Synthesis, crystal structure of a new tridimensional family of materials: LnCHA(H2O)(2)center dot 2.5H(2)O (Ln = Dy-Yb)

The slow diffusion in water through a H-tube of trivalent lanthanide ions w ith CHA(3-), where CHA(3-) stands for [C6H6(COO)(3)](3-), afforded single c rystals suitable for crystalline resolution. The crystal structure has been solved for the Er(III) compound and is reported here. The chemical formula is ErCHA(H2O)(2).2.5H(2)O and the space group of the crystalline structure is C2/c with a=13.3944(16) Angstrom, b=12.1501(9) Angstrom, c=15.9220(16) Angstrom, beta =92.089(13) and Z=8. The structure presents a complex tridim ensional network which can be described as the association of double-sheet network, via mu (2)-oxo bridges between Ln(3+) ions. The isostructurality o f the other compounds has been assumed on the basis of X-ray powder diagram s and elementary cell determination. The thermal properties of these compou nds have been studied and are reported hen. (C) 2001 Elsevier Science B.V. All rights reserved.