Dioxomolybdenum(VI) complexes of quadridentate chiral Schiff bases and the crystal and molecular structure of dioxo[(2R)-propane-1,2-diylbis(salicylideneiminato)]molybdenum(VI)

Dioxomolybdenum(VI) complexes with chiral Schiff bases have been synthesized. The structure of the title compound has been determined by X-ray analysis. The crystals are orthorhombic, space group P212121, with a = 10.382(3), b = 12.127(4), c = 13.298(4) Å, and Z = 4. The structure was determined by the heavy-atom method and refined by least squares to R 0.028 for 2 851 observed reflections. The molecule contains a cis-dioxomolybdenum group and the co-ordinated Schiff-base ligand is bent to form a cis-β structure. The conformations of the compounds in solution are discussed on the basis of 1H and 13C n.m.r. and circular-dichroism spectra.