Reactions of tris[(2-methoxy)phenyl]antimony with acids in the presence of tertbutylhydroperoxide

In the reaction of tris(2-methoxyphenyl)antimony with trifluoroacetic and 3,4- dihydroxybenzoic acids in ether in the presence of tert-butylhydroperoxide in ether, tris(2- methoxyphenyl)antimony bis(trifluoroacetate) (1) and 4-carboxycatecholat-O,O'-tris(2-methoxyphenyl)antimony solvate with benzene (2) were synthesized, yielding 99% and 97%, respectively. According to X-ray structural analysis, the antimony atoms in complex 1 have a distorted trigonal bipyramidal coordination with the aryl substituents in the equatorial plane and the trifluoroacetate ligands in axial positions, with the CSbO axial angle being 171.54(5)°. Trifluoroalkyl substituents exhibit significant structural disorder, which is manifested in rather high values of thermal parameters of the fluorine atoms of these fragments. Relative to the Ar3Sb equatorial fragment, acylate substituents have a cis-orientation; the CSbC equatorial angles are 112.85(7), 119.10(7) and 127.82(7) with a sum of 359.77. In addition, complex 1 contains intramolecular contacts of the metal atom with the carbonyl oxygen atoms [Sb⋅⋅⋅O=C 3.447(6) and 3.475(7) Å] and oxygen atoms of the methoxy groups [Sb⋅⋅⋅OMe 3.057(6)3.164(7) Å]. The antimony atoms in complex 2 have coordination of a distorted tetragonal pyramid with two aryl substituents and two oxygen atoms of the catecholate ligand in the equatorial plane [Sb-C 2.1148(11), 2.1364(12) Å, and Sb-O 2.0351(9), 2.0860(8) Å] and the aryl ligand in the axial position [Sb-Сax 2.1073(12) Å]. The interaction of tris(2- methoxyphenyl)antimony with 2-sulfobenzoic and mesitylenesulfonic acids under similar conditions leads to formation of adducts (2-MeOC6H4)3Sb ∙ 3(2-MeOC6H4)3Sb=O ∙ 2H2O (3) and 2(2-MeOC6H4)3Sb ∙ 6(2- MeOC6H4)3Sb=O ∙ PhH (4). Complete tables of atomic coordinates, bond lengths, and valence angles of compounds 1–4 have been deposited with the Cambridge Crystallographic Data Centre [CCDC 2446111 (1), 2455807 (2), 2465816 (3), 2446130 (4), 2455883 (5); deposit@ccdc.cam.ac.uk; http://www.ccdc.cam.ac.uk].