First-Principle Protocol for Calculating Ionization Energies and Redox Potentials of Solvated Molecules and Ions: Theory and Application to Aqueous Phenol and Phenolate
First-Principle Protocol for Calculating Ionization Energies and Redox Potentials of Solvated Molecules and Ions: Theory and Application to Aqueous Phenol and Phenolate
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DOI：
10.1021/jp301925k
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发表时间：
2012-06-21
影响因子：
3.3
通讯作者：
Krylov, Anna I.
中科院分区：
文献类型：
--
作者：
Ghosh, Debashree;Roy, Anirban;Krylov, Anna I.
采用运动方程电离势耦合团簇（EOM-IP-CCSD）和有效碎片势（EFP）方法（简称EOM/EFP）研究了苯酚和苯酚盐在水溶液中的最低垂直电离能（VIE）随水化程度的变化规律，并通过同步辐射和微射流的价电子能谱测量方法进行了实验研究.计算的溶剂诱导的位移VIE（Δ VIE）分别为0.66和+5.72 eV的苯酚和苯酚盐。我们对VIE绝对值的最佳估计（苯酚和酚盐为7.9和7.7 eV）与相应的实验值（7.8 +/- 0.1和7.1 +/- 0.1 eV）相当一致。使用微溶剂化的苯酚和酚盐簇将EOM/EFP方案与完全EOM-IP-CCSD进行基准测试。基于自由能测定的线性响应近似（LRA），开发了一种用EOM/EFP计算氧化还原电位的方法。使用LRA和EOM/EFP计算的苯酚和苯酚盐的氧化电位分别为1.32和0.89 V，与实验值吻合良好。
The effect of hydration on the lowest vertical ionization energy (VIE) of phenol and phenolate solvated in bulk water was characterized using the equation-of-motion ionization potential coupled-cluster (EOM-IP-CCSD) and effective fragment potential (EFP) methods (referred to as EOM/EFP) and determined experimentally by valence photoemission measurements using microjets and synchrotron radiation. The computed solvent-induced shifts in VIEs (Delta VIEs) are 0.66 and +5.72 eV for phenol and phenolate, respectively. Our best estimates of the absolute values of VIEs (7.9 and 7.7 eV for phenol and phenolate) agree reasonably well with the respective experimental values (7.8 +/- 0.1 and 7.1 +/- 0.1 eV). The EOM/EFP scheme was benchmarked against full EOM-IP-CCSD using microsolvated phenol and phenolate clusters. A protocol for calculating redox potentials with EOM/EFP was developed based on linear response approximation (LRA) of free energy determination. The oxidation potentials of phenol and phenolate calculated using LRA and EOM/EFP are 1.32 and 0.89 V, respectively; they agree well with experimental values.