Structure of pyridinium catena-μ-chloro-chloro(3,4,5,6-tetrachloropyrocatecholato)antimonate(III)

Abstract

Introduction. There are few reports on the determination of the crystal structures of pyrocatechol derivatives of main-group elements. In particular, the structure of only one Sb m derivative, antimony pyrogallate, is known (AuriviUius & Siirnstrand, 1976). We now report the structure of the title compound.Tetrachloropyrocatechol (0.01 mol) in 25 ml of dry methanol was added to SbC1 a (0.01 mol) in 25 ml of dry methanol and the mixture refluxed for 2 h under nitrogen. Pyridine (0.01 mol) was added slowly to the cooled reaction mixture. The precipitate was filtered, washed with dry methanol followed by petroleum ether and then dried. The product was recrystallized from acetonitrile to give crystals which melted at 482--483 K. Analysis gave Sb 22.6, C1 38.9%. Values required for [CsH6N]+[Sb(C6CI4Oz)C12] -are Sb 22.7, C139.1%.Single-crystal rotation and Weissenberg photographs of a crystal mounted along b were obtained and the cell dimensions deduced from them. These values were then used as the basis for a least-squares refinement of measurements from a Debye-Scherrer powder photograph.