Mai Sebastian, Ashwood Brennan, Marquetand Philipp, Crespo-Hernández Carlos E, González Leticia
Institute of Theoretical Chemistry, Faculty of Chemistry, University of Vienna , Währinger Strasse 17, 1090 Vienna, Austria.
Center for Chemical Dynamics and Department of Chemistry, Case Western Reserve University , 10900 Euclid Avenue, Cleveland, Ohio 44106, United States.
J Phys Chem B. 2017 May 25;121(20):5187-5196. doi: 10.1021/acs.jpcb.7b02715. Epub 2017 May 12.
The solvatochromic effects of six different solvents on the UV absorption spectrum of 2-thiocytosine have been studied by a combination of experimental and theoretical techniques. The steady-state absorption spectra show significant shifts of the absorption bands, where in more polar solvents the first absorption maximum shifts to higher transition energies and the second maximum to lower energies. The observed solvatochromic shifts have been rationalized using three popular solvatochromic scales and with high-level multireference quantum chemistry calculations including implicit and explicit solvent effects. It has been found that the dipole moments of the excited states account for some general shifts in the excitation energies, whereas the explicit solvent interactions explain the differences in the spectra recorded in the different solvents.
通过实验和理论技术相结合的方法，研究了六种不同溶剂对2-硫代胞嘧啶紫外吸收光谱的溶剂化显色效应。稳态吸收光谱显示吸收带发生了显著位移，在极性更强的溶剂中，第一个吸收最大值向更高的跃迁能量移动，第二个最大值向更低的能量移动。利用三种常用的溶剂化显色标度以及包括隐式和显式溶剂效应的高水平多参考量子化学计算，对观察到的溶剂化显色位移进行了合理解释。研究发现，激发态的偶极矩导致了激发能的一些一般位移，而显式溶剂相互作用则解释了在不同溶剂中记录的光谱差异。
