Ivanov Anatoly I
Volgograd State University, University Avenue 100, Volgograd 400062, Russia.
J Chem Phys. 2023 Aug 7;159(5). doi: 10.1063/5.0161041.
The nature of the second excited state in a quadrupolar molecule of the A-D-A structure, where A and D are an electron acceptor and an electron donor, respectively, has been studied. The orthogonality condition of the wave functions requires that the direction of the molecular dipole moment arising due to the charge transfer symmetry breaking be opposite in the first and second excited states. The dipole moment flip leads to large reorganization energy of the solvent upon excited state absorption. The manifestations of dipole flip are discussed. The dependence of the energy gap on the solvent polarity is found. The symmetry breaking effect on the transition dipole moment suppression is calculated. The available experimental data confirm the main conclusions.
对具有A-D-A结构的四极分子中第二激发态的性质进行了研究，其中A和D分别为电子受体和电子供体。波函数的正交性条件要求，由于电荷转移对称性破缺而产生的分子偶极矩方向在第一激发态和第二激发态中相反。偶极矩翻转导致激发态吸收时溶剂的大重组能。讨论了偶极翻转的表现。发现了能隙对溶剂极性的依赖性。计算了对称性破缺对跃迁偶极矩抑制的影响。现有的实验数据证实了主要结论。
