Raman excitation profiles for the complex [FeII FeIII(bpbpmp)(C2 H3O2)2](ClO4 ) (1), and its oxidized form, the new compound [FeIII FeIII(bpbpmp)(C2 H3O2)2](ClO4 )2 (2), are reported. H2bpbpmp is the proligand 2-bis[{(2-pyridylmethyl)-aminomethyl}-6-{(2-hydroxybenzyl)(2 -pyridylmethyl)}-aminomethyl]-4-methylphenol. For compound 1, the most enhanced vibrational mode in the Raman spectra is the nu(Fe-Ophen-terminal), observed at 608 cm-1. For compound 2, the nu(COphen-terminal), which corresponds to the band at 1276 cm-1, becomes the most enhanced one. These differences are ascribed to the changes in the electronic structure of the dinuclear phenolate bridged core upon oxidation. The phenolate bridge allows charge density transmission between the metal centers.
Resonance Raman spectroscopy; purple acid phosphatase; biomimetic analogue; mixed-valence; unsymmetrical ligand
