Tetrahedral Assembly with Lanthanides: Toward Discrete Polynuclear Complexes

We report on the preparation of discrete 3D tetrametallic edifices containing trivalent lanthanides (Eu-Lu). Their formation is thermodynamically controlled through self-assembly with a new tripodal ligand L possessing short binding strands. X-ray crystallography shows that four nine-coordinate cations adopt a regular tetrahedral arrangement in the solid state. These remarkable, highly charged structures are maintained in solution, as demonstrated by NMR spectroscopy, ESI-MS and spectrophotometry. © Wiley-VCH Verlag GmbH & Co. KGaA, 2008.