Direct solid-phase synthesis of molecular heterooligonuclear lanthanoid-complexes.

Molecular lanthanoid complexes are highly valuable building blocks for a number of important technological applications, e.g. as contrast agents in magnetic resonance imaging (MRI) or as luminescent probes for bioassays. For the next generation of advanced applications based on molecular species, heterooligonuclear lanthanoid complexes with well-defined chemical and structural compositions are required. The great kinetic lability of trivalent lanthanoids so far prevents the realization of such molecular architectures with a universally applicable methodology. Here, we have developed functionalized molecular lanthanoid cryptates as monomeric building blocks which can be directly linked by standard solid-phase peptide synthesis to yield sequence-specific heterooligonuclear lanthanoid complexes. These molecular materials enable unique applications such as the generation of molecular codes with very convenient luminescence read-out.