Borioni José L, Puiatti Marcelo, Vera D Mariano A, Pierini Adriana B
INFIQC - CONICET, Instituto de Investigaciones en Físicoquímica de Córdoba, Departamento de Química Orgánica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, X5000HUA Córdoba, Argentina.
QUIAMM-IMBIOTEC-Departamento de Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata, Mar del Plata, Argentina.
Phys Chem Chem Phys. 2017 Mar 29;19(13):9189-9198. doi: 10.1039/c6cp06163j.
Quantum chemical computational methods are thought to have problems in dealing with unstable organic anions. This work assesses the ability of different Density Functional Theory (DFT) functionals to reproduce the electron affinity and reduction potential of organic compounds. The performance of 23 DFT functionals was evaluated by computing the negative electron affinities (from 0 eV to -3.0 eV) and reduction potentials in acetonitrile (from 0 to -2.7 V). In general, most of the hybrid GGA functionals work fine in the prediction of electron affinities, BPW91, B3PW91 and M06 being the best in each class of functionals (pure, hybrid and meta-GGA functionals, respectively). On the other hand, the ab initio post-Hartree-Fock methods, MP2 and coupled-cluster (CCSD(T)), as well as the double hybrid functionals, B2PLYP and mPW2PLYP, usually fail. For compounds with EAs lower than -1.75 eV, a method for stabilizing the anion, based on solvation with the IEFPCM model, was employed. In this case, BPW91, PBE0 and M06-HF could be the recommended option for the pure, hybrid and meta-GGA functionals, respectively. The situation improves for the evaluation and prediction of redox potentials. In this case the performance of the DFT functionals is better, in part because the solvent assists in the stabilization of the anions. Nevertheless, there is a systematic bias in the calculation of absolute redox potentials, which could be corrected by using a redox partner that helps by the cancellation of errors. In this case, the hybrid and meta-GGA functionals B3PW91, PBE0, TPSSh and M06 are also among the best for computing redox potentials with a mean absolute deviation (MAD) lower than 0.13 V.
量子化学计算方法被认为在处理不稳定有机阴离子方面存在问题。这项工作评估了不同密度泛函理论（DFT）泛函再现有机化合物电子亲和能和还原电位的能力。通过计算乙腈中从0 eV到 -3.0 eV的负电子亲和能以及从0到 -2.7 V的还原电位，评估了23种DFT泛函的性能。总体而言，大多数杂化广义梯度近似（GGA）泛函在电子亲和能预测方面表现良好，BPW91、B3PW91和M06分别在每类泛函（纯泛函、杂化泛函和meta - GGA泛函）中表现最佳。另一方面，从头算后哈特里 - 福克方法、MP2和耦合簇方法（CCSD(T)）以及双杂化泛函B2PLYP和mPW2PLYP通常表现不佳。对于电子亲和能低于 -1.75 eV的化合物，采用了一种基于IEFPCM模型溶剂化来稳定阴离子的方法。在这种情况下，BPW91、PBE0和M06 - HF分别可能是纯泛函、杂化泛函和meta - GGA泛函的推荐选择。对于氧化还原电位的评估和预测情况有所改善。在这种情况下，DFT泛函的性能更好，部分原因是溶剂有助于阴离子的稳定。然而，在绝对氧化还原电位的计算中存在系统偏差，可以通过使用有助于消除误差的氧化还原伙伴来校正。在这种情况下，杂化和meta - GGA泛函B3PW91、PBE0、TPSSh和M06在计算氧化还原电位方面也是最佳的，平均绝对偏差（MAD）低于0.13 V。
