The effect of hydrogen bonding on torsional dynamics: A combined far-infrared jet and matrix isolation study of methanol dimer
The effect of hydrogen bonding on torsional dynamics: A combined far-infrared jet and matrix isolation study of methanol dimer
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DOI：
10.1063/1.4900922
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发表时间：
2014-11-07
影响因子：
4.4
通讯作者：
Larsen, R. Wugt
中科院分区：
文献类型：
--
作者：
Kollipost, F.;Andersen, J.;Larsen, R. Wugt
通过远红外吸收光谱研究了不同的甲醇二聚体同位素体在超音速射流膨胀中分离或在低温下嵌入惰性氖基质中的强分子间氢键对扭转自由度的影响。对于真空隔离和Ne包埋的甲醇二聚体，最终观察到供体亚基的氢键OH解离模式在560 cm（1）附近，相对于游离甲醇单体的OH扭转基频蓝移超过300 cm（1）。在286 cm（1）附近观察到嵌在氖中的受体的OH扭振模。实验结果举行反对谐波预测从本地耦合集群方法与单，双激发和三重激发[LCCSD（T）]和非谐波的微扰治疗。在正则MP2和密度泛函理论（DFT）水平上的VPT2校正，以量化这类重要的分子间氢键振动运动的振动非谐性的贡献。(C)2014 AIP Publishing LLC.
The effect of strong intermolecular hydrogen bonding on torsional degrees of freedom is investigated by far-infrared absorption spectroscopy for different methanol dimer isotopologues isolated in supersonic jet expansions or embedded in inert neon matrices at low temperatures. For the vacuum-isolated and Ne-embedded methanol dimer, the hydrogen bond OH librational mode of the donor subunit is finally observed at similar to 560 cm (1), blue-shifted by more than 300 cm (1) relative to the OH torsional fundamental of the free methanol monomer. The OH torsional mode of the acceptor embedded in neon is observed at similar to 286 cm (1). The experimental findings are held against harmonic predictions from local coupled-cluster methods with single and double excitations and a perturbative treatment of triple excitations [LCCSD(T)] and anharmonic. VPT2 corrections at canonical MP2 and density functional theory (DFT) levels in order to quantify the contribution of vibrational anharmonicity for this important class of intermolecular hydrogen bond vibrational motion. (C) 2014 AIP Publishing LLC.