IQUIR   05412
INSTITUTO DE QUIMICA ROSARIO
Unidad Ejecutora - UE
artículos
Título:
Biomimetic Cu, Zn and Cu2 complexes inserted in mesoporous silica as catalysts for superoxide dismutation
Autor/es:
DAIER, VERÓNICA; RIVIÈRE, ERIC; CAMÍ, GERARDO; PATRIARCA, MATÍAS; HUREAU, CHRISTELLE; PELLEGRI, NORA; DAIER, VERÓNICA; SIGNORELLA, SANDRA; RIVIÈRE, ERIC; PATRIARCA, MATÍAS; PELLEGRI, NORA; SIGNORELLA, SANDRA; CAMÍ, GERARDO; HUREAU, CHRISTELLE
Revista:
MICROPOROUS AND MESOPOROUS MATERIALS
Editorial:
ELSEVIER SCIENCE BV
Referencias:
Lugar: Amsterdam; Año: 2018 vol. 279 p. 133 - 141
ISSN:
1387-1811
Resumen:
Three CuZn-superoxide dismutase (SOD) functional mimics, [CuZn(dien)2(μ-Im)](ClO4)3 (1), [Cu2(dien)2(μ-Im)](ClO4)3 (2) (Im = imidazole, dien = diethylenetriamine), and [CuZn(salpn)Cl2] (3) (H2salpn = 1,3-bis(salicylideneamino)propane), were successfully inserted into the nanochannels of SBA-15 type mesoporous silica with retention of the silica mesostructure. X-ray absorption spectroscopic studies indicate that the encapsulated complexes keep unchanged the first-shell environment of Cu(II) and Zn(II) ions. Magnetic measurements suggest that the nanochannels constrain the geometry of the μ-imidazolate-Cu(II)2 core modifying the relative orientation of the two copper coordination planes. Confinement imposed by the silica nanochannels upon encapsulation of complexes 1 and 2 leads to stable hybrid materials at physiological pH with enhanced SOD activity relative to the free complexes. Unlike the imidazolato-bridged compounds, insertion of 3 in mesoporous silica leads to a less stable hybrid material exhibiting partial release into the aqueous solution and O2 ?− dismutation rate slower than the free complex. The covalent binding of a mononuclear Cu(dien)Im+ moiety to the mesoporous silica showed lower SOD activity than encapsulated imidazolato-bridged CuZn and Cu2 complexes. The results emphasize the positive effect of encapsulation on SOD activity of imidazolato-bridged dinuclear complexes.