system in the study of ESIPT reactions. Solvent effects on 3HF reactivity are also discussed, as the role of the surrounding media on the chemistry of flavonols is an emerging topic in natural product research.

中文翻译：

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溶质-溶剂氢键在3-羟基黄酮中的基态和激发态质子转移中的作用。系统的分光光度法研究。

报告了有关27种有机溶剂中3-羟基黄酮（3HF）的光物理的详细描述。在质子，极性和弱极性溶剂中观察到中性3HF的双重荧光，并具有足够高的氢键接受和/或供电能力。报告了14例基态溶剂诱导的3HF去质子化。研究了3HF阴离子的光物理性质，并得出了去质子常数K _dep计算的。先前报告的模型（基于溶质-溶剂分子间氢键）已被重新审查和改进，以解释所观察到的所有光物理行为，这些模型用于解释溶剂对激发态分子内质子转移（ESIPT）和溶剂诱导的去质子化的影响。研究的溶剂。氢键供体的酸度和氢键受体的碱性被证明是关键参数。在3HF作为对环境敏感的荧光传感器在多个研究领域中的应用以及在ESIPT反应研究中作为模型系统的框架中，对结果进行了讨论。还讨论了溶剂对3HF反应性的影响，因为周围介质对黄酮醇的化学作用是天然产物研究中的一个新兴主题。