Synthesis and structure of 2-oxo-bis[(aroxo)triarylantimony]

Μ2-Oxo- bis [(2,4-difluorophenoxo)triphenylantimony] (1), μ2-oxo- bis [(2-chloro-4-fluoro- phenoxo)triphenylantimony] (2), and μ2-oxo- bis [(2,5-difluorophenoxo)tris( para -tolyl)antimony] (3) have been obtained by the interaction of triphenyl- and tri( para -tolyl)antimony with 2,4-difluoro-, 2-chloro-4-fluoro-, and 2,5-difluorophenols in the presence of tert -butylhydroperoxide (1:1:1 mol.) in diethyl ether in yield up to 98 %. The compounds have been identified by IR spectroscopy and X-ray diffraction analysis. According to the X-ray diffraction analysis antimony atoms in compounds 1-3 have a distorted trigonal-bipyramidal coordination with oxygen atoms in axial positions. The molecules of compound 2 are centrosymmetric, the inversion center is represented by a bridging oxygen atom. The OSbO axial angles differ little and are 176.32(11)º, 179.00(10)º in 1; 178.6(4)º in 2; 176.3(2)º, 175.8(2)º in 3. The CSbC equatorial angle sums are 359.20(14)º and 359.12(14)º (1), 359.0(5)º (2), 358.4(3)º and 359.4(3)º (3). The Sb-O-Sb fragments of molecules 1-3 are bent; the SbOSb angles are 140.87(13)º, 141.0(10)º, 142.3(3)º. The average Sb-C distances are 2.111(3), 2.202(9), 2.110(8) Å in compounds 1-3, respectively. The Sb-O terminal bonds are longer than the Sb-O bonds with the bridging oxygen atom. Flat aryl rings are rotated around the Sb-C bonds in such a way as to minimize intra- and intermolecular interactions. The organization of molecules in the crystals of compounds is due to hydrogen bonds with the participation of fluorine atoms Н∙∙∙F 2.47-2.62 (1), 2.57 (2), 2.50-2.52 (3) Å, and is also due to the CH···π interaction of the rings of aryl and aroxide ligands. Complete tables of coordinates of atoms, bond lengths and valence angles are deposited at the Cambridge Crystallographic Data Center (No. 1986167 (1); No. 1976823 (2); No. 1976209 (3); deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk/data_request/cif).