pH 值对一些黄酮类探针荧光特性的影响。
Effect of pH on the fluorescence characteristics of some flavones probes.
机构信息
Romanian Academy, Institute of Physical Chemistry "Ilie Murgulescu", Splaiul Independentei 202, 060021 Bucharest, Romania.
Department of Physical Chemistry, University of Bucharest, Bd Regina Elisabeta 4-12, 030018 Bucharest, Romania.
出版信息
Spectrochim Acta A Mol Biomol Spectrosc. 2014 Apr 5;123:303-8. doi: 10.1016/j.saa.2013.12.040. Epub 2013 Dec 18.
The photophysical properties such as electronic absorption, molar extinction coefficient, emission spectra, fluorescence quantum yield and lifetime of three different hydroxyflavones (a typical model of flavonols) such as: 3-HF, 3,6-diHF and 3,7-diHF, have been studied in the pH range from 2.5 to 9.2. Both electronic absorption and fluorescence spectra are sensitive to pH. The fluorescence quantum yield at pH 7.4 of the mentioned flavones probes have been determined. The fluorescence lifetime of different emissive species (Normal, Tautomer and Anion forms) as pH dependence have been also estimated. The effect of pH on the intramolecular excited state proton transfer process (ESIPT) has been discussed. The normal and tautomeric forms change as a function of pH, the normal one being more sensitive. The position of the -OH group on the second aromatic ring in the flavonol's structure has been also discussed. The results have relevance to compounds which have photoreactions accompanied by dual fluorescence.
研究了三种不同的羟基黄酮（黄酮醇的典型模型），即 3-HF、3,6-二 HF 和 3,7-二 HF 的光物理性质，如电子吸收、摩尔消光系数、发射光谱、荧光量子产率和寿命。在 pH 值为 2.5 到 9.2 的范围内，电子吸收和荧光光谱都对 pH 值敏感。测定了所提到的黄酮探针在 pH 7.4 时的荧光量子产率。还估计了不同发射物种（正常、互变异构体和阴离子形式）随 pH 值的荧光寿命。讨论了 pH 值对分子内激发态质子转移过程（ESIPT）的影响。正常和互变异构体形式随 pH 值变化，正常形式更敏感。还讨论了黄酮醇结构中第二个芳环上 -OH 基团的位置。这些结果与伴随双荧光的光反应化合物有关。
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