How are centrosymmetric and noncentrosymmetric structures achieved in uranyl borates?

Shuao Wang; Evgeny V Alekseev; Jared T Stritzinger; Wulf Depmeier; Thomas E Albrecht-Schmitt

doi:10.1021/ic902480n

How are centrosymmetric and noncentrosymmetric structures achieved in uranyl borates?

Inorg Chem. 2010 Mar 15;49(6):2948-53. doi: 10.1021/ic902480n.

Authors

Shuao Wang¹, Evgeny V Alekseev, Jared T Stritzinger, Wulf Depmeier, Thomas E Albrecht-Schmitt

Affiliation

¹ Department of Civil Engineering and Geological Sciences, 156 Fitzpatrick Hall, University of Notre Dame, Notre Dame, Indiana 46556, USA.

PMID: 20158197
DOI: 10.1021/ic902480n

Abstract

Four uranyl borates, UO(2)B(2)O(4) (UBO-1), alpha-(UO(2))(2)[B(9)O(14)(OH)(4)] (UBO-2), beta-(UO(2))(2)[B(9)O(14)(OH)(4)] (UBO-3), and (UO(2))(2)[B(13)O(20)(OH)(3)].1.25H(2)O (UBO-4), have been prepared from boric acid fluxes at 190 degrees C. UBO-3 and UBO-4 are centrosymmetric, whereas UBO-1 and UBO-2 are noncentrosymmetric (chiral and polar). These uranyl borates possess layered structures constructed from UO(8) hexagonal bipyramids, BO(3) triangles, and BO(4) tetrahedra. In the case of UBO-4, clusters of BO(3) triangles link the layers together to form open slabs with a thickness of almost 2 nm. The ability of uranyl borates to use very similar layers to yield both centrosymmetric and noncentrosymmetric layers is detailed in this work.