Benzo‐Tetrathiafulvalene‐ (BTTF‐) Annulated Expanded Porphyrins: Potential Next‐Generation Multielectron Reservoirs
Benzo‐Tetrathiafulvalene‐ (BTTF‐) Annulated Expanded Porphyrins: Potential Next‐Generation Multielectron Reservoirs
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苯并四硫富瓦烯（BTTF）环状扩张卟啉：潜在的下一代多电子储层
DOI：
10.1002/chem.202005021
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发表时间：
2021
期刊：
影响因子：
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通讯作者：
Furuta Hiroyuki
中科院分区：
文献类型：
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作者：
Jana Atanu;Ishida Masatoshi;Furuta Hiroyuki
合成了两个空间拥挤的苯并-四噻吩(BTTF) -环状扩展卟啉（BTTF7 - FandBTTF8）。详细的光物理研究揭示了它们固有的分子内电荷转移（CT）特性，源于部分电子从富含电子的TTF单元转移到相对缺乏电子的大环核。这一发现与之前报道的BTTF -环状[28]六葡萄蛋白（BTTF6）的图8构象形成对比，其中观察到典型的π -π *电子跃迁，从HOMO到LUMO。然而，在bttf7‐fandbttf8中的核心扩展使得低聚吡咯大环核心相对更缺电子，促进了有效的分子内CT过程。电化学对比研究表明，氧化区产生的电流与附着在大环核上的TTF单元的数量成正比。这项工作证明了通过在大环核心中增加TTF单元来控制分子内CT过程。这些扩展的卟啉的易发生多电子电化学氧化表明它们的行为像潜在的多电子储存库。
Two sterically crowded benzo‐tetrathiafulvalene (BTTF)‐annulated expanded porphyrins (BTTF7‐FandBTTF8) are synthesized. Detailed photophysical investigations reveal their intrinsic intramolecular charge transfer (CT) character, originated from partial electron transfer from electron‐rich TTF units to the relatively electron‐deficient macrocyclic core. This finding stands in contrast to what was observed in the previously reportedFigure‐of‐eightconformer of BTTF‐annulated [28]hexaphyrin (BTTF6), in which a typical π–π* electronic transition from HOMO to LUMO was observed. However, core expansion inBTTF7‐FandBTTF8makes the oligopyrrole macrocyclic cores relatively more electron‐deficient, facilitating the effective intramolecular CT process. Comparative electrochemical investigations reveal that the current generated at the oxidative region is directly proportional to the number of TTF units attached to the macrocyclic core. This work demonstrates the control of the intramolecular CT process through incremental addition of TTF units to the macrocyclic core. Facile multielectron electrochemical oxidations of these expanded porphyrins suggest that they behave like potential multielectron reservoirs.