Discovery of Cs2(UO2)Al2O5 by Molten Flux Methods: A Uranium Aluminate Containing Solely Aluminate Tetrahedra as the Secondary Building Unit

Christian A Juillerat; Vancho Kocevski; Theodore M Besmann; Hans-Conrad Zur Loye

doi:10.1021/acs.inorgchem.9b00435

Discovery of Cs₂(UO₂)Al₂O₅ by Molten Flux Methods: A Uranium Aluminate Containing Solely Aluminate Tetrahedra as the Secondary Building Unit

Inorg Chem. 2019 Apr 1;58(7):4099-4102. doi: 10.1021/acs.inorgchem.9b00435. Epub 2019 Mar 12.

Authors

Christian A Juillerat^{1

2}, Vancho Kocevski^{3

2}, Theodore M Besmann^{3

2}, Hans-Conrad Zur Loye^{1

2}

Affiliations

¹ Department of Chemistry and Biochemistry , University of South Carolina , Columbia , South Carolina 29208 , United States.
² Center for Hierarchical Wasteform Materials (CHWM) , University of South Carolina , Columbia , South Carolina 29208 , United States.
³ Nuclear Engineering Program , University of South Carolina , Columbia , South Carolina 29208 , United States.

PMID: 30860816
DOI: 10.1021/acs.inorgchem.9b00435

Abstract

The flux synthesis, solid state synthesis, and characterization of a new aluminate, Cs₂(UO₂)Al₂O₅, are reported. Cs₂(UO₂)Al₂O₅ crystallizes in the tetragonal space group I4₁/ amd with lattice parameters a = 7.3254(2) and c = 30.9849(7) and is constructed from edge-sharing chains of UO₇ pentagonal bipyramids that are connected to [Al₂O₅]^4- two-dimensional sheets. The cesium cations, which are heavily disordered, occupy small channels in the a and b directions in the framework structure. The optical properties and ion exchange behaviors are reported along with DFT calculations that support the observed results of the ion exchange experiments.