Zhou Jian-Ge, Yang Shan, Deng Zhen-Yan, Leszczynski Jerzy
Interdisciplinary Center for Nanotoxicity, Jackson State University, Jackson, Mississippi 39217, United States.
Department of Chemistry, Physics and Atmospheric Science, Jackson State University, Jackson, Mississippi 39217, United States.
J Photochem Photobiol A Chem. 2020 Jun 15;397. doi: 10.1016/j.jphotochem.2020.112504. Epub 2020 Apr 2.
The magnitude of the acidity of the oxyluciferin in water in the ground and excited state is investigated, and it is found for the first time using computational approach that the enol group of the phenol-enol species is the most acidic in the ground state, but the deprotonation of the phenol of the phenol-keto form is the most favored in the excited state. The relative order of the acidity among the hydroxyl groups in the oxyluciferin is attributed to the sequence of the O-H bond lengths in the enol and phenol group of the phenol-enol form, and the phenol group of the phenol-keto species. The mechanism of determining the dominant emissive species in the excited state is proposed, and the dependence of emission light colors on the photoexcitation energy is elucidated by the high relative concentration of six chemical forms in the ground state and the absorption efficiency.
研究了氧化荧光素在基态和激发态水中的酸度大小，首次通过计算方法发现，酚 - 烯醇物种的烯醇基团在基态时酸性最强，但酚 - 酮形式的酚的去质子化在激发态时最有利。氧化荧光素中羟基之间酸度的相对顺序归因于酚 - 烯醇形式的烯醇和酚基团以及酚 - 酮物种的酚基团中O - H键长的顺序。提出了确定激发态中主要发射物种的机制，并通过基态下六种化学形式的高相对浓度和吸收效率阐明了发射光颜色对光激发能量的依赖性。
