Synthesis and Structural Characterization of Some Complexes of Hexa-coordinated Antimony

Abstract

The oxidation of triphenylantimony and triphenylphosphine by tert-butylhdroperoxide in the presence of catechol gives a new complex of a hexa-coordinated antimony, (C₆H₄O₂)SbPh₃(OPPh₃).⁷ In this complex triphenylphosphine oxide plays the role of the sixth ligand in a coordination sphere of an antimony atom of triphenylantimony o-phenylenedioxide. The compound was characterized by IR, ¹H NMR, ¹³C NMR, ³¹P NMR and X-ray single-crystal diffraction method. Crystal data for 7 at T = 293 K: a = 21.111(1) Å, b = 13.910(4) Å, c = 25.052(8) Å, β = 96.48(3)°, V = 7310₄(4) ų, Z = 8, D_calc = 1.380 g/cm³, μ = 0.839 mm⁻¹, space group C2/c. The geometry of the antimony atom in the synthesized complex is a distorted octahedron. Sixth coordination Sb-O(P) – 2.33 Å – is comparable with the sum of covalent radii of antimony and oxygen atoms, 2.20 Å. Five analogous complexes containing trimethyl(triethy1)antimony o-phenylenedioxide or 2.2.2-triphenyl-1.3.2-dioxas-tibolane and triphenylphosphine oxide or triphenylantimony o-phenylenedioxide and dimethylsulfoxide or pyridine oxide as a monodentate ligand were synthesized in the same manner. These compounds were also characterized by IR, ¹H ¹³C and ³¹P NMR.