RARE-EARTH HYDROGENSULFATES M(HSO4)(3) (M = LA, CE-ND) - DERIVATIVES OF THE UCL3 TYPE OF STRUCTURE

Hydrogensulfates of the lighter lanthanides are obtained from the reac tion of the respective anhydrous sulfates with cone. sulfuric acid at 200 degrees C. According to X-ray single crystal determinations on La( HSO4)(3) (hexagonal, P6(3)/m, a = 945.64(9) pm, c = 590.87(5) pm), Ce( HSO4)(3) (a = 943.34(10) pm, c = 587.88(5) pm), Pr(HSO4)(3) (hexagonal , P6(3)/m, a = 939.8(1) pm, c = 584.82(9) pm) and Nd(HSO4)(3) (hexagon al, P6(3)/m, a = 935.67(8) pm, c = 582.36(4) pm) they all crystallize analogous to the UCl3 type of structure with nine-coordinate ions. The OH groups of the [HOSO3](-) ''tetrahedra'' build up channels parallel [00.1] typical for this type of structure. Hydrogen bonding, however, is only weak in these compounds.