论文标题
部分Hessian振动分析：蒸气压力同位素效应及其与非共价相互作用的关系
Partial Hessian vibrational analysis: vapour pressure isotope effects and their relation with non-covalent interactions
论文作者
论文摘要
在这项研究中，对纯相估计，估算了纯阶段中估计的纯相（bromobenzene，二溴甲醇，乙醇，甲醇和三氯甲烷）对几种有机溶剂（溴苯，二溴甲醇，乙醇，甲醇和三氯甲烷）蒸发的平衡平衡。 FHVA和PHVA都定性地预测化合物EIE。弱相互作用的系统（Bromobenzene，dibromethane和Trichloromethane）在FHVA和PHVA中都显示出相同的EIE值。而对于强烈相互作用的系统（乙醇和甲醇），PHVA估计与FHVA相比稍小。通过采用对称适应的扰动理论（SAPT）以及独立的梯度模型（IGM），可以确定化合物相互作用能量的最小变化如何影响二溴甲烷中的碳和溴EIES估计。此外，SAPT和IGM揭示了在乙醇中，显然微不足道的分子间相互作用在碳位置特异性同位素效应中具有巨大的影响，这突出了溶剂效应对强相互作用化合物的重要性。提出的结果对于正确理解和表征非共价相互作用在同位素效应的预测中的作用以及为PHVA提供了强大的测试来预测EIE的预测。
In this study equilibrium isotope effects (EIEs) on evaporation to several organic solvents (bromobenzene, dibromomethane, ethanol, methanol, and trichloromethane) in the pure phase are estimated employing Kohn-Sham Density functional theory (KS-DFT) along with full Hessian vibrational analysis (FHVA) and partial Hessian vibrational analysis (PHVA). Both FHVA and PHVA qualitatively predict compounds EIEs. Weakly interacting systems (bromobenzene, dibromomethane, and trichloromethane) display identical EIE values for both, FHVA and PHVA. Whereas for strongly interacting systems (ethanol and methanol), PHVA estimates slightly smaller EIE compared to FHVA. By employing the symmetry-adapted perturbation theory (SAPT) along with independent gradient model (IGM), it was possible to establish how minimal changes in compounds interaction energy affected carbon and bromine EIEs estimation in dibromomethane. Moreover, SAPT and IGM revealed how in ethanol, apparently insignificant intermolecular interactions possessed an enormous impact in carbon position specific isotope effects, which highlight the importance of solvent effects for strongly interacting compounds. The presented results have important implications for correctly comprehending and characterising the role of non-covalent interactions in the prediction of isotope effects, as well as providing a robust test to PHVA for the prediction of EIEs.
