Europium-based metal-organic framework as a photocatalyst for the one-electron oxidation of organic compounds.
Lanthanide-based metal-organic frameworks (Ln-MOFs) are fascinating because of their versatile coordination geometry, unique luminescent and magnetic properties, and possible high framework stability to water. We synthesized nanosized europium-based MOF (Eu-MOF) particles and investigated the photoinduced electron transfer between the excited Eu-MOF nanoparticles and various organic compounds, such as aromatic sulfides and amines. From the time-resolved emission measurements, the bimolecular quenching rate constants of luminescence from the Eu(3+) ions in the MOF framework by electron donors were determined and explained in terms of the Marcus theory of electron-transfer reactions. Furthermore, spatially resolved emission quenching images obtained by confocal fluorescence microscopy revealed that small (large) quencher molecules quickly (slowly) and homogeneously (inhomogeneously) penetrate microsized Eu-MOF crystals. These observations led us confidently to assume the possibility that Eu-MOFs work as a size-selective photocatalyst for the one-electron oxidation of organic compounds.
The Institute of Scientific and Industrial Research (SANKEN), Osaka University, Mihogaoka 8-1, Ibaraki, Osaka 567-0047, Japan.
Jun Rye
JR
Choi
Takashi
T
Tachikawa
Mamoru
M
Fujitsuka
Tetsuro
T
Majima
D002384:Catalysis; D005063:Europium / Q000737:chemistry*; D008962:Models, Theoretical; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D009930:Organic Chemicals / Q000737:chemistry*; D010084:Oxidation-Reduction; D010777:Photochemistry / Q000379:methods*
D009930:Organic Chemicals; D005063:Europium