Triethylammonium bis(2-oxido-2,2-diphenylacetato-κ2O1,O2)antimonate(III)

Abstract

The coordination around the Sb atom in the title compound, (C6H16N)[Sb(C14H10O3)2], is fourfold in a pseudo-trigonal-bipyramidal pattern in which one of the equatorial sites is occupied by the stereoactive lone pair of electrons. The four ligating atoms comprise the hydoxylate and carboxylate O atoms from two independent benzilate ligands, each of which forms a five-membered chelating ring, spanning an axial and an equatorial site about the Sb atom. The hydroxylate atoms occupy the two equatorial sites, and the carboxylate atoms are in the pseudo-axial sites; the O—Sb—O angle is 147.72 (5)°. One carboxylate group shows quite different bond lengths from those of the other group; one O atom is clearly the carbonyl atom and the other O atom the hydroxylate atom. In the other ligand, there is less distinction in the C—O bonds. This is presumably related to the carbonyl O atom being the acceptor atom of a strong N—H...O hydrogen bond, which links the ammonium cation to the Sb complex anion.