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, 69451 Weinheim, Germany, 2008)