A comparison of charge-transfer mechanisms at rotated disk electrode for biomimetic binuclear and tetranuclear oxo-manganese complex in aqueous solution

Autor(es)

Martin, Cibely S. ^[1] ; Teixeira, Marcos F. S. ^[1]

Afiliação do(s) autor(es)

^[1] Sao Paulo State Univ, UNESP, Fac Sci & Technol, BR-19060900 Prudente, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Inorganica Chimica Acta; v. 425, p. 76-82, JAN 30 2015.
• Citações Web of Science: 2

Resumo

Many high-valence multinuclear mu-oxo-bridged manganese complexes have been synthesized to mimic the active site of the natural enzymes. The electrochemical and kinetic parameters were determined for two mimicking complexes ({[}(Mn2O2)-O-IV(terpy)(2)(H2O)(2)](4+) and {[}(Mn4O5)-O-IV(terpy)(4)(H2O)(2)](6+)) by cyclic voltammetry and linear sweep voltammetry using a rotating disk electrode (RDE). Stability and kinetic behavior are directly related to mu-oxo bridges, where the mu-oxo-bridge provides a fast electron transition between metal centers due to stabilization of dx(2) - y(2) orbitals by the oxygen bond. On the other hand, when the dx(2) - y(2) orbitals are stabilized by aqua ligands by a coordination bond, a displacement of oxidation potential to more positive potential was observed. A shift of the potential to more negative values with increase in rotation rate was observed, which can be ascribed to a chemical step. The chemical step involves the dimerization process of the binuclear oxo-manganese complex to tetranuclear oxo-manganeses complex. (C) 2014 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 10/12524-6 - Estudo e caracterização da eletropolimerização de moléculas nanoestruturadas a base de schiff.
• Beneficiário: Cibely da Silva Martin Sonvesso
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 09/11079-1 - Utilização de complexo de oxo-manganês-terpiridina como material eletroativo no desenvolvimento de um sensor eletroquímico
• Beneficiário: Cibely da Silva Martin Sonvesso
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica