Although the uses of uranium in the nuclear industry are well known, the element has a remarkably varied chemistry, exploited, for example, in photooxidation catalysis for the destruction of environmental pollutants. To this end, it is desirable to have compounds in the highest oxidation state of uranium, +VI, 'uranyl' complexes, that are luminescent and insoluble but porous, ideally containing cavities that generate selectivity with regard to absorbed species. Coordination polymers continue to be developed as materials that may provide such properties. (Image credit: Pierre Thuéry.)