title: Cyclodextrin-based systems for photoinduced hydrogen evolution.
abstract: Light-driven catalytic three component systems for the reduction of protons, consisting of a cyclodextrin-appended iridium complex as photosensitizer, a viologen-based electron relay, and cyclodextrin-modified platinum nanoparticles as the catalyst, were found to be capable of producing molecular hydrogen effectively in water, using a sacrificial electron donor. The modular approach introduced in this study allows the generation of several functional photo-active systems by self-assembly from a limited number of building blocks. We established that systems with polypyridine iridium complexes of general formula [Ir(ppy)(2)(pytl-R)]Cl (ppy, 2-phenylpyridine; pytl, 2-(1-substituted-1H-1,2,3-triazol-4-yl)pyridine) as photosensitizers are active in the production of H(2), with yields that under our experimental conditions are 20-35 times higher than those of the classical system with [Ru(bpy)(3)]Cl(2) (bpy, 2,2'-bipyridine), methyl viologen, and Pt. By investigating different photocatalytic systems, it was found that the amount of hydrogen produced was directly proportional to the emission quantum yield of the photosensitizer.
authors: Organic Chemistry, Institute for Molecules and Materials, Faculty of Science, Radboud University Nijmegen, Heijendaalseweg 135, 6525 AJ Nijmegen, The Netherlands.
authors: Nikos
authors: N
authors: Mourtzis
authors: Pablo Contreras
authors: PC
authors: Carballada
authors: Marco
authors: M
authors: Felici
authors: Roeland J M
authors: RJ
authors: Nolte
authors: René M
authors: RM
authors: Williams
authors: Luisa
authors: L
authors: de Cola
authors: Martin C
authors: MC
authors: Feiters