Seidu Issaka, Goel Prateek, Wang Xiao-Gang, Chen Bo, Wang Xue-Bin, Zeng Tao
Department of Chemistry, Carleton University, Ottawa, Ontario K1S5B6, Canada.
Phys Chem Chem Phys. 2019 Apr 24;21(17):8679-8690. doi: 10.1039/c9cp01352k.
Recently, the negative ion photoelectron spectrum of CO3- was reported and the second lowest energy band is assigned to the close-lying 3E'' and 3E' states that undergo Jahn-Teller distortions (Chem. Sci., 2016, 7, 1142). This assignment is based on the Born-Oppenheimer approximation and the assumption of a static Jahn-Teller effect that distorts the CO3 structure from D3h to C2v symmetry. In this work, we employ a 4 states 6 modes vibronic coupling model to investigate the triplet band and uncover the dynamic and non-adiabatic nature of the Jahn-Teller and pseudo-Jahn-Teller interactions in the triplet states. The apparent four peaks progression in the band is studied in depth, and is found to consist of more than four transitions. By comparing the simulated spectra using the full model and the reduced-dimension 2 states 2 modes models, we characterize those transitions. The origin of the complexities of the spectrum is traced to the C-O nonbonding character of the orbitals that lose electron in the photo-detachment process. Methodology-wise, we derive and present the formalisms for arbitrary order expansions of all bimodal trigonal Jahn-Teller and pseudo-Jahn-Teller Hamiltonians in vibrational coordinates.
最近，有人报道了CO3-的负离子光电子能谱，其第二低能带被指定为经历 Jahn-Teller 畸变的紧邻的3E''和3E'态（《化学科学》，2016年，第7卷，第1142页）。这一指定基于玻恩-奥本海默近似以及静态 Jahn-Teller 效应的假设，该效应使CO3结构从D3h对称性畸变到C2v对称性。在这项工作中，我们采用一个4态6模的振动耦合模型来研究三重态能带，并揭示三重态中 Jahn-Teller 和赝 Jahn-Teller 相互作用的动态和非绝热性质。对能带中明显的四个峰的进展进行了深入研究，发现它由不止四个跃迁组成。通过比较使用完整模型和降维2态2模模型模拟的光谱，我们对这些跃迁进行了表征。光谱复杂性的根源可追溯到在光解离过程中失去电子的轨道的C-O非键合特性。在方法上，我们推导并给出了所有双峰三角 Jahn-Teller 和赝 Jahn-Teller 哈密顿量在振动坐标下任意阶展开的形式。
