Infrared Spectroscopy of the Ag+−H2 Complex: Exploring the Connection Between Vibrational Band-Shifts and Binding Energies
Infrared Spectroscopy of the Ag+−H2 Complex: Exploring the Connection Between Vibrational Band-Shifts and Binding Energies
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DOI：
10.1021/jz200173m
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发表时间：
2011-03
影响因子：
5.7
通讯作者：
V. Dryza;E. Bieske
中科院分区：
文献类型：
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作者：
V. Dryza;E. Bieske
氢分子在固体介质中的储存通常取决于金属阳离子与H2之间的相互作用。在这些情况下，可以方便地从H2振动的频率评估相互作用的强度。在这里，我们研究了气相Ag+−H2复合物，重点是它的结合能和H2亚基的伸缩频率之间的关系。Ag+−H2的红外光谱是通过探测共振激发产生的Ag+光碎片在H-H伸缩区记录的。部分旋转分辨光谱的分析，考虑到上层状态扰动，确认了T形的平衡几何形状和2.02 A的分子间分离。振动带中心相对于自由H2分子移动了−405.7 ± 1.5 cm−1。一个新的趋势连接的H-H带位移和H2结合能被确定为金属阳离子-H2配合物含有填充或半填充价d轨道。
Storage of molecular hydrogen in solid media often depends on the interaction between metal cations and H2. Under these circumstances, the strength of the interaction can conveniently be assessed from the frequency of the H2 vibration. Here we investigate the gas-phase Ag+−H2 complex, focusing on the relationship between its binding energy and the H2 subunit’s stretch frequency. The infrared spectrum of Ag+−H2 is recorded in the H−H stretch region by detecting Ag+ photofragments resulting from resonant excitation. Analysis of the partially rotationally resolved spectrum, taking upper state perturbations into account, confirms a T-shaped equilibrium geometry and an intermolecular separation of 2.02 A. The vibrational band center is shifted by −405.7 ± 1.5 cm−1 relative to the free H2 molecule. A new trend connecting the H−H band shift and H2 binding energy is identified for metal cation−H2 complexes containing filled or half-filled valence d orbitals.