| Abstrakt: |
The methanesulfonates of trivalent lanthanides, Ln(CH3SO3)3·xH2O (Ln=Ce, Sm and Tb with x=2 and Ln=Yb with x=0), have been prepared by the reaction of methanesulfonic acid with the respective lanthanide oxide (CeO2, Sm2O3Tb4O7and Yb2O3) in the presence of water. In the reactions involving cerium and terbium oxides, hydrogen peroxide was used as reducing agent. Single crystals, suitable for X-ray examination, were obtained by slow evaporation of water-ethyl alcohol (50:50, v/v) solution. The isostructural tris(methanesulfonate)dihydrates of the trivalent Ce, Sm and Tb crystallize in the monoclinic system, space group P21/c(14), with Z=4, and cell parameters: a=948.9(l); b=1431.9(2); c=983.7(l) pm, β=91.22(2)° for Ce; a=938.1(l), b=1417.9(2), c=974.3(3) pm, β =91.19(2)° for Sm; and a=931.3(3), b= 1407.2(3), c=966.4(3) pm, β=91.09(3)° for Tb. Also the water-free ytterbium compound crystallizes in the monoclinic system, however the space group is P21(4), with two molecules per elementary cell. Its crystallographic parameters are a=979.8(5), b= 509.4(2), c=l 183.7(5) pm and β= 107.16(4)°. In all investigated compounds the methanesulfonate anion acts as a bidentate ligand, bridging two metallic centers to yield polymeric structures. |
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