title: Effect of asymmetry on the electronic delocalization in diiron and iron-cobalt mixed valence metallocenic compounds.
abstract: In this work, we report the synthesis and a study on the degree of electronic delocalization in the asymmetric mixed valence complexes [CpFe(C(8)H(6))Fe(C(8)H(7))](+), 3a(+), and [CpCo(C(8)H(6))Fe(C(8)H(7))](+), 3b(+), (Cp = C(5)Me(5), C(8)H(6) = pentalenyde, C(8)H(7) = hydropentalenyde, and = ((3,5(CF(3))(2)C(6)H(3))(4)B(-))). Electrochemical methods, (57)Fe Mössbauer spectroscopy, electronic spectroscopy, and electron paramagnetic resonance were used for this purpose. Although the anti conformation of the complexes precludes any metal-metal interaction, all the techniques employed show that 3a(+) is a electronic delocalized system, while 3b(+) behaves as two individual metallic centers with localized electron density.
authors.affiliation: Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus UAB, 08193 Bellaterra, Barcelona, España.
authors.forename: Y
authors.initials: Y
authors.lastname: Portilla
authors.forename: I
authors.initials: I
authors.lastname: Chávez
authors.forename: V
authors.initials: V
authors.lastname: Arancibia
authors.forename: B
authors.initials: B
authors.lastname: Loeb
authors.forename: J M
authors.initials: JM
authors.lastname: Manríquez
authors.forename: A
authors.initials: A
authors.lastname: Roig
authors.forename: E
authors.initials: E
authors.lastname: Molins