Tris(3-trifluoromethylphenyl)antimony. Oxidative addition reactions

Abstract

The reaction of tris(3-trifluoromethylphenyl)antimony with copper(II) chloride in acetone afforded tris(3-trifluoromethylphenyl)antimony dichloride (1) in 91% yield. The oxidation products of tris(3-trifluoromethylphenyl)antimony with bromine or iodine in benzene are dibromide (2) and diiodide (3) obtained in 94% and 81% yields, respectively. Oxidation of tris(3-trifluoromethylphenyl)antimony with benzoyl peroxide in benzene and tert-butyl hydroperoxide in the presence of 3,4-difluorobenzoic acid (molar ratio 1:1:2) in ether is accompanied by the formation of tris(3-trifluoromethylphenyl)antimony dibenzoate (4) and bis(3,4-difluorobenzoate) (5) in 87% and 67% yields. Compounds 1-5 were identified by IR spectroscopy and X-ray diffraction analysis. According to the X-ray analysis data of obtained on an automatic diffractometer D8 Quest Bruker (MoK-radiation, λ = 0.71073 Å, graphite monochromator) at 293 K, of crystals 1 [C21H12F9Cl2Sb, M 627.96; space group P–1, a = 9.029(4), b = 11.036(6), c = 12.530(8) Å, α = 105.52(3) degrees, β = 91.21(3) degrees, γ = 100.432(16) degrees, V = 1179.9(11) Å3, crystal dimensions 0.65×0.33×0.13 mm, reflection index intervals –15 ≤ h ≤ 15, –18 ≤ k ≤ 18, –21 ≤ l ≤ 21, total reflections 78415, independent reflections 12030, Rint 0.0385, GOOF 1.062, R1 = 0.0533, wR2 = 0.1515, residual electron density 1.50/–0.99 e/Å3], 2 [C21H12F9Br2Sb, M 716.88; space group P-1, a = 9.080(11), b = 11.080(11), c = 12.538(12) Å, α = 104.51(3) degrees, β = 91.81(5) degrees, γ = 100.28(6) degrees, V = 1198(2) Å3, crystal dimensions 0.65×0.65×0.47 mm, reflection index intervals –14 ≤ h ≤ 14, –17 ≤ k ≤ 17, –19 ≤ l ≤ 19, total reflections 44442, independent reflections 10014, Rint 0.0908, GOOF 1.052, R1 = 0.0933, wR2 = 0.2223, residual electron density 1.28/–4.96 e/Å3], 3 [C21H12F9I2Sb, M 810.86; space group P21/n, a = 16.933(6), b = 7.588(3), c = 19.587(7) Å, α = 90.00 degrees, β = 98.256(13) degrees, γ = 90.00 degrees, V = 2490.7(17) Å3, crystal dimensions 0.65×0.53×0.3 mm, reflection index intervals –30 ≤ h ≤ 30, –13 ≤ k ≤ 13, –35 ≤ l ≤ 34, total reflections 89517, independent reflections 14969, Rint 0.0580, GOOF 1.075, R1 = 0.0725, wR2 = 0.1448, residual electron density 1.89/–1.86 e/Å3], 4 [C35H22O4F9Sb, M 799.28; space group P–1, a = 10.853(7), b = 11.440(6), c = 15.627(7) Å, α = 106.315(18) degrees, β = 102.12(2) degrees, γ = 103.02(3) degrees, V = 1735(17) Å3, crystal dimensions 0.32×0.24×0.15 mm, reflection index intervals –15 ≤ h ≤ 15, –16 ≤ k ≤ 16, –22 ≤ l ≤ 22, total reflections 117471, independent reflections 10572, Rint 0.0367, GOOF 1.065, R1 = 0.0392, wR2 = 0.1057, residual electron density 1.25/–1.10 e/Å3] and 5 [C70H36O8F26Sb2, M 1742.54; space group P21/c, a = 20.148(5), b = 9.182(2), c = 37.500(11) Å, α = 90.00° degrees, β = 101.116(13) degrees, γ = 90.00 degrees, V = 6807(3) Å3, crystal dimensions 0.46×0.3×0.17 mm, reflection index intervals –24 ≤ h ≤ 25, –11 ≤ k ≤ 11, –48 ≤ l ≤ 48, total reflections 171846, independent reflections 15043, Rint 0.0356, GOOF 1.145, R1 = 0.0447, wR2 = 0.0998, residual electron density 1.46/–1.03 e/Å3] antimony atoms in 1–5 have a trigonal bipyramidal coordination with electronegative ligands in axial positions. The Sb–Hal bond lengths are 2.4576(15), 2.4741(14) Å in 1, 2.605(2), 2.634(2) Å in 2 and 2.8477(10), 2.8709(10) Å in 3. In crystals 4 and 5, the antimony atoms are coordinated by the oxygen atoms of the bidentate carboxylate ligands (the Sb–O and Sb∙∙∙O=C distances are 2.139(2), 2.145(2) and 2.607(7), 2.666(8) Å in 4 and 2.118(2)–2.136(2), 2.607(7)–2.838(9) Å in 5).