Synthesis and Х-ray diffraction study of bis[-oxo-tri(2-methylphenyl)antimony] solvate with benzene

Previously known bis [μ-oxo-tri(2methylphenyl)antimony] was synthesized by the reaction of tris (2-methylphenyl)antimony with tret -butyl hydroperoxide (1:1 molar ratio) in DMSO. A single crystal of the [(2 MeC6H4)3SbO]2·PhH (1) solvate was obtained by recrystallization from the mixture of benzene and heptane (3:1). The structure of solvate 1 has been investigated by X-ray diffraction study and IR spectroscopy. Absorption bands of hydroxy groups are not detected in the IR spectrum of solvate 1. Stretching vibrations of the Sb-O moiety and cyclic fragment υas(Sb2O2) are observed at 542-668 cm-1 and 653, 636 cm-1, respectively. Deformation vibrations δ(Sb2O2) are attributed to the band at 482 cm-1. According to X-ray data, the crystals of compound 1 are triclinic with the P -1 space group. Antimony atoms have a trigonal bipyramidal coordination. Two aryl substituents and the m2-bridged oxygen atom are in the equatorial plane of antimony atoms, and the third aryl substituent and the second m2-bridged oxygen atom are in axial positions. The sum of the CSbC and OSbC equatorial angles is 357.84º, and the OSbC axial angle is 162.89º. The cyclic Sb2O2 fragment of the molecule is flat. The Sb-C, Sb-O bond lengths and the SbOSb, OSbO valence angles are close to the previously reported unsolvated oxide. Structural organization in the crystals is characterized by the presence of intermolecular contacts C···H (2.893 Å) involving atoms of the phenyl rings of different molecules in the dimer oxide. Solvent molecules do not participate in the formation of short contacts and form a layer between the dimer oxide molecules bonded in a “chain” due to intermolecular bonds.