Synthesis and structure of tetraphenylantimony and triphenylantimony 4-oxybenzoates

Abstract

Solvate Ph3Sb[OC(O)C6H4(OH-4)]2 · 1/2Et2O (I) has been synthesized by the reaction between triphenylantimony and 4-oxybenzoic acid in the presence of hydrogen peroxide in diethyl ether. Tetraphenylantimony 4-oxybenzoate, which crystallizes from DMSO in the form of solvate Ph4SbOC(O)C6H4(OH-4) · DMSO (II), has been synthesized from pentaphenylantimony and triphenylantimony bis(4-oxybenzoate) or 4-oxybenzoic acid. According to X-ray diffraction data, an antimony atom in molecules of compounds I and II has a trigonal bipyramidal coordination. Crystals of compound I contain two crystallographically independent types of molecules (A and B). The Sb-C and Sb-O distances, the equatorial CSbC and axial OSbO angles are, respectively, 2.083(9)–2.103(8)A; 2.068(5), 2.128(5)A; 117.6(3)°–124.2(3)° and 171.5(2)° (IA); 2.103(9)–2.135(8)A; 2.086(5), 2.154(6)A;110.2(3)°–138.0(4)° and 174.8(2)° (IB). In compound II, Sb-C is 2.117(2)–2.175(2) A, Sb-O is 2.247(2) A, and CeqSbCeq and OSbCax angles are 110.89(9)°–133.30(9)° and 177.05(7)°, respectively. The Sb…O=C intramolecular contacts are 3.151(7), 3.153(8) A (IA), 2.985(8), 3.008(9) A (IB), and 2.975(5) A (II). Molecules IA and IB are conformation isomers, which differ from each other by the arrangement of carboxyl groups with respect to the equatorial plane.