Related Experiment Video
Updated: Aug 26, 2025
Author Spotlight: Accelerating Discovery in Microporous Material Chemistry
Published on: October 6, 2023
Uranium oxide hydrate frameworks with Er(III) or Y(III) ions: revealing structural insights leading to the low
Timothy A Ablott1, Kimbal T Lu1, Robert D Aughterson1
1Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia. yzx@ansto.gov.au.
Abstract:
Two new mixed-valence uranium oxide hydrate frameworks (UOFs), incorporating either Er3+ or Y3+ ions, were successfully synthesised under hydrothermal conditions and characterised with single-crystal X-ray diffraction and a variety of other structural and spectroscopic techniques. Both frameworks are isostructural and crystallise in the triclinic P1̄ space group, consisting of β-U3O8 type layers pillared by additional uranyl centres, with the Er3+/Y3+ ions lying in the channels of the framework. SEM-EDS analysis found that both materials existed in plate-like morphologies, with a U:Er/Y ratio of 5.5. Bond valence sum analysis revealed the possible existence of pentavalent uranium centres, which was confirmed with diffuse reflectance spectroscopy. Being the first reported UOFs in this space group, this work highlights the complex and flexible nature of these materials, and the broader uranium oxide hydrate systems which exist in the surrounds of spent nuclear fuel disposal in the underground repository.
More Related Videos
12:05U2O5 Film Preparation via UO2 Deposition by Direct Current Sputtering and Successive Oxidation and Reduction with Atomic Oxygen and Atomic Hydrogen
Published on: February 21, 2019
11:27Synthesis and Characterization of Functionalized Metal-organic Frameworks
Published on: September 5, 2014
Related Concept Videos
02:42Ionic Crystal Structures
Most monatomic ions behave as charged spheres, and their attraction for ions of opposite charge is the same in every direction. Consequently, stable structures for ionic compounds result (1) when ions of one charge are surrounded by as many ions as possible of the opposite...
02:34Structural Isomerism
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can...
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
02:54Lewis Structures of Molecular Compounds and Polyatomic Ions
02:42Valence Bond Theory
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...