Physics Department, Nakhimov Black Sea Higher Naval School, Dybenko st., 1a, Sevastopol, Crimea 299028.
Physics Department, Sevastopol State University, Universitetskaya st., 33, Sevastopol, Crimea 299053.
Spectrochim Acta A Mol Biomol Spectrosc. 2021 Mar 15;249:119302. doi: 10.1016/j.saa.2020.119302. Epub 2020 Dec 10.
The time-dependent density functional theory (TD-DFT) was used to obtain vibronic absorption spectra of acridine orange dye (AO) in an aqueous solution that were in good agreement with the experiment. The protonated and neutral forms of the dye have been investigated. The results of calculations using various functionals and basis sets have been analyzed. The best agreement with experiment was given by the level of theory X3LYP/6-31G(d,p). AO molecular orbitals involved in electronic transitions due light absorption in the visible region of the spectrum have been obtained. The dipole moments and atomic charges of the ground and excited states of the AO molecule have been calculated. Maps of the electrostatic potential have been drawn. An insignificant photoinduced electron transfer was found in the central ring of the chromophore of the dye molecule. According to our calculations, the vibronic coupling and the Boltzmann distribution play a significant role in the absorption spectra of the AO.
采用含时密度泛函理论（TD-DFT）获得吖啶橙染料（AO）在水溶液中的振子吸收光谱，与实验吻合较好。研究了染料的质子化和中性形式。分析了使用各种泛函和基组的计算结果。与实验吻合最好的是 X3LYP/6-31G(d,p)理论水平。获得了由于吸收光谱可见区域的光而发生电子跃迁的 AO 分子轨道。计算了 AO 分子基态和激发态的偶极矩和原子电荷。绘制了静电势图。在染料分子的生色团中环上发现了光诱导电子转移不明显。根据我们的计算，振子耦合和玻尔兹曼分布在 AO 的吸收光谱中起着重要作用。
