Coordination polymers constructed from oligonuclear nodes.

The node-and-spacer approach is widely employed in crystal engineering to construct coordination polymers. It consists of self-assembly processes involving mononuclear cationic species and exo-dentate ligands. We enlarged this strategy using preformed homo- and heterometallic complexes as nodes. The presence of two or more metal ions within a node leads to novel network topologies, as well as to new properties, arising from the intra- and internode interactions. This paper reviews some representative examples of coordination polymers obtained in our laboratory and constructed from: i) binuclear alkoxo-bridged complexes; ii) heterometallic 3d-3d' and 3d-4f complexes.