Full-dimensional quantum mechanics calculations for the spectroscopic characterization of the isomerization transition states of HOCO/DOCO systems.
Full-dimensional quantum mechanics calculations for the spectroscopic characterization of the isomerization transition states of HOCO/DOCO systems.
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DOI：
10.1039/c7cp07673h
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发表时间：
2018-02
期刊：
影响因子：
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通讯作者：
Dandan Ma;Haisheng Ren;Jianyi Ma
中科院分区：
文献类型：
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作者：
Dandan Ma;Haisheng Ren;Jianyi Ma
基于精确的势能面，进行了全维量子力学计算以确定HOCO和DOCO的振动能级。从振动基态到3500 cm-1的所有振动能级都被归属，计算的能级与Bowman报道的结果一致.相应的全维波函数呈现出一些特殊的性质。当能级接近势垒高度时，trans-HOCO和cis-HOCO态通过隧穿相互作用强烈耦合，在DOCO体系中观察到隧穿相互作用和费米共振。反式-HOCO、顺式-HOCO和反式-DOCO的能级模式使用Field等人的拟合公式提供了合理的拟合势垒高度，然而，对于被认为是随机事件的顺式-DOCO物质存在差异。我们的全维计算为Field等人报道的异构化过渡态的光谱表征模型的准确性提供了积极的证据，它是从一维模型系统发展而来的。此外，在这项工作中的cis-DOCO的特殊情况意味着同位素取代可以解决的问题，外地的光谱表征模型的意外故障。
Full-dimensional quantum mechanics calculations were performed to determine the vibrational energy levels of HOCO and DOCO based on an accurate potential energy surface. Almost all of the vibrational energy levels up to 3500 cm-1 from the vibrational ground state were assigned, and the calculated energy levels in this work are well in agreement with the reported results by Bowman. The corresponding full dimensional wavefunctions present some special features. When the energy level approaches the barrier height, the trans-HOCO and cis-HOCO states strongly couple through tunneling interactions, and the tunneling interaction and Fermi resonance were observed in the DOCO system. The energy level patterns of trans-HOCO, cis-HOCO and trans-DOCO provide a reasonable fitted barrier height using the fitting formula of Field et al., however, a discrepancy exists for the cis-DOCO species which is considered as a random event. Our full-dimensional calculations give positive evidence for the accuracy of the spectroscopic characterization model of the isomerization transition state reported by Field et al., which was developed from one-dimensional model systems. Furthermore, the special case of cis-DOCO in this work means that the isotopic substitution can solve the problem of the accidental failure of Field's spectroscopic characterization model.