Chemical Trends in Solid Alkali Pertechnetates.
Chemical Trends in Solid Alkali Pertechnetates.
复制标题
固体碱高锝酸盐的化学趋势。
DOI：
10.1021/acs.inorgchem.6b02694
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发表时间：
2017
影响因子：
4.6
通讯作者：
J. McCloy
中科院分区：
文献类型：
--
作者：
Jamie L. Weaver;C. Soderquist;N. Washton;A. Lipton;P. Gassman;W. Lukens;A. Kruger;N. Wall;J. McCloy
在为放射性制药工业、核武器生产和乏核燃料产生的核废料开发强有力的固定和处置系统时，需要深入了解纯锝-99 （99Tc）氧化物的固态化学性质。然而，由于其放射毒性以及随后的研究需要特殊设施和处理程序，只完成了少数研究，其中许多研究已有20多年的历史。在这项研究中，我们报道了纯碱高技术酸盐（钠、钾、铷和铯）的合成，并通过拉曼光谱、x射线吸收光谱（XANES和EXAFS）、固态核磁共振（静态和魔角旋转）和中子衍射对这些化合物进行了分析。这些化合物的结构和光谱特征将有助于进一步了解99Tc与核废料玻璃的结合和释放。NaTcO4表现出Na原子相对较高的电负性，导致高盐四面体的大畸变和99Tc核相对于水溶液TcO4-的去屏蔽。在另一个极端，大的Cs和Rb原子与高技术酸盐的相互作用很弱，Tc原子具有更接近完美的四面体对称性，并且具有非常相似的振动谱，尽管CsTcO4的晶体结构是正交的，而RbTcO4的晶体结构是四方的。在细胞体积和四极耦合常数中观察到进一步的趋势。
Insight into the solid-state chemistry of pure technetium-99 (99Tc) oxides is required in the development of a robust immobilization and disposal system for nuclear waste stemming from the radiopharmaceutical industry, from the production of nuclear weapons, and from spent nuclear fuel. However, because of its radiotoxicity and the subsequent requirement of special facilities and handling procedures for research, only a few studies have been completed, many of which are over 20 years old. In this study, we report the synthesis of pure alkali pertechnetates (sodium, potassium, rubidium, and cesium) and analysis of these compounds by Raman spectroscopy, X-ray absorption spectroscopy (XANES and EXAFS), solid-state nuclear magnetic resonance (static and magic angle spinning), and neutron diffraction. The structures and spectral signatures of these compounds will aid in refining the understanding of 99Tc incorporation into and release from nuclear waste glasses. NaTcO4 shows aspects of the relatively higher electronegativity of the Na atom, resulting in large distortions of the pertechnetate tetrahedron and deshielding of the 99Tc nucleus relative to the aqueous TcO4-. At the other extreme, the large Cs and Rb atoms interact only weakly with the pertechnetate, have closer to perfect tetrahedral symmetry at the Tc atom, and have very similar vibrational spectra, even though the crystal structure of CsTcO4 is orthorhombic while that of RbTcO4 is tetragonal. Further trends are observed in the cell volume and quadrupolar coupling constant.