Oxidation of tri-ortho-tolylantimony in the presence of peroxide, oxygen of air and 2,5-dimethylbenzenesulfonic acid. Structure of sulfo-(3-oxo)-tris-(2-oxo)-octa-ortho-tolylantimony

The interaction of tri -ortho -tolylantimony with 2,5-dimethylbenzenesulfonic acid in diethyl ether in air in the presence of tert -butyl hydroperoxide (3:2:3 mol.) synthesized sulfo-(μ 3 -oxo)- tris -(μ 2 -oxo)-octa- ortho -tolylantimony (1), the yield of which after recrystallization from toluene:octane mixtures (5:1 vol.) was 63 %. The X-ray diffraction pattern of crystal 1 was obtained at 293 K on an automatic diffractometer D8 Quest Bruker (Mo Kα -radiation, λ = 0.71073 Å, graphite monochromator), [C42H42O8SSb3, M 1072.07, the monoclinic syngony, the symmetry group P21/c ; cell parameters: a 11.434(5), b 21.609(11), c 18.737(8) Å, α = 90.00 degrees, β = 104.778(14) degrees, γ = 90.00 degrees; V = 4476(4) Å3; the crystal size is 1.05×0.65×0.11 mm; intervals of reflection indexes are -17 ≤ h ≤ 17, -33 ≤ k ≤ 33, -28 ≤ l ≤ 28; total reflections 125015; independent reflections 17125; Rint 0.0579; GOOF 1.044; R 1 = 0.0734, wR 2 = 0.1886; residual electron density 2.75/-1.12 e/Å3] in the trinuclear complex, two atoms of antimony are hexacoordinated (CSbO 159.4(2)-165.4(3)°; OSbO 164.9(2) and 167.4(2)°), the third atom of antimony is in strongly distorted trigonal-bipyramidal coordination (axial angle OSbC 161.9(3)°, equatorial angles OSbC and OSbO vary in the interval 110.5(2)-120.8(4)°). The Sb-С, μ2-O-Sb and μ3-O-Sb bond lengths are 2.095(9)-2.136 (7) Å, 1.904(5)-2.165 (5) Å, and 2.008 (4)-2.387 (5) Å, respectively. The bridge bidentate sulfate ligand is bound to antimony atoms, the Sb-Osulf. distances are 2.100(5) and 2.108(5) Å. Complete tables of coordinates of atoms, bond lengths and valence angles are deposited at the Cambridge Structural Data (No. 1866027; deposit@ccdc.cam.ac.uk; http: //www.ccdc cam.ac.uk.).