基于氟硼吡咯、氮杂氟硼吡咯光敏剂的均相光解水制氢研究
摘要
In this study, a series of BODIPY <bold>B<italic>n</italic></bold> (<italic>n</italic>=1-6) and Aza-BODIPY<bold> Aza-B<italic>n</italic></bold> (<italic>n</italic>=1-2) have been synthesized. After fully characterized by NMR, absorption, fluorescence and X-ray single-crystal diffraction, they were used as photosensitizers for the generation of hydrogen via the reduction of water using cobaloximes <bold>C<italic>n</italic></bold> (<italic>n</italic>=1-4) as the photocatalysts. Under optimized conditions (i.e., <bold>C1</bold> as catalyst, TEOA as sacrificial electron donor, a weak basic pH ~8.5, CH<sub>3</sub>CN/water ratio of 4:1, irradiation wavelength <italic>λ</italic>>420 nm), the TONs of hydrogen evolution for iodinated BODIPY (<bold>B4</bold>-<bold>B6</bold>) are 90, 101 and 164, while noniodinated BODIPY (<bold>B1</bold>-<bold>B3</bold>) and <bold>Aza-B<italic>n</italic></bold> (<italic>n</italic>=1-2) show no photocatalytic activity under the same reactions conditions. A reductive quenching pathway, namely, the intermolecular electron transfer from <bold>B<italic>n</italic></bold><sup>•</sup><bold><sup>-</sup></bold> (<italic>n</italic>=4-6) to the cobalt centers, in the photochemically driven step is possible for the hydrogen production, as evaluated from the electrochemical, spectra experiments and DFT calculations.