Oxidation of triaryl antimony Ar3Sb [Ar = 4-FC6H4, (4-F3C)C6H4, (2-MeO)C6H4, 4-BrC6H4, 3-MeC6H4, 4-MeC6H4, (4-Me2N)C6H4, (2-MeO)(5-Br)C6H3] with benzoyl peroxide

Oxidation of triarylantimony Ar3Sb with benzoyl peroxide in benzene gave the correspond-ing dibenzoates Ar3Sb[OC(O)Ph]2 [Ar = 4-FC6H4 (1), (4-F3C)C6H4 (2), (2-MeO)C6H4 (3), 4-BrC6H4 (4), 3-MeC6H4 (5), 4-MeC6H4 (6), (4-Me2N)C6H4 (7), (2-MeO)(5-Br)C6H3] (8) with yield up to 93%. Compounds 1–8 were identified by IR spectroscopy and elemental analysis, while compounds 1 and 2 were identified by X-ray analysis. According to X-ray diffraction data, carried out on a Bruker D8 QUEST diffractometer, the crystallographic unit cell parameters of the compounds are: 1, space group P-1, a = 9.1154(3), b = 11.0918(3), c = 14.5437(4) Å, α = 69.9850(10)°, β = 87.5980(10)°, γ = 89.8020(10)°, V = 1380.34(7) Å3, ρcalc = 1.562 g/cm3, Z = 1. F(000) = 648.0, 2θ 5.96–52.88°, crystal dimensions 0.29  0.2  0.2 mm, intervals of re-flection indices 11  h  11, 13  k  13, 18  l  18, total reflections 31527, independent re-flections 11156, refinement variables 721, GOOF 1.069, R1 = 0.0265, wR2 = 0.0549; 2, space group Р-1, а = 10.944(7), b = 12.548(9), c = 13.730(14) Å, α = 83.52(4)°, β = 82.34(5)°, γ = 64.52(3)°, V = 1684(2) Å3, ρcalc = 1.577 g/cm3, Z = 2, F(000) = 792.0, 2θ 4.88–59.22°, crystal dimensions 0.320.280.19 mm, reflection index intervals 14  h  14, 17  k  16, 18  l  18, total reflections 44329, independent reflections 8289, refinement variables 442, GOOF 1.053, R1 = 0.0482, wR2 = 0.1287. Crystals 1 consist of two types of crystallographically independent molecules (A and B), the geometrical parameters of which slightly differ from each other. Antimony atoms in 1 and 2 have a trigonal pyramid coordination with benzoate ligands in axial positions. The Sb–C bond lengths are 2.042(11), 2.081(11), 2.143(9) Å for 1A, 2.091(10), 2.146(11), 2.162(9) Å for 1B, and 2.134(5), 2.135(4), 2.142(4) Å for 2. The Sb–O distances are 2.117(7), 2.128(8) Å for 1A, 2.117(7), 2.128(8) Å for 1B, and 2.127(3), 2.133(3) Å for 2; however, metal atoms are also coordinated by the carbonyl oxygen atoms of bidentate carboxylate ligands [the Sb∙∙∙O=C distances vary in the ranges of 2.669(9)–2.876(9) Å]. The CSbC equatorial angles are not equivalent: the largest angle is observed on the side of intramolecular contacts [103.6(5), 109.0(4), 147.2(4)° for 1A, 105.0(4), 108.1( 4), 146.6(4)° for 1B and 104.39(17), 105.33(17), 150.21(16)° for 2]. The OSbO axial angles are 175.3(4), 176.0(4), and 175.10(10), respectively.