Tuning the delocalization degree in cyanide bridged trinuclear complexes

PABLO ALBORÉS; RICARDO BAGGIO; EVA RENTSCHLER; LUIS M. BARALDO

Ciudad del Cabo

Conferencia; 37th International Conference of Coordination Chemistry; 2006

In spite of the great variety of reported cyanide bridged complexes, there are not examples in the literature of a fully delocalized one. We have recently prepared1 a series of trinuclear compounds with the formula: [(CN)5FeIII(m-CN)RuIIL4(NC-m)FeIII(CN)5]-4, with L=pyridine,4-t-butylpyridine and 4-methoxypyridine. These complexes and their one electron reduced {FeII-RuII-FeIII} products belong to class II within the Robin-Day classification showing moderate electronic coupling between the terminal irons. Replacement, in the {FeII-RuII-FeIII} trimer compound, of the L ligand for 4-dimethylaminopyridine, dramatically changes its electronic spectrum. A detail analysis suggests that the ground state is delocalized (figure). The drastic narrowing of the MMCT and the high asymmetry towards lower energy are characteristics patterns of a delocalized system. Replacement of terminal Fe moieties by Os analogues also switches the electronic structure description to a delocalized picture. In this communication we present the structural and spectroscopic characterization of these trinuclear cyano bridged complexes exhibiting delocalized ground state characteristics in their electronic spectroscopy. The drastic narrowing of the MMCT and the high asymmetry towards lower energy are characteristics patterns of a delocalized system. Replacement of terminal Fe moieties by Os analogues also switches the electronic structure description to a delocalized picture. In this communication we present the structural and spectroscopic characterization of these trinuclear cyano bridged complexes exhibiting delocalized ground state characteristics in their electronic spectroscopy.   1. P.Alborés, L.D.Slep, T.Weyhermüller and L.M.Baraldo, Inorg.Chem. 43, 6762 (2004). 1. P.Alborés, L.D.Slep, T.Weyhermüller and L.M.Baraldo, Inorg.Chem. 43, 6762 (2004).