A Simple and Efficient Method for Simulating the Electronic Absorption Spectra of Criegee Intermediates: Benchmarking on CH2OO and CH3CHOO
A Simple and Efficient Method for Simulating the Electronic Absorption Spectra of Criegee Intermediates: Benchmarking on CH2OO and CH3CHOO
复制标题
DOI：
10.1021/acs.jpca.1c01074
复制
发表时间：
2021-05-10
影响因子：
2.9
通讯作者：
Karsili, Tolga N., V
中科院分区：
文献类型：
--
作者：
McCoy, Julia C.;Marchetti, Barbara;Karsili, Tolga N., V
Criegee中间体（CI）在大气中起着至关重要的作用，最突出的是增强对流层的氧化能力。了解它们的电子吸收光谱是至关重要的，原因有二：（1）帮助实验人员探测CI;（2）确定CI的去除是否受到太阳光分解的影响。在这篇文章中，我们报告了一个简单而有效的方法的基础上的核系综方法，可以有效地用于计算Criegee中间体的电子吸收光谱，而不需要大量的计算准备的初始几何构型。我们使用这种方法来基准几个激发态的电子结构的方法和它们的效率在再现的电子吸收光谱的两个著名的情况下的CI：CH 2 OO和CH 3CHOO。该方法的成功和计算的可行性是至关重要的，其适用性CI的分子复杂性不断增加，没有已知的实验测量的电子吸收光谱，允许实验指导。将该方法应用于更复杂的CI（例如，具有延长共轭的那些或衍生自内环烯烃的那些）也将揭示当与单分子衰变或双分子化学相比时太阳光分解是否成为竞争性去除过程。
Criegee intermediates (CIs) play a vital role in the atmosphere-known most prominently for enhancing the oxidizing capacity of the troposphere. Knowledge of their electronic absorption spectra is of vital importance for two reasons: (1) to aid experimentalists in detecting CIs and (2) in deciding if their removal is affected by solar photolysis. In this article we report a simple and efficient method based on the nuclear ensemble method that may be effectively used to compute the electronic absorption spectra of Criegee intermediates without the need for extensive computation of preparing the initial configurations of the starting geometry. We use this method to benchmark several excited-state electronic structure methods and their efficacy in reproducing the electronic absorption spectra of two well-known cases of CI: CH2OO and CH3CHOO. The success and computational feasibility of the methodology are crucial for its applicability to CIs of increasing molecular complexity, which have no known experimentally measured electronic absorption spectra, allowing a guide for experimentalists. Application of the methodology to more complex CIs (e.g., those with extended conjugation or those derived from endocyclic alkenes) will also reveal if solar photolysis becomes a competitive removal process when compared to unimolecular decay or bimolecular chemistry.