Unique crown thioether complexes of f elements: the crystal structure of U(III) and La(III) complexes of 1,4,7-trithiacyclononane.

The crystal structures of the first U(III) complex of a crown thioether and of its La(III) analog have been determined; a stronger M-S interaction is observed for U(III) with respect to La(III) and Ce(III) in solution and in the solid state.