The [U2F12](2-) Anion of Sr[U2F12]

The D-2h-symmetric dinuclear complex anion [U2F12](2-) of pastel green Sr[U2F12] shows a hitherto unknown structural feature: The coordination polyhedra around the U atoms are edge-linked monocapped trigonal prisms, the U-V atoms are therefore seven-coordinated. This leads to a U-U distance of 3.8913(6) angstrom. A weak U-V-U-V interaction is observed for the dinuclear [U2F12](2-) complex and described by the antiferromagnetic exchange J(exp) of circa -29.9 cm(-1). The crystalline compound can be easily prepared from SrF2 and beta-UF5 in anhydrous hydrogen fluoride (aHF) at room temperature. It was studied by means of single crystal X-ray diffraction, IR, Raman and UV/VIS spectroscopy, magnetic measurements, and by molecular as well as by solid-state quantum chemical calculations.