Department of Chemistry, Emory University, Atlanta, Georgia 30322, United States.
J Phys Chem A. 2013 Oct 3;117(39):9684-94. doi: 10.1021/jp312362e. Epub 2013 Feb 19.
Laser induced fluorescence and resonantly enhanced multiphoton ionization spectra were recorded for UF in the 18,000-20,000 cm(-1) range. Rotationally resolved data were obtained, and the analysis of a band at 18624 cm(-1) yielded a ground state rotational constant of 0.2348 cm(-1). The electronic ground state was clearly identified as |Ω| = 4.5, confirming the theoretically predicted U(+)(5f(3)7s(2))F(-) configuration. Dispersed fluorescence spectra revealed low-lying electronic states that are assigned as |Ω| = 3.5 (435 cm(-1)) and 2.5 (650 cm(-1)). Two-color photoionization spectroscopy was used to study UF(+). The ground state and fifteen electronically excited states have been characterized. The ground state was found to be |Ω| = 4, as it is for the isoelectronic molecule UO, and with vibrational constants of ωe = 649.92 and ωexe = 1.83 cm(-1). The patterns of electronically excited states observed for UF(+), with |Ω| values ranging from 0 to 6, were qualitatively consistent with the predictions of a ligand field theory model developed for UO. The experimental data for both UF and UF(+) were reasonably well reproduced by CASSCF/CASPT2 electronic structure calculations that included spin-orbit coupling.
激光诱导荧光和共振增强多光子电离光谱被记录在 UF 在 18000-20000cm(-1) 范围内。获得了旋转分辨数据，并对 18624cm(-1) 处的带进行了分析，得出了基态旋转常数为 0.2348cm(-1)。电子基态被明确地确定为 |Ω| = 4.5，证实了理论上预测的 U(+)(5f(3)7s(2))F(-)构型。荧光光谱揭示了低能电子态，它们被分配为 |Ω| = 3.5(435cm(-1)) 和 2.5(650cm(-1))。双色光电离光谱被用于研究 UF(+)。已经确定了基态和十五个电子激发态。发现基态为 |Ω| = 4，就像等电子分子 UO 一样，其振动常数为 ωe = 649.92 和 ωexe = 1.83cm(-1)。观察到的 UF(+)的电子激发态的模式，|Ω| 值从 0 到 6，与为 UO 开发的配体场理论模型的预测定性一致。UF 和 UF(+)的实验数据都被包括自旋轨道耦合在内的 CASSCF/CASPT2 电子结构计算很好地重现了。
