Vandaele Eva, Mališ Momir, Luber Sandra
Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057 Zürich, Switzerland.
J Chem Theory Comput. 2024 Apr 23;20(8):3258-3272. doi: 10.1021/acs.jctc.3c01400. Epub 2024 Apr 12.
The photochemistry of nitrophenols is a source of smog as nitrous acid is formed from their photolysis. Nevertheless, computational studies of the photochemistry of these widespread toxic molecules are scarce. In this work, the initial photodeactivation of -nitrophenol and -nitrophenol is modeled, both in gas phase and in aqueous solution to simulate atmospheric and aerosol environments. A large number of excited states, six for -nitrophenol and 11 for -nitrophenol, have been included and were all populated during the decay. Moreover, periodic time-dependent density functional theory (TDDFT) is used for both the explicitly included solvent and the solute. A comparison to periodic QM/MM (TDDFT/MM), with electrostatic embedding, is made, showing notable differences between the decays of solvated nitrophenols simulated with QM/MM and full (TD)DFT. A reduced intersystem crossing in aqueous solution could be observed thanks to the surface hopping approach using explicit, periodic TDDFT solvation including spin-orbit couplings.
硝基酚的光化学是烟雾的一个来源，因为它们的光解会产生亚硝酸。然而，对这些广泛存在的有毒分子的光化学进行的计算研究却很少。在这项工作中，对邻硝基酚和对硝基酚的初始光失活进行了建模，分别在气相和水溶液中进行模拟，以模拟大气和气溶胶环境。计算中纳入了大量激发态，邻硝基酚有6个，对硝基酚有11个，并且在衰变过程中所有这些激发态都被填充。此外，对于显式包含的溶剂和溶质，均使用了周期性含时密度泛函理论（TDDFT）。同时与采用静电嵌入的周期性QM/MM（TDDFT/MM）进行了比较，结果表明用QM/MM和全（TD）DFT模拟的溶剂化硝基酚的衰变之间存在显著差异。借助使用显式、周期性TDDFT溶剂化并包括自旋轨道耦合的表面跳跃方法，可以观察到水溶液中系间窜越的减少。
