North Carolina State University, 2620 Yarborough Drive, Campus Box 8204, Raleigh, NC 27695-8204, USA.
Dalton Trans. 2013 Oct 1;42(41):14883-91. doi: 10.1039/c3dt51849c.
We report the synthesis of four boron-dipyrromethene (BODIPY) sensitized cobaloxime complexes as structural models of light-driven proton reduction catalysts. The BODIPY chromophore is covalently linked to the cobaloxime via a pyridine molecule in the meso-position of the BODIPY. Electron withdrawing or donating substituents on the pyridine (e.g. chloro- or methyl-groups) allow a comparison of the influence of these substituents on cobaloxime-BODIPY interactions. This includes altering the overall stability of the complexes and tuning the catalytically relevant Co(II/III) redox couple over a range of 220 mV, which will assist in the design of future cobaloxime-chromophore complexes. All complexes were characterized using electrochemistry, electronic absorption and fluorescence spectroscopy. Additionally, we present crystal structures of the four new BODIPY-cobaloxime complexes and elucidate the influence of the structural modifications. We found that these compounds produce sub-stoichiometric quantities of hydrogen under standard photon-driven hydrogen evolving conditions.
我们合成了四个硼二吡咯亚甲基（BODIPY）敏化钴卟啉配合物，作为光驱动质子还原催化剂的结构模型。BODIPY 生色团通过 BODIPY 中位的吡啶分子与钴卟啉共价连接。吡啶上的吸电子或供电子取代基（例如氯或甲基基团）可以比较这些取代基对钴卟啉-BODIPY 相互作用的影响。这包括改变配合物的整体稳定性，并在 220 mV 的范围内调整与催化相关的 Co(II/III) 氧化还原对，这将有助于未来钴卟啉-生色团配合物的设计。所有配合物均通过电化学、电子吸收和荧光光谱进行了表征。此外，我们还呈现了四个新的 BODIPY-钴卟啉配合物的晶体结构，并阐明了结构修饰的影响。我们发现这些化合物在标准的光子驱动氢析出条件下产生亚化学计量的氢气。
