Infrared + vacuum ultraviolet two-color ionization spectroscopy of neutral metal complexes based on a tunable vacuum ultraviolet free-electron laser
Gang Li, Chong Wang, Qinming Li, Huijun Zheng, Tiantong Wang, Yong Yu, Mingzhi Su, Dong Yang, Lei Shi, Jiayue Yang, Zhigang He, Hua Xie, Hongjun Fan, Weiqing Zhang, Dongxu Dai, Guorong Wu, Xueming Yang, Ling Jiang
Abstract
This paper describes an experimental technique for studying neutral metal complexes using infrared + vacuum ultraviolet (IR+VUV) two-color ionization spectroscopy based on a tunable VUV free-electron laser (VUV-FEL). The preliminary IR spectroscopy results of mass-selected nickel tetracarbonyl are reported in this work. The results demonstrate that the tunable VUV-FEL light allows the selective ionization of a given neutral cluster free of confinement along with the recording of well-resolved IR spectra. As the ionization energies of many neutral clusters are accessible by a broadly tunable VUV-FEL (50-150 nm) and near-threshold ionization can be readily achieved, the proposed experimental method offers unique possibilities for the size-specific study of a wide variety of confinement-free neutral clusters.