Vibrational Coupling in Solvated H3O+: Interplay between Fermi Resonance and Combination Band
Vibrational Coupling in Solvated H3O+: Interplay between Fermi Resonance and Combination Band
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溶剂化水中的振动耦合：费米共振与组合能带之间的相互作用
DOI：
10.1021/acs.jpclett.0c03059
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发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Jer-Lai Kuo
中科院分区：
文献类型：
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作者：
Qian-Rui Huang;Ying-Cheng Li;Tomoki Nishigori;Marusu Katada;Asuka Fujii;Jer-Lai Kuo
溶剂化离子H3O+在3μm中的复杂振动特征使我们能够研究O-H伸缩模式与其他自由度之间的振动耦合。有两种非谐耦合方案常被用来解释观察到的光谱：与OH弯曲泛音的耦合，称为费米共振(FR)，用来解释H3O+···Ar3中∼3300 cm-1处的OH伸缩带的分裂，但在相似的频率区域，H3O+···(N2)3中的一个额外峰被指定为与低频率分子间伸展的组合带(CB)。虽然在H3O+···(H2O)3中预期会有更强的振动耦合，但这样的显著峰是不存在的。在本研究中，测量了H3O+···Kr3和H3O+···(CO)3的振动光谱，以补充现有的光谱。利用从头算非调和算法，我们能够赋予观测到的复杂光谱特征，解决解释中看似矛盾的概念，并揭示FR和CB之间相互作用的简单图像。
Complex vibrational features of solvated hydronium ion, H3O+, in 3 μm enable us to look into the vibrational coupling among O–H stretching modes and other degrees of freedom. Two anharmonic coupling schemes have often been engaged to explain observed spectra: coupling with the OH bending overtone, known as Fermi resonance (FR), has been proposed to account for the splitting of the OH stretch band at ∼3300 cm–1in H3O+···Ar3, but an additional peak in H3O+···(N2)3at the similar frequency region has been assigned to a combination band (CB) with the low-frequency intermolecular stretches. While even stronger vibrational coupling is expected in H3O+···(H2O)3, such pronounced peaks are absent. In the present study, vibrational spectra of H3O+···Kr3and H3O+···(CO)3are measured to complement the existing spectra. Usingab initioanharmonic algorithms, we are able to assign the observed complex spectral features, to resolve seemingly contradictory notions in the interpretations, and to reveal simple pictures of the interplay between FR and CB.