Synthesis and structural features of aryl derivatives of antimony: [3-СF3C6H4]3Sb(OC6F5)2, Ph3Sb[OC(O)C6F5]2

Abstract

By oxidation of triarylantimony with tert-butyl hydroperoxide in the presence of pentafluorophenol or pentafluorobenzoic acid in diethyl ether, bis(pentafluorophenoxy)[tris(3-trifluoromethylphenyl)antimony] [3-CF3C6H4]3Sb[OC6F5]2 (1), bis(pentafluorobenzoato)-triphenylantimony Ph3Sb[OC(O)C6F5]2 (2) were obtained. Compounds 1 and 2 isolated after recrystallization from a benzene-octane mixture in the form of single crystals, were characterized by IR spectroscopy and X-ray diffraction analysis (XRD). According to XRD data, crystals 1 and 2 belong to the triclinic syngony, symmetry group P–1. The uncertainty factors for the refinement of structural data are R1 = 0,0272 (1), R1 = 0,0196 (2). In trigonal-bipyramidal molecules with electronegative ligands in axial positions, the Sb−C distances are 2,1059(15)−2,1079(14) Å for 1, and 2,1000(12)−2,1084(11) Å for 2; the OSbO bond angles take the values of 176,79(4)° (1) and 175,42(3)° (2). The Sb−O distances in 1 [2,0571(11) and 2,0679(11) Å] and are shorter than in 2 [2,1219(8) and 2,1543(8) Å]. The antimony atom in 2 coordinates the carbonyl oxygen atoms from the side of the maximum equatorial angle (138,04(4)°), while the intramolecular Sb∙∙∙O=C contacts are 2,9083(12) and 3,1885(13) Å. Complete tables of atomic coordinates, bond lengths and bond angles for the structures have been deposited with the Cambridge Crystallographic Data Centre (No. 2518894 (1), No. 2518899 (2), deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk).