Crystal structure of sodium trans-bis(ethane-l, 2-diamine)- disulfitocobaltate(III) trihydrate

The crystal structure of the title compound, Na[Co(en)₂(SO₃)₂], 3H₂O, has been determined by single-crystal X-ray diffraction at 295(1) K and refined by least squares to a residual of 0·068 for 1890 ‘observed’ reflections. Crystals are monoclinic, P2₁/c, a 8·481(3), b 13·661(6), c 13·715(6) Å, β 106·91(3)°, Z 4. The asymmetric unit of the structure contains two independent anions, each located about a crystallographic centre of symmetry. <Co-S> is 2·26₇ Å, the longest Co-S distance so far reported in cobalt(III)/sulfite complexes.