Seven-co-ordination in chlorohexakis(trimethylphosphine oxide)-uranium(IV) trichloride: crystal and molecular structure

Abstract

The structure to the title compound has been determined by single-crystal X-ray diffraction methods from diffractometer data and refined to a final R of 0.0023. The compound crystallises in space group R3c with a_hex= 18.447(3), c_hex= 19.348(3)Å.Z= 6. The uranium atom is co-ordincate to one chlorine (U–Cl 2.813 Å) and six oxygen atoms (mean U–O 2.26 Å): the co-ordination polyhedron can be described as a distorted monocapped trigonal antiprism or as a distorted monocapped octahedron. The anionic chlorines are more than 6.22 Å from the uranium atoms. The results are discussed in relation to spectral data for this and related uranium(IV) complxes.