Quantum Spin–Orbit Electronic State Selection of Atomic Transition Metal Vanadium Cation for Chemical Reactivity Studies
Quantum Spin–Orbit Electronic State Selection of Atomic Transition Metal Vanadium Cation for Chemical Reactivity Studies
复制标题
用于化学反应性研究的原子过渡金属钒阳离子的量子自旋轨道电子态选择
DOI：
10.1021/acs.jpca.9b00511
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Ng, Cheuk-Yiu
中科院分区：
文献类型：
--
作者：
Chang, Yih Chung;Xiong, Bo;Xu, Yuntao;Ng, Cheuk-Yiu
将脉冲激光烧蚀钒原子（V）束源与双色激光序贯电场脉冲（PFI-PI）探测相结合，研制了一种用于离子-分子反应研究的量子自旋轨道选态过渡金属离子源。作为示范，我们表明V+离子可以在其三个最低量子电子态V+[a5 DJ（J= 0-4），a5 FJ（J= 1-5）和a3 FJ（J= 2-4）]的单自旋轨道能级制备，实现实验室动能（Elab）分辨率≤0.2 eV。在紫外-可见光共振增强激光光激发下，先将V原子束通过V*[3d 3（4F）4s 4p（3 P °）]中性中间态激发到高nRydberg态.在54 380 ~ 63 520 cm-1范围内调整光子总能量，以覆盖形成这些自旋轨道态所需的光电离能.在V+[a5 DJ（J= 0和1）]态的PFI-PI谱中发现了收敛到V +[a5 DJ（J= 1和2）]自旋轨道能级的锐Rydberg跃迁。对所观测到的里德堡成员的分析得到V原子的电离能为54412.65 ± 0.15cm-1，与文献值54413 ± 1cm-1 eV非常雅阁。为了理解所观察到的V+离子的PFI-PI谱的轮廓，从而通过使用顺序PFI-PI检测方案获得可靠的斯塔克位移校正，我们还通过改变延迟以及PFI电场脉冲来详细检查Ar+（2 P 3/2）的PFI-PI谱。
By combining a pulsed laser ablation vanadium atom (V) beam source with the two-color laser sequential electric field pulse scheme for pulse field ionization-photoion (PFI-PI) detection, we have developed a quantum spin–orbit state selected transition metal ion source for ion–molecule reaction studies. As a demonstration, we show that the V+ion can be prepared in the single spin–orbit levels of its three lowest quantum electronic states, V+[a5DJ(J= 0–4), a5FJ(J= 1–5), and a3FJ(J= 2–4)], achieving laboratory kinetic energy (Elab) resolutions of ≤0.2 eV. The precursor V atom beam is first excited to high-nRydberg states by resonance-enhanced visible–ultraviolet laser photoexcitation via the V*[3d3(4F) 4s4p (3P°)] neutral intermediate state. The total photon energy is tuned in the regions from 54 380 to 63 520 cm–1to cover the photoionization energies for the formation of these spin–orbit states. Sharp Rydberg transitions converging to the V+[a5DJ(J= 1 and 2)] spin–orbit levels are identified in the respective PFI-PI spectra for the V+[a5DJ(J= 0 and 1)] states. The analysis of these Rydberg members observed yields an ionization energy of 54 412.65 ± 0.15 cm–1for V atom, which is in excellent accord with the literature value of 54 413 ± 1 cm–1eV. In order to understand the profile for the PFI-PI spectrum of V+ion observed and thus obtain reliable Stark shift corrections by using the sequential PFI-PI detection scheme, we have also examined the PFI-PI spectrum for Ar+(2P3/2) in detail by varying the retarding as well as the PFI electric field pulses.