Université de Lille, CNRS, UMR 8516-LASIR-Laboratoire de Spectrochimie Infrarouge et Raman , F-59000 Lille , France.
J Phys Chem B. 2018 Sep 27;122(38):8943-8951. doi: 10.1021/acs.jpcb.8b06062. Epub 2018 Sep 17.
The current study aims at obtaining a better understanding of the mechanisms involved in the complexation of copper ions by 3-hydroxyflavone (3HF), which is one of the most studied compounds of the flavonoid family. To achieve this goal, quantum chemistry calculations combined with electronic spectroscopies, including absorption, fluorescence emission, and excitation, have been used. The formation of successive complexes of stoichiometry (metal/ligand) 1:2, 1:1, and 3:2 has been highlighted. Even under acidic conditions (pH = 4.0), the α-hydroxy-keto function of the molecule presents a high complexing power with regard to copper ions, insofar as a stable complex of 1:2 stoichiometry is obtained with a large conditional stability constant (log β = 8.7). The formation of this predominant species induces a quenching of the dual fluorescence of 3HF, whereas the second complex of stoichiometry 1:1 presents a fluorescence emission.
本研究旨在更好地理解 3-羟基黄酮（3HF）与铜离子络合的机制，3HF 是黄酮类化合物中研究最多的化合物之一。为了实现这一目标，使用了量子化学计算结合电子光谱学，包括吸收、荧光发射和激发。已强调了化学计量比（金属/配体）1:2、1:1 和 3:2 的连续配合物的形成。即使在酸性条件下（pH = 4.0），分子的α-羟基酮官能团对铜离子具有很高的络合能力，因为可以获得具有大条件稳定常数（log β = 8.7）的 1:2 化学计量比的稳定配合物。这种主要物种的形成诱导了 3HF 的双重荧光的猝灭，而化学计量比为 1:1 的第二个配合物则具有荧光发射。
