Oxidation of tris(2-methoxyphenyl)antimony by tert-butyl hydroperoxide in the presence of 2-chloro-4-fluorophenol

Abstract

Oxidation of tris(2-methoxyphenyl)antimony by tert-butyl hydroperoxide in the presence of 2-chloro-4-fluorophenol in tetrahydrofuran or diethyl ether led to formation of tris(2-methoxyphenyl)antimony bis(2-chloro,4-fluorophenolate) (2-MeOC6H4)3Sb[OC6H3(Cl-2)(F-4)]2 (1), which, after recrystallization from a benzene-octane mixture, was characterized by IR spectroscopy and X-ray diffraction analysis. The IR spectrum of 1 contains bands characterizing vibrations of the SbC3 fragment (434 cm–1) and Sb–O bonds (536 cm–1), respectively. Crystallographic characteristics of 1 [C33H27Cl2F2O5Sb, M = 734.19; triclinic syngony, space group P-1; cell parameters: a = 8.41080(10) Å, b = 9.3964(2) Å, c = 19.6967(2) Å;  = 83.7850(10)°, β = 88.4990(10)°,  = 81.8700(10)°; V = 1531.86(4) Å3, Z = 2; calc = 1.592 g/cm3;  = 1.128 mm–1; F(000) = 736; collection area by 2q: 2.648–30.505°; –11 ≤ h ≤ 12, –13 ≤ k ≤ 13, –28 ≤ l ≤ 28; total reflections 41617; independent reflections 8942 (Rint = 0.0426); GOOF = 1.035; R-factor = 0.0215]. According to the X-ray diffraction data, the Sb−C distances in trigonal bipyramidal molecules 1 with electronegative ligands in axial positions are 2.0973(12)−2.0996(13) Å; the OSbO bond angle is 169.00(4)°. The Sb−O distances [2.0686(9) and 2.0850(10) Å] are comparable with those observed in similar triarylantimony diaroxides. The CSbC equatorial angles are 109.56(5)°, 124.53(5)°, 125.87(5)°, the sum of which is close to 360°. Such a large inequality in the equatorial angles is due to the presence of intramolecular contacts Sb∙∙∙OMe [3.000(3), 3.092(3), and 3.124 Å]. Complete tables of atomic coordinates, bond lengths and bond angles for structure 1 have been deposited with the Cambridge Crystallographic Data Centre (no. 2478179; deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk).