Department of Chemistry, National Central University, Jhongli, Taiwan 320, Republic of China.
Inorg Chem. 2013 Aug 19;52(16):9172-4. doi: 10.1021/ic401690s. Epub 2013 Aug 1.
An unusaul mixed-valence uranium(V,VI) oxyhydroxide, Na5[U5O16(OH)2], was synthesized via reduction of UO2(2+) with zinc under hydrothermal conditions at 570 °C and 150 MPa. Its structure consists of extended sheets of edge-sharing U(VI) pentagonal bipyramids and U(V) square bipyramids. The overall anion topology is the same as that of the uranyl mineral sayrite, but the squares are populated by U(V)(OH)2(3+) ions. The valence state of uranium was confirmed by X-ray photoelectron spectroscopy. A hydrothermal reaction without zinc under the same reaction conditions yielded a uranyl oxyhydroxide, Na5[U5O17(OH)], with a new sheet structure. The sheet anion topology, which is closely related to that of the mixed-valence compound, contains chains of edge-sharing pentagons as well as dimers of corner-sharing squares.
一种不常见的混合价铀（V，VI）氧氢氧化物，Na5[U5O16(OH)2]，是通过在 570°C 和 150 MPa 的水热条件下用锌还原 UO2(2+)合成的。其结构由 U(VI)五角双锥和 U(V)四方双锥的边缘共享扩展片组成。整体阴离子拓扑与铀矿物硅铍铀矿相同，但正方形由 U(V)(OH)2(3+)离子填充。铀的价态通过 X 射线光电子能谱确认。在相同的反应条件下，没有锌的水热反应生成了具有新片状结构的铀氧氢氧化物，Na5[U5O17(OH)]。片状阴离子拓扑与混合价化合物密切相关，包含边缘共享五边形链以及角共享正方形的二聚体。
