Crystal and molecular structure of dicaesium µ-(ethylenediaminetetraacetato)-di-µ-sulphido-bis[oxomolybdate(V)] dihydrate

Abstract

The crystal and molecular structure of the title compound was determined by Patterson and Fourier methods from X-ray diffraction data collected by counter methods. Crystals are orthorhombic, space group Pnam, with Z= 4 in a unit cell of dimensions: a= 12·385(3), b= 7·108(3), c= 24·537(3)Å. Full-matrix least-squares refinement of 2196 reflections gave R 0·059. The hexadentate ethylenediaminetetra-acetate (edta) ligand co-ordinates to each molybdenum atom through two carboxylato-oxygens and a nitrogen while two bridging sulphur atoms and a terminal oxygen complete the co-ordination sphere around each molybdenum. The short Mo–Mo bond [2·799(1)Å] suggests that the co-ordination geometry around each metal atom may be described as a distorted capped octahedron sharing a common edge determined by the two sulphur atoms. The molecule possesses a mirror plane, passing through the two sulphur atoms, which necessitates disorder in the ethylenic carbon atoms of the bridging edta ligand.