Reactions of penta(para-tolyl)antimony with chloroacetic acid

Tetra( para -tolyl)antimony chloroacetate p -Tol4SbOC(O)CH2Cl (1) have been synthesized from equimolar amounts of penta( para -tolyl)antimony and chloroacetic acid in benzene at room temperature. Heating of the initial reagents at the 1:2 molar ratio in refluxing benzene for 1 h leads to formation of bis (chloroacetato)tri( para -tolyl)antimony p -Tol3Sb[OC(O)CH2Cl]2 (2). At room temperature the reaction leads to formation of an adduct of tetra( para -tolyl)antimony chloroacetate with chloroacetic acid p -Tol4SbOC(O)CH2Cl ∙ HOC(O)CH2Cl (3). According to X-ray diffraction analysis performed at 293 K on an automatic four-circle diffractometer D8 Quest Bruker (two-coordinate CCD detector, Mo Kα radiation, λ = 0.71073 Å, graphite monochromator), the antimony atoms in crystals 1 (benzene solvate) [C36H36ClO2Sb, M 657.85; monoclinic system, space group Р 21/ с ; cell parameters: a = 15.540(5), b = 18.925(9), c = 11.639(4) Å; a = 90, β = 109.046(12), g = 90 deg.; V = 3236(2) Å3; crystal size 0.52×0.34×0.24 mm; index ranges -20 ≤ h ≤ 20, -25 ≤ k ≤ 25, -15 ≤ l ≤ 15; total reflections 194800; independent reflections 8200; Rint 0.0383; GOOF 1.035; R 1 = 0.0286, wR 2 = 0.0726; residual electron density 0.68/-0.88 e/Å3], 2 [C25H25O4Cl2Sb, M 582.10; triclinic system, space group P 1 ; cell parameters: a = 10.301(7), b = 11.674(8), c = 12.839(9) Å; a = 106.82(3), β = 104.09(4), g = 108.56(3) deg.; V = 1301.8(15) Å3; crystal size 0.5×0.35×0.25 mm; index ranges -13 ≤ h ≤ 13, -15 ≤ k ≤ 15, -17 ≤ l ≤ 17; total reflections 49027; independent reflections 6552; Rint 0.0337; GOOF 1.156; R 1 = 0.0600, wR 2 = 0.1798; residual electron density 2.16/-2.14 e/Å3], 3 [C32H33O4Cl2Sb, M 674.23; monoclinic system, space group Р 21/ с ; cell parameters: a = 11.74(5), b = 18.95(7), c = 13.98(6) Å; a = 90.00, β = 96.3(2), g = 90.00 deg.; V = 3092(22) Å3; crystal size 0.28×0.16×0.07 mm; index ranges -15 ≤ h ≤ 15, -25 ≤ k ≤ 25, -15 ≤ l ≤ 15; total reflections 76298; independent reflections 6867; Rint 0.1695; GOOF 1.077; R 1 = 0.0623, wR 2 = 0.1311; residual electron density 1.03/-0.70 e/Å3], have a distorted trigonal-bipyramidal coordination with the carbon and oxygen atoms in axial positions (the axial angles are 179.25(7)° and 179.28(7)° for 1, 174.99(15)° for 2, 178.60(17)° for 3). The Sb-O distances are 2.2613(18) Å for 1, 2.151(4) and 2.160(4) Å for 2, and 2.405(9) Å for 3. The Sb-C bond lengths vary within a narrow range of values (2.110(2)-2.128(2) Å for 1, 2.107(5)-2.112(5) Å for 2, 2.060(8)-2.205(9) Å for 3). Structural organization in crystals is due to weak intermolecular contacts of the C=O···H type (2.68-2.68 Å for 1, 2.56-2.63 Å for 2, 2.23-2.71 Å for 3). Crystals 1 and 3 contain Cl···H intermolecular contacts (2.87-2.88 Å and 2.80-2.89 Å). Complete tables of atomic coordinates, bond lengths, and bond angles for the structures are deposited at the Cambridge Crystallographic Data Center (No. 2159564 for 1, No. 2127828 for 2, No. 2142928 for 3; deposit@ccdc.cam.ac.uk; https://www.ccdc.cam.ac.uk).