Crystal and molecular structure of di-µ-sulphido-bis[(L-histidinato)oxomolybdenum(V)] sesquihydrate

Abstract

The crystal and molecular structure of the title compound has been determined from single-crystal three-dimensional X-ray diffraction data collected by counter methods. Crystals are tetragonal, space group P4₁2₁2, with unit-cell dimensions: a=b= 10·549(14), c= 36·510(14)Å, Z= 8. The structure was solved by the heavy-atom method and refined by full-matrix least-squares to R 0·050 (for 3044 observed reflections). Each molybdenum atom is co-ordinated to two bridging sulphur atoms, one terminal oxygen atom, and a terdentate histidinato-ligand. Consideration of the Mo ⋯ Mo distance [2·848(1)Å] suggests the co-ordination geometry around each metal atom can best be described as a seven-co-ordinate distorted capped octahedron sharing a common edge determined by the two sulphur atoms. Factors influencing the co-ordination geometry in this and related complexes are described.