Physics Department, Sevastopol State University, Universitetskaya St., 33, Crimea, 299053, Sevastopol, Russian Federation.
J Mol Model. 2022 Feb 2;28(2):52. doi: 10.1007/s00894-022-05034-w.
The main goal of this work was to obtain a calculated absorption spectrum of rhodamine 800 in an aqueous solution, which most accurately reproduces the experimental one. To achieve this result, I used the hybrid functionals supported by Gaussian 16 software package. In this case, the basis set (6-31++G(d,p)) and the solvent model (IEFPCM) were not varied. The B3PW91 functional gave the best agreement with the experimental absorption spectrum of the dye in an aqueous medium. B3P86, B971, B972, B98, X3LYP, APF, HSE06, and N12SX functionals also give good absorption energy coincidence. The B3PW91/6-31++G(d,p)/IEFPCM theory level chosen in this way made it possible to calculate the various characteristics of rhodamine 800 in the ground and excited states. An important result of this work was the establishment of the vibronic nature of the short-wavelength smaller maximum of the absorption spectrum. The influence of the strong H-bond of the exocyclic nitrogen atom with the water molecule on the dye excitation was analyzed.
这项工作的主要目标是获得在水溶液中罗丹明 800 的计算吸收光谱，使其最准确地再现实验结果。为了实现这一结果，我使用了 Gaussian 16 软件包支持的混合泛函。在这种情况下，基组（6-31++G(d,p)）和溶剂模型（IEFPCM）没有变化。B3PW91 泛函与染料在水介质中的实验吸收光谱吻合得最好。B3P86、B971、B972、B98、X3LYP、APF、HSE06 和 N12SX 泛函也能很好地符合吸收能。以这种方式选择的 B3PW91/6-31++G(d,p)/IEFPCM 理论水平使得能够计算罗丹明 800 在基态和激发态的各种特性。这项工作的一个重要结果是确定了吸收光谱短波长较小最大值的振子带性质。分析了外环氮原子与水分子之间强氢键对染料激发的影响。
