AMMONIUM HEPTACHLOROOXO-DIANTIMONATE(III), (NH4)3[SB2CL7O]

Each Sb atom of the title compound is formally psi-tetrahedral (AB3E) with covalent bonds to two terminal Cl atoms and one briding O atom. T hree directed secondary interactions to three additional symmetrically bridging Cl atoms give each Sb atom a roughly octahedral coordination geometry. The bridging arising from the secondary interactions produc es chains of [Sb2Cl4O]2 units which propagate along the unit-cell c ax is. The O, Cl(3) and Cl(4) atoms lie on crystallographic mirror planes , while Cl(5) resides on a twofold axis. The ammonium cations are hydr ogen bonded to the Cl and O atoms.