Wei Gong-Ping, Liu Qing-Yu, Ren Yi, He Sheng-Gui
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. 2021 Oct 1;92(10):104104. doi: 10.1063/5.0059570.
A ship-lock-type reactor has been developed to study ion-molecule reactions of mass-selected ions under high-pressure conditions. Neutral gas molecules can be confined in the reactor by controlling two electromagnet valves to close both the inlet and the outlet of the reactor. Gas-phase ions can be trapped in an ion funnel trap installed in the reactor and interacted with a high-pressure (up to 1000 Pa) reactant gas for a period of time (up to 1 s). The reactions of mass-selected VO with CH and n-CH and mass-selected Au with n-CH were investigated to evaluate the performance of the reactor. The hydrogen atom abstraction product VOH was observed for the reaction of VO with CH, the rate constant was measured to be (1.9 ± 0.4) × 10 cm molecule s, and the kinetic isotope effect value was determined to be 5.4 ± 1.1. Furthermore, the detection limit of n-CH with 1-min measurements was determined to be (19 ± 2) pptv, which is significantly lower than those in previous studies. These results indicate that the current apparatus is a prospective for the study of slow ion-molecule reactions and the detection of trace amounts of gas species, such as volatile organic compounds.
为了研究高压条件下质量选择离子的离子-分子反应，已经开发了一种船闸式反应器。通过控制两个电磁阀关闭反应器的入口和出口，可以将中性气体分子限制在反应器中。气相离子可以被困在安装在反应器中的离子漏斗阱中，并与高压（高达1000 Pa）反应气体相互作用一段时间（长达1 s）。研究了质量选择的VO与CH和正己烷以及质量选择的Au与正己烷的反应，以评估反应器的性能。在VO与CH的反应中观察到了氢原子夺取产物VOH，测得速率常数为(1.9±0.4)×10 cm³分子⁻¹ s⁻¹，动力学同位素效应值确定为5.4±1.1。此外，1分钟测量时正己烷的检测限确定为(19±2) pptv，这明显低于以前研究中的检测限。这些结果表明，当前的装置对于研究慢速离子-分子反应和检测痕量气体物种（如挥发性有机化合物）具有前景。
