Zhang Hanyu, Wu Haiming, Jia Yuhan, Geng Lijun, Luo Zhixun, Fu Hongbing, Yao Jiannian
Beijing National Laboratory of Molecular Sciences (BNLMS), State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People's Republic of China.
Rev Sci Instrum. 2019 Jul;90(7):073101. doi: 10.1063/1.5108994.
We have developed an integrated instrument combining deep ultraviolet laser ionization mass spectrometry (DUV-LIMS) and infrared multiphoton dissociation (IR-MPD) spectroscopy, abbreviated as DUV-IR. The 177.3 nm DUV laser (7 eV single-photon energy) has short pulse duration (15 ps) and appropriate pulse energy (∼20 µJ), which is found to be highly efficient for low-fragment photoionization of neutral metal clusters and molecules. A home-made cluster source is designed with an adjustable formation channel suitable for the generation of different cluster series. The well-aligned components of the reflection time-of-flight mass spectrometer, as well as the coaxial design of DUV laser and molecular beam, bring forth high sensitivity and high resolution of the DUV-LIMS. Taking these advantages, well-resolved neutral V (n = 1-43) and (Benzene) (n = 1-25) clusters have been generated free of fragmentation. In addition to the generation and detection of neutral clusters, a fast-flow reaction tube is also designed downstream of the cluster source allowing to study their reactivity. In particular, a broad-range tunable IR laser (1.3-16 µm) is coupled with the DUV laser to attain IR-MPD spectroscopic analysis. This integrated system offers a general protocol to prepare various clusters to study their gas-phase reactivity and to determine their structures.
我们开发了一种将深紫外激光电离质谱（DUV-LIMS）和红外多光子解离（IR-MPD）光谱相结合的集成仪器，简称为DUV-IR。177.3 nm的深紫外激光（单光子能量7 eV）具有短脉冲持续时间（15 ps）和合适的脉冲能量（约20 μJ），已发现其对中性金属团簇和分子的低碎片光电离非常有效。设计了一种自制的团簇源，其形成通道可调，适用于生成不同的团簇系列。反射式飞行时间质谱仪各组件排列良好，以及深紫外激光与分子束的同轴设计，使得DUV-LIMS具有高灵敏度和高分辨率。利用这些优势，已生成了分辨良好的中性V（n = 1 - 43）和（苯）（n = 1 - 25）团簇且无碎片。除了生成和检测中性团簇外，还在团簇源下游设计了一个快速流动反应管，用于研究它们的反应活性。特别是，将一台宽范围可调谐的红外激光（1.3 - 16 µm）与深紫外激光耦合，以实现IR-MPD光谱分析。这个集成系统提供了一个通用方案，用于制备各种团簇以研究它们的气相反应活性并确定其结构。
