Key indicators: single-crystal X-ray study; T = 140 K; mean (C-C) = 0.003 Å; R factor = 0.023; wR factor = 0.049; data-to-parameter ratio = 17.7.The coordination around the Sb atom in the title compound, (C 6 H 16 N)[Sb(C 14 H 10 O 3 ) 2 ], is fourfold in a pseudo-trigonalbipyramidal 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-HÁ Á ÁO hydrogen bond, which links the ammonium cation to the Sb complex anion.
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