NEW TRIMETALLOSUPRAMOLECULAR RU(II) COMPLEXES CONTAINING FERROCENYLPYRAZOLE SUBUNITS

A series of bi-, tri-, and tetradentate acyclic redox-active ligands c ontaining one or two ferrocenylpyrazole subunits and one or two pyridi nes, differently organized, have been prepared. Starting from Ru(bpy)( 2)Cl-2, mono- and bi-Ru(ll) complexes have been obtained. Their study by NMR spectroscopy, electrochemistry, and molecular modeling shows im portant structural variations according to the relative position of th e ferrocenyl substitutent and of the coordination site. The ferrocenyl pyrazole seems to be a good moiety for electronic transfers and the in teraction between metallic centers depends strongly on the ligand stru cture.