Edelstein Norman M
Chemical Sciences Division, MS 70A-1150, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.
J Phys Chem A. 2015 Nov 12;119(45):11146-53. doi: 10.1021/acs.jpca.5b08576. Epub 2015 Oct 30.
The actinyl ions, consisting of the dioxoactinde(VI) and dioxoactinide(V) ions, are unique in the periodic table. However, very few quantitative studies of the spectra of these ions have been performed. In this paper the analysis of the optical spectrum of the aqueous neptunyl(V) [NpO2(+)] ion in 1 M HClO4 is reexamined. The species in solution is assumed to be the linear NpO2(+) ion surrounded in the equatorial plane by five oxygen atoms from five H2O molecules. The neptunyl(V) ion has the 5f(2) open-shell configuration, and the low-lying optical transitions (up to ∼20 000 cm(-1)) observed are primarily from the two 5f electrons occupying the 5fφ and 5fδ orbitals. The conventional parametric theory used for f(n) systems is applied to these low-lying transitions utilizing the intensity calculations that Matiska et al.1 have performed for this ion and the data reported by Eisenstein and Pryce.2 Possible ratios for the Slater electrostatic repulsion parameters are obtained from the data for the isoelectronic ion U(4+) (5f(2)) in various host crystals. The results are consistent with earlier crystal field analyses of the 5f(1) neptunyl(VI) [NpO2(2+)] ion.
锕酰离子由二氧代锕系元素（VI）和二氧代锕系元素（V）离子组成，在元素周期表中独具特色。然而，对这些离子光谱的定量研究却非常少。本文重新审视了在1 M高氯酸溶液中镎酰（V）[NpO2(+)]离子的光谱分析。溶液中的物种被假定为线性的NpO2(+)离子，其赤道平面被来自五个水分子的五个氧原子包围。镎酰（V）离子具有5f(2)开壳层构型，观察到的低能级光学跃迁（高达约20000 cm(-1)）主要来自占据5fφ和5fδ轨道的两个5f电子。用于f(n)体系的传统参数理论被应用于这些低能级跃迁，利用了马蒂斯卡等人对该离子进行的强度计算以及艾森斯坦和普赖斯报告的数据。从等电子离子U(4+)（5f(2)）在各种基质晶体中的数据获得了斯莱特静电排斥参数的可能比值。结果与早期对5f(1)镎酰（VI）[NpO2(2+)]离子的晶体场分析一致。
