Investigations of Uranyl Fluoride Sesquihydrate (UO2F2•1.57H2O): Combining 19F Solid-State MAS NMR Spectroscopy and GIPAW Chemical Shift Calculations
Investigations of Uranyl Fluoride Sesquihydrate (UO2F2•1.57H2O): Combining 19F Solid-State MAS NMR Spectroscopy and GIPAW Chemical Shift Calculations
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DOI：
10.1021/acs.jpca.8b04369
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发表时间：
2018-08-30
影响因子：
2.9
通讯作者：
Wellons, Matthew S.
中科院分区：
文献类型：
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作者：
DeVore, Michael A., II;Klug, Christopher A.;Wellons, Matthew S.
用F-19魔角旋转（MAS）核磁共振（NMR）谱研究了铀酰氟化物（UO_2F_2）的结构和性质。虽然存在七个不同的晶体学氟位点，但F-19 NMR谱显示在-33.3、9.1、25.7、33.0、39.0和48.2ppm处的六个峰，其中在33.0ppm处的峰是所有其它峰的强度的两倍，因此对应于两个位点。为了将实验光谱中的峰分配给晶体学位点，使用包括投影仪增强波（GIPAW）的平面波赝势方法的规范计算DFT优化的晶体结构的F-19化学位移。DFT的峰归属与二维双量子F-19 MAS NMR实验一致。
High-resolution F-19 magic-angle spinning (MAS) NMR spectra were obtained for the uranium-bearing solid uranyl fluoride sesquihydrate (UO2F2 center dot 1.57H(2)O). While there are seven distinct crystallographic fluorine sites, the F-19 NMR spectrum reveals six peaks at -33.3, 9.1, 25.7, 33.0, 39.0, and 48.2 ppm, with the peak at 33.0 ppm twice the intensity of all the others and therefore corresponding to two sites. To assign the peaks in the experimental spectra to crystallographic sites, F-19 chemical shifts were calculated using the gauge including projector augmented waves (GIPAW) plane-wave pseudopotential approach for a DFT-optimized crystal structure. The peak assignments from DFT are consistent with two-dimensional double-quantum F-19 MAS NMR experiments.