Laboratorium für Physikalische Chemie, ETH Zürich, 8093 Zürich, Switzerland.
J Chem Phys. 2012 Sep 7;137(9):094308. doi: 10.1063/1.4747549.
Rotationally resolved pulsed-field-ionization zero-kinetic-energy photoelectron spectra of the X 1/2, A(1) 3/2, and A(2) 1/2 electronic states of the ArXe(+) molecular ion have been recorded following resonant (1+1') two-photon excitation via selected rovibrational levels of the C 1 and D 0(+) states of selected isotopomers of the ArXe molecule. Using rovibronic selection and propensity rules for the photoionization out of these intermediate molecular states enabled the determination of the parity of the molecular-ion levels and of the magnitude and sign of the Ω-doubling constants of the coupled X 1/2 (p ≈ 4B) and A(2) 1/2 (p ≈ -2B) states of ArXe(+). The results indicate that these molecular-ion states can be approximately described using Mulliken's second variant of Hund's angular momentum coupling case (c), for which J(a), the total electronic and spin angular momentum of the two atoms, is a good quantum number (semi-united atom). The analysis of the rotational structure enabled the derivation of improved values of the dissociation energies, equilibrium distances, and molecular constants for the X 1/2, A(1) 3/2, and A(2) 1/2 states of ArXe(+).
已记录下经共振（1+1'）双光子激发选定的 ArXe 分子的 C¹ 和 D⁰⁺ 态的选定同位素振动态后，ArXe⁺ 分子离子的 X¹/₂、A(1) 3/₂ 和 A(2) 1/₂ 电子态的旋转分辨脉冲场电离零动能光电电子光谱。利用这些中间分子态的光电离的振转选择和倾向规则，确定了分子离子能级的宇称以及耦合的 X¹/₂（p ≈ 4B）和 A(2) 1/₂（p ≈ -2B）态的 Ω 倍增常数的大小和符号。结果表明，这些分子离子态可以使用 Mulliken 的 Hund 角动量耦合第二变体（c）来近似描述，其中 J(a)，即两个原子的总电子和自旋角动量，是一个好量子数（半统一原子）。旋转结构的分析使我们能够推导出 ArXe⁺ 的 X¹/₂、A(1) 3/₂ 和 A(2) 1/₂ 态的离解能、平衡距离和分子常数的改进值。
