Spectroscopic investigations of ThF and ThF+.
Spectroscopic investigations of ThF and ThF+.
复制标题
ThF 和 ThF 的光谱研究。
DOI：
10.1063/1.3691301
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
K. Peterson
中科院分区：
文献类型：
--
作者：
Beau J. Barker;I. Antonov;M. Heaven;K. Peterson
利用激光诱导荧光和共振双光子电离技术研究了ThF和ThF（+）的电子光谱。高级从头计算的结果已用于指导这些数据的分配。ThF的光谱表明分子具有X (2)Δ（3/2）基态。上面的自旋轨道分量X (2)Δ（5/2）的能量为2575(15)cm（-1）。利用分散荧光和脉冲场电离-零动能（PFI-ZEKE）光电子能谱对ThF（+）的低洼态进行了探测。确定了属于四种电子态的振动级数。最低能态明显为(1)Σ（+）和(3)Δ(1)。虽然能量顺序不能严格确定，但证据倾向于(1)Σ（+）作为基态。(3)Δ(1)状态，是研究电子电偶极矩的兴趣点，仅在基态之上315.0(5)cm（-1）处。PFI-ZEKE对ThF的测量结果显示电离能为51 581(3)cm（-1）。分子常数表明，在电离作用下，振动常数增大，键长缩短。这与非成键的以th为中心的6d或7s电子的移除是一致的。激光激发ThF（+）用于探测19,000-21,500 cm（-1）范围内的电子激发态。
The electronic spectra of ThF and ThF(+) have been examined using laser induced fluorescence and resonant two-photon ionization techniques. The results from high-level ab initio calculations have been used to guide the assignment of these data. Spectra for ThF show that the molecule has an X (2)Δ(3/2) ground state. The upper spin-orbit component, X (2)Δ(5/2) was found at an energy of 2575(15) cm(-1). The low-lying states of ThF(+) were probed using dispersed fluorescence and pulsed field ionization-zero kinetic energy (PFI-ZEKE) photoelectron spectroscopy. Vibronic progressions belonging to four electronic states were identified. The lowest energy states were clearly (1)Σ(+) and (3)Δ(1). Although the energy ordering could not be rigorously determined, the evidence favors assignment of (1)Σ(+) as the ground state. The (3)Δ(1) state, of interest for investigation of the electron electric dipole moment, is just 315.0(5) cm(-1) above the ground state. The PFI-ZEKE measurements for ThF yielded an ionization energy of 51 581(3) cm(-1). Molecular constants show that the vibrational constant increases and the bond length shortens on ionization. This is consistent with removal of a non-bonding Th-centered 6d or 7s electron. Laser excitation of ThF(+) was used to probe electronically excited states in the range of 19,000-21,500 cm(-1).