Synthesis and crystal structure of tris(3-fluorophenyl)antimony bis(2-methylcarboranylcarboxylate)

Oxidation of tris (3-fluorophenyl)antimony with hydrogen hydroperoxide in the presence of 2-methylcarboranylcarboxylic acid leads to the formation of tris (3-fluorophenyl)antimony bis (2-methylcarboranylcarboxylate) (1), the structural features of which have been established by X-ray diffraction analysis. According to X-ray diffraction analysis performed at 293 K on an automatic four-circle diffractometer D8 Quest Bruker (two-coordinate CCD detector, Mo K α -radiation, λ = 0.71073 Å, graphite monochromator), the crystals are characterized by: C26H38B20F3O4Sb, M 809.52; monoclinic system, space group C 2/ c ; cell parameters: a = 19.050(13), b = 14.441(9), c = 14.568(9) Å; a = 90°, β = 98.51(2)°, g = 90°; V = 3964(4) Å3; Z = 4; crystal size 0.8 × 0.55 × 0.29 mm; index ranges -25 ≤ h ≤ 25, -18 ≤ k ≤ 18, -18 ≤ l ≤ 19; total reflections 37401; independent reflections 4709; R int 0.0545; GOOF 1.108; R 1 = 0.0578, wR 2 = 0.1482; residual electron density -0.59/1.09 e/Å3. According to X-ray diffraction analysis data, in the molecules of compound 1, the antimony atoms have a distorted trigonal-bipyramidal coordination with the oxygen atoms of the carboxylate ligands in the axial positions. The Sb-C bonds (2.104(4)-2.114(8) Å) are shorter than the Sb-O distances (2.113(3) Å), the OSbO axial angle is 178.48(15)°, the CSbC angles are 109.7(2)°, 118.4(2)°, 131.8(3)°, while a significant increase in one of the angles is associated with the cis -conformation of the carboxylate ligands relative to the equatorial plane. The conformation of aryl ligands with respect to the equatorial plane [C3] is propeller. Structure 1 contains intramolecular Sb···O=C contacts between the antimony and oxygen atoms of the carbonyl groups of the carboxylate ligands, which are 3.089(3) Å. The formation of a spatial network in the crystal of compound 1 is due to the presence of weak hydrogen bonds with the participation of boron atoms of carboxylate ligands and fluorine of aryl ligands: B···H (3.19 Å) and F···B (3.45 Å). Complete tables of atomic coordinates, bond lengths, and bond angles are deposited at the Cambridge Structural Data Center (no. 2178731; deposit@ccdc.cam.ac.uk or http://www.ccdc.cam.ac.uk/data_request/ cif).