Синтез и кристаллическая структура бис(2-метилкарборанил-карбоксилата) трис(3-фторфенил)сурьмы

Abstract

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 Kα-radiation, λ = 0.71073 Å, graphite monochromator), the crystals are characterized by: C26H38B20F3O4Sb, M 809.52; monoclinic system, space group С2/c; cell parameters: a = 19.050(13), b = 14.441(9), c = 14.568(9) Å;  = 90, β = 98.51(2),  = 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; Rint 0.0545; GOOF 1.108; R1 = 0.0578, wR2 = 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 OSbО 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=С 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).