Sandoval-Salinas M E, Ricci G, Pérez-Jiménez A J, Casanova D, Olivier Y, Sancho-García J C
Department of Physical Chemistry, University of Alicante, E-03080 Alicante, Spain.
School of Physical and Chemical Science, Queen Mary University of London, London, UK.
Phys Chem Chem Phys. 2023 Oct 11;25(39):26417-26428. doi: 10.1039/d3cp02465b.
In this work, we focus on the understanding of the driving force behind the S-T excited-state energy inversion (which would thus violate Hund's rule, making the S state lower in energy than the T state) of two non-benzenoid non-alternant hydrocarbons, composed of odd-membered rings. The molecules considered here have identical chemical composition but different atomic configuration in space. The delicate interplay between structural and electronic factors that might induce inversion and its energy extension, only by a few meV, is systematically investigated here by state-of-the-art calculations. Qualitative and quantitative accurate predictions are obtained employing post-HF methods, thanks to the balanced and careful inclusion of electron correlation effects. The obtained results might guide and rationalize new searches for molecules violating Hund's rule, concomitantly demonstrating the importance of key contributions from the theoretical method of choice.
在这项工作中，我们专注于理解由奇数元环组成的两种非苯型非交替烃的S-T激发态能量反转背后的驱动力（这将因此违反洪德规则，使S态能量低于T态）。这里考虑的分子具有相同的化学成分，但在空间中具有不同的原子构型。本文通过最先进的计算系统地研究了可能导致反转及其能量扩展（仅几毫电子伏特）的结构和电子因素之间的微妙相互作用。借助后HF方法，通过平衡且仔细地考虑电子相关效应，获得了定性和定量准确的预测。所得结果可能会指导并合理化对违反洪德规则分子的新搜索，同时证明所选理论方法关键贡献的重要性。
