Mononuclear to Polynuclear U IV Structural Units: Effects of Reaction Conditions on U‐Furoate Phase Formation
Mononuclear to Polynuclear U IV Structural Units: Effects of Reaction Conditions on U‐Furoate Phase Formation
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单核到多核 U IV 结构单元：反应条件对 U-糠酸盐相形成的影响
DOI：
10.1002/chem.201905759
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发表时间：
2020
期刊：
影响因子：
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通讯作者：
Knope, Karah E.
中科院分区：
文献类型：
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作者：
Vanagas, Nicole A.;Higgins, Robert F.;Wacker, Jennifer N.;Asuigui, Dane Romar;Warzecha, Evan;Kozimor, Stosh A.;Stoll, Sarah L.;Schelter, Eric J.;Bertke, Jeffery A.;Knope, Karah E.
研究了2-糠酸（2-FA）与铀（IV）的络合作用，以更好地了解配体身份和反应条件对物种形成和稳定性的影响。分离出五种化合物：[UCl2（2-FA）2（H2O）2]n（1）、[U4Cl10O2（THF）6（2-FA）2]·2 THF（2）、[U6O4（OH）4（H2O）3（2-FA）12]·7 THF·H2O（3）、[U6O4（OH）4（H2O）2（2-FA）12]·8.76 H2O（4）和[U38Cl42O54（OH）2（H2O）20]·mH2O·nTHF（5）。通过单晶X射线衍射确定结构，并通过拉曼、IR和光学吸收光谱进一步表征。研究了化合物的热稳定性和磁性能。合成条件的变化导致在固态中观察到的结构单元的显着差异。在低的H2O/THF比下，分离出四核氧桥[U4 O2]核。该溶液的老化导致形成由氯和水配体封端的U38氧簇。然而，在增加水的浓度，只有六核单位进行了观察。在所有情况下，在100-120 °C的温度下，UO 2纳米颗粒形成。
Uranium(IV) complexation by 2‐furoic acid (2‐FA) was examined to better understand the effects of ligand identity and reaction conditions on species formation and stability. Five compounds were isolated: [UCl2(2‐FA)2(H2O)2]n(1), [U4Cl10O2(THF)6(2‐FA)2]⋅2 THF (2), [U6O4(OH)4(H2O)3(2‐FA)12]⋅7 THF⋅H2O (3), [U6O4(OH)4(H2O)2(2‐FA)12]⋅8.76 H2O (4), and [U38Cl42O54(OH)2(H2O)20]⋅mH2O⋅nTHF (5). The structures were determined by single‐crystal X‐ray diffraction and further characterized by Raman, IR, and optical absorption spectroscopy. The thermal stability and magnetic behavior of the compounds were also examined. Variations in the synthetic conditions led to notable differences in the structural units observed in the solid state. At low H2O/THF ratios, a tetranuclear oxo‐bridged [U4O2] core was isolated. Aging of this solution resulted in the formation a U38oxo cluster capped by chloro and water ligands. However, at increasing water concentrations only hexanuclear units were observed. In all cases, at temperatures of 100–120 °C, UO2nanoparticles formed.