A novel coordination geometry for the uranyl ion. Rhombohedral uranium environment in [UO2(OTf)2(bpy)2] and [UO2(phen)3][OTf]2

In the title compounds, the six coordinating ligands atoms of the UO22+ ion are separated into two parallel and staggered equilateral triangles; the UO2 axis is perpendicular to these triangles, passing through their centre, and the U atom is equidistant from the two planes at a distance of ca. 0.6 (angstrom).