INQUIMAE   12526
INSTITUTO DE QUIMICA, FISICA DE LOS MATERIALES, MEDIOAMBIENTE Y ENERGIA
Unidad Ejecutora - UE
artículos
Título:
Zinc Porphyrin Metal-Center Exchange at the Solid Liquid Interface
Autor/es:
MATTHIAS FRANKE; HANS-PETER STEINRUECK; NORBERT JUX; FEDERICO J. WILLIAMS; FLORENCIA MARCHINI; OLE LYTKEN
Revista:
CHEMISTRY-A EUROPEAN JOURNAL
Editorial:
WILEY-V C H VERLAG GMBH
Referencias:
Lugar: Weinheim; Año: 2016 vol. 22 p. 8520 - 8520
ISSN:
0947-6539
Resumen:
Demetalation of zinc 5,10,15,20-tetraphenylporphyrin (ZnTPP) under acidic conditions and ion exchange with Cu2+ ions at neutral pH are both rapid reactions in the liquid medium. However, for ZnTPP monolayers adsorbed on a Au(111) surface exposed to aqueous solution, we find that, although ion exchange takes place rapidly as expected, demetalation does not occur, even at pH values as low as 0. Based on this, we conclude that metal center exchange on the surface does not proceed through a free-base porphyrin as an intermediate. Furthermore, once formed, CuTPP is stable on the surface and the reverse exchange from CuTPP to ZnTPP in the presence of Zn2+ ions could not be achieved. The preference for copper is so strong that even an attempt to exchange adsorbed ZnTPP with Ni2+ ions in the presence of traces of Cu2+ yielded CuTPP rather than NiTPP.