Crystal structure of ammonium cis-Tetraamminedisulfitocobaltate(III) trihydrate (a redetermination)

Abstract

The crystal structure of the title compound, NH4 [Co(NH3)4(SO3)2],3H2O, has been redetermined using diffractometer data at 295 K and refined by full-matrix least squares to a residual of 0.056 for 2068 'observed' reflections. Crystals are orthorhombic, P212121, a 10.978(4), b 17.552(7), c 6.828(3)Ǻ, Z 4. The redetermined structure provides accurate structural data for the cobalt environment; as well, it locates all hydrogen atoms and defines cations and water molecules un- ambiguously. Co-S are 2.224(2), 2.221(2) Ǻ. Co-N (trans to S) (1.993(6), 2.023(6) Ǻ) are longer than the mutually trans Co-N (1.970(7), 1.977(6) Ǻ); the difference in the former is a consequence of lattice hydrogen bonding.