Synthesis and structure of tri(para-tolyl)antimony bis(2-carboxybenzenesulfonate) P-Tol3Sb[OSO2C6H4(COOH)-2]2

Reaction of tri( p -tolyl)antimony with 2-sulfobenzoic acid in ether in the presence of hydrogen peroxide in ether leads to tri( para -tolyl)antimony bis (2-carboxybenzenesulfonate) p -Tol3Sb[OSO2С6H4(COOH)-2]2 (1). According to X-ray diffraction analysis, the antimony atoms in centrosymmetric complex 1 have a distorted trigonal bipyramidal coordination with tolyl substituents in the equatorial plane and arenesulfonate ligands in axial positions, while the CSbО axial angle equals 177.96(12)°. Molecules 1 in the crystal have their own (non-crystallographic) C2 symmetry. The second order axis can be drawn through the Sb(1)C(11)C(14)C(15) atoms. The arenesulfonate substituents are located on one side of the axial axis O(1)Sb(1)O(1’), and their aryl groups form a “stack” with the tolyl substituent C(11)-C(17). In crystal 1 there are contacts of the central atom with the oxygen atoms of the arenesulfonate groups (3.639(9) Å), which are slightly less than the sum of the van der Waals radii of the Sb and S atoms (3.7 Å). In the crystal, molecules 1 are combined into dimers using hydrogen bonds between the carbonyl oxygen atoms and the hydrogen atoms of neighboring carboxyl groups (C=O∙∙∙HOC(O) is 1,85 Å). According to the X-ray diffraction data, the crystallographic characteristics of 1 [C35H31O10S2Sb, M = 797.47; monoclinic system, sp. gr. C 2/c; cell parameters: a = 14.819(9) Å, b = 15.728(11) Å, c = 14.707(9) Å; β = 93.00(2)°, V = 3423(4) Å3, Z = 4; rcalc = 1.547 g/cm3; m = 0.985 mm-1; F(000) = 1616.0; collection region by 2q: 6.84-53.34°; -18 ≤ h ≤ 16, -16 ≤ k ≤ 19, -17 ≤ l ≤ 18; total reflections 6622; independent reflections 3221 ( R int = 0.0433); GOOF = 1.021; R -factor = 0.0381]. Complete tables of atomic coordinates, bond lengths, and bond angles of compound 1 have been deposited in the Cambridge Structural Data Center (CCDC 2336248; deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk). Keywords: tri( para -tolyl)antimony bis (2-carboxybenzenesulfonate), synthesis, structure, X-ray diffraction analysis