CRYSTAL-STRUCTURE OF GADOLINIUM(III)-SULFITE TRIHYDRATE GD-2(SO3)(3)CENTER-DOT-3H(2)O

Gd-2(SO3)(3).3 H2O is obtained by passing gaseous SO2 through a suspension of Gd2O3 in H2O at room temperature until a clear solution is formed. Single crystals are obtained by heating to 70(2)degrees C for 6 days. The compound crystallizes in the triclinic space group P1 with a = 6.499(6), b = 6.621(3), c = 6.954(3) Angstrom, alpha = 110.71(5), beta = 90.54(3), gamma = 106.05(1)degrees and Z = 1. The two crystallographically different gadolinium atoms are both coordinated by eight oxygen atoms forming distorted square antiprisms. Gd(l) is coordinated by six O atoms of sulfite ligands and two O atoms of water, while Gd(2) is surrounded by seven O atoms of SO3 and one of H2O.Gd-O-bond lengths vary between 2.31(3) and 2.50(3) Angstrom.