Ab Initio Investigation of Intramolecular Charge Transfer States in DMABN by Calculation of Excited State X-ray Absorption Spectra
Ab Initio Investigation of Intramolecular Charge Transfer States in DMABN by Calculation of Excited State X-ray Absorption Spectra
复制标题
通过计算激发态 X 射线吸收光谱从头研究 DMABN 分子内电荷转移态
DOI：
10.1021/acs.jpca.3c01409
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Matthews, Devin A.
中科院分区：
文献类型：
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作者：
Datar, Avdhoot;Gudivada, Saisrinivas;Matthews, Devin A.
对二甲氨基苯甲腈（DMABN）及其衍生物在极性溶剂中的双荧光现象已被广泛研究了几十年。激发态势能表面上的分子内电荷转移（ICT）最小值，除了本地化的低能量（LE）的最小值，已被提出作为这种双重荧光的机制，与大的几何弛豫和分子轨道重组的ICT途径的一个关键特征。在这里，我们已经使用了运动方程耦合团簇与单双激发（EOM-CCSD）和含时密度泛函（TDDFT）的方法来研究景观的激发态势能面在一些几何构象提出的ICT结构。为了关联这些几何形状和价激发态在潜在的实验观测值，我们已经计算了氮K-边缘的地面和激发态吸收光谱的每个预测的“路标”结构，并确定了几个关键的光谱特征，可用于解释未来的时间分辨X射线吸收实验。
Dual fluorescence in 4-(dimethylamino)benzonitrile (DMABN) and its derivatives in polar solvents has been studied extensively for the past several decades. An intramolecular charge transfer (ICT) minimum on the excited state potential energy surface, in addition to the localized low-energy (LE) minimum, has been proposed as a mechanism for this dual fluorescence, with large geometric relaxation and molecular orbital reorganization a key feature of the ICT pathway. Herein, we have used both equation-of-motion coupled-cluster with single and double excitations (EOM-CCSD) and time-dependent density functional (TDDFT) methods to investigate the landscape of excited state potential energy surfaces across a number of geometric conformations proposed as ICT structures. In order to correlate these geometries and valence excited states in terms of potential experimental observables, we have calculated the nitrogen K-edge ground and excited state absorption spectra for each of the predicted “signpost” structures and identified several key spectral features that could be used to interpret a future time-resolved X-ray absorption experiment.