Hybrid Lanthanide–Actinide Peroxide Cage Clusters

A cage cluster consisting of 31 uranyl
and 9 Sm3+ polyhedra
self-assembles in an alkaline aqueous peroxide solution and crystallizes
(U31Sm9). Trimers of Sm3+ polyhedra
are templated by μ3-η2:η2:η2-peroxide groups and link to oxo atoms
of uranyl ions. Three such trimers link into a ring through uranyl
hexagonal bipyramids, and these are attached through six polyhedra
to a unit consisting of 21 uranyl hexagonal bipyramids to complete
the cage. Luminescence spectra collected with an excitation wavelength
of 420 nm reveal fine structure, which is not observed for a cluster
containing only uranyl polyhedra.