Synthesis and structure of μ-oxo-bis [(acetylacetonato)(thioacetylacetonato)] dioxodimolybdenum(V) and υ-oxo-[tris(acetylacetonato)(thioacetylacetonato)]dioxodimolybdenum(V)

In the reaction of Mo₂O₃ (acac)₄ and Mo₂O₃ (OAc)₄ with thioacetylacetone two new complexes of molybdenum(V), Mo₂O₃ (acac)₂(Sacac)₂ (complexI) and Mo₂O₃(acac)₃(Sacac) (complexII), respectively, have been prepared. Their crystal structures have been determined from single crystal diffractometer data and refined to the finalR values of 0.068 and 0.044, respectively. Both complexes crystallize in the tetragonal space groupI4₁/a with cell dimensions, (I):a=21.646(3),c=11.627(2) Å,D_calc=1.630 g cm^–3,Z=8 and (II):a=21.240(3),c=11.688(2) Å,D_clac=1.644 g cm^3–,Z=8 and have essentially the same structure. In the structure of (II) half of thioacetylacetone of (I) is statistically replaced by acetylacetone causing thus an occupational disorder in this region of the structure. Both complex molecules are dinuclear and have crystallographically imposed ¯1 symmetry with the bridging oxygen atom in the center of symmetry. Molybdenum atoms exhibit distorted octahedral coordinations. Sulfur atom of the Sacac ligand in (I) shows a considerably largertrans influence than the oxo-oxygen atom.