Spectroscopic study on hydrogen-bonding and charge resonance interactions in aromatic cluser ions

这个项目的目的是研究以芳香族分子为生色团的团簇中的氢键相互作用。我们建立了脉冲场电离(PFI)-Zeke光电子能谱装置。比较了中性团簇的结构和氢键相互作用，以及氢键作用和电荷共振作用竞争的团簇阳离子的结构和氢键相互作用。我们观察了5-羟基托波酮-CO_2/H_2O和9-羟基苯丙酮-CO_2/H_2O团簇的电子光谱，并结合多维势计算阐明了分子间相互作用对质子隧穿的影响。在4-氨基苯腈-H_2O中已明确鉴定出三个结构异构体。成功地观测到了水中氧原子与氨基质子氢键形成的一种异构体的PFI-Zeke光谱。我们研究了苯胺二聚体阳离子、苯苯胺杂二聚体阳离子和苯-苯甲醇杂二聚体阳离子的稳定结构和分子间相互作用。在苯二聚体离子和苯二聚体离子中，氢键作用占主导地位，没有发生电荷共振作用，而苯-苯甲醇二聚体离子中观察到了电荷共振作用。团簇离子中的分子间相互作用与从头算和密度泛函理论计算得到的稳定结构相关联。结果表明，氢键相互作用对生色团组成原子上的电荷密度非常敏感。

The purpose of this project is to investigate hydrogen bonding interaction in clusters involving an aromatic molecule as a chromophor. We have constructed an apparatus for pulsed field ionization (PFI)-ZEKE photoelectron spectroscopy. The structure and hydrogen bonding interaction in neutral clusters have been compared with those in cluster cations where the hydrogen bonding interaction competes with the charge resonance interaction. We have observed the electronic spectra of 5-hydroxytropolone-CO_2/H_2O and 9-hydroxyphenalenone-CO_2/H_2O clusters, and clarified the effects of intermolecular interaction on proton tunneling combined with multidimensional potential calculations. Three structural isomers have been clearly identified in 4-aminobenzonitrile-H_2O. The PFI-ZEKE spectrum of one isomer, where the oxygen atom of water is hydrogen-bonded to the amino proton, has been successfully observed. We have investigated stable structures and intermolecular interaction in the aniline dimer cation, benzene-aniline hetero-dimer cation, and benzene-benzylalcohol hetero-dimer cation. In the aniline dimer ion and benzene-aniline ion, the hydrogen-bonding interaction is predominant and no charge resonance interaction occurs, whereas the charge resonance interaction has been observed in the benzene-benzylalcohol dimer ion. The intermolecular interaction in the clusters ions has been correlated to the stable structures obtained by ab initio and density functional theory calculations. We have shown that the hydrogen bonding interaction is very sensitive to charge densities on the constitute atoms of the chromophor.