Novel octadecanuclear copper(II)-lanthanoid(III) clusters. Synthesis and structures of [Cu(12)Ln(6)(mu 3-OH)(24)(O2CCH2CH2NC5H5)(12)(H2O)(16-)(mu 12-ClO4)][ClO4](17)center dot 16H(2)O (Ln(III)=Gd-III or Sm-III)

Two octadecanuclear clusters [Cu(12)Ln(6)(mu(3)-OH)(24)(O2CCH2CH2NC5H5)(12)(H2O)(16)(mu(12)-ClO4)][ClO4](17). 16H(2)O (Ln(III) = Gd-III or Sm-III) have been synthesized and characterized by X-ray structural analysis. The clusters are isostructural, crystallizing in the triclinic space group P (1) over bar with Z = 1. In each structure six Ln(III) are positioned at the vertices of an octahedron with twelve Cu-II at the midpoints of the edges of the octahedron. The 24 OH- groups act as mu(3) bridges each ligating one Ln(III) and two Cu-II. The octahedron encapsulates an unusual mu(12)-ClO4- anion of which each oxygen atom co-ordinates to three Cu-II at the axial positions. Ten of the C5H5N+CH2CH2CO2- ligands act in the mu-carboxylato-O,O' mode, while the other two act in the carboxylato-O,O' mode each chelating a Ln(III), resulting in different co-ordination environments for the Cu-II and Ln(III).