A similar reaction but employing TbCl3•6H2O in a basic MeCN/dmso solution affords the complex [Tb III 5O(OH)4(H3TBC [8])Cl(dmso)8(H2O)3]Cl3 (34; Fig. ). The metallic skeleton of 34 describes a distorted square-based pyramid. The Tb III ions in the square base are connected to each other via one µ4-O 2-ion and four µ-O(Ph) atoms, and to the apical Tb III ion through four µ3-OH -ions, one on each triangular face of the pyramid. The coordination sites of the metal ions are completed by the presence of several terminally bonded solvent molecules (dmso, H2O), with the dmso molecules occupying the cavities generated by each of the H3TBC [8] molecules. The Tb III ions are eight coordinate and in square antiprismatic {TbO8} or {TbO7Cl} geometries. The three protonated arms of the H3TBC [8] ligand are each H-bonding to one Cl -counter anion. The latter are also H-bonded to the terminally bonded H2O molecules. Perhaps surprisingly, the apical Tb III ion is not coordinated to the H3TBC [8] ligand at all, being connected to the rest of the molecule only through the four µ3-OH -ions. Its "exterior" square face is entirely comprised of four terminally ligated solvent molecules (3 x dmso, 1 x H2O), perhaps suggesting the possibility of further cluster growth by solvent substitution.