ic6b02429_si_001.pdf (1021.53 kB)
Sulfate-Centered Sodium-Icosahedron-Templated Uranyl Peroxide Phosphate Cages with Uranyl Bridged by μ–η1:η2 Peroxide
journal contribution
posted on 2017-01-30, 14:53 authored by Jie Qiu, Tyler L. Spano, Mateusz Dembowski, Alex M. Kokot, Jennifer E. S. Szymanowski, Peter C. BurnsTwo novel hybrid uranyl peroxide
phosphate cage clusters, designated U20P6 and
U20P12, contain peroxide bridges between uranyl
in an unusual μ–η1:η2 configuration, as well as the common μ–η2:η2 configuration. These appear to be the
only high-nuclearity metal peroxide complexes containing μ–η1:η2 peroxide bridges, and they are unique
among uranyl peroxide cages. Both clusters contain 20 uranyl polyhedra,
and U20P6 and U20P12 contain
6 and 12 phosphate tetrahedra, respectively. The 20 uranyl polyhedra
in both cages are arranged on the vertices of distorted topological
dodecahedrons (20 vertex fullerenes). Each cage is completed by phosphate
tetrahedra and is templated by a sulfate-centered Na12 cluster
with the Na cations defining a regular convex isocahedron. Whereas
μ–η2:η2 peroxides are
essential features of uranyl peroxide cages, where they form equatorial
edges of uranyl hexagonal bipyramids, the μ–η1:η2 peroxide groups in U20P6 and U20P12 are associated with strong
distortions of the uranyl polyhedra. Formation of U20P6 and U20P12 is a further demonstration
of the pliable nature of uranyl polyhedra, which contributes to the
tremendous topological variability of uranyl compounds. Despite the
unusual structure and highly distorted polyhedral geometries of U20P6, small-angle X-ray scattering and Raman spectra
suggest its stability in the aqueous solution and solid state.