Pradeep Anu, Varadharajan Ramkumar, Ramamurthy Vaidhyanathan
Department of Chemistry, University of Miami, Coral Gables, FL.
Photochem Photobiol. 2023 Mar;99(2):624-636. doi: 10.1111/php.13692. Epub 2022 Aug 30.
With the desire to develop a sustainable green method to store and release solar energy via a chemical reaction, we have examined the well-investigated norbornadiene-quadricyclane (NBD-QC) system in water. In this context, we have employed octa acid (OA) as the host that forms a capsule in water. According to H NMR spectra and diffusion constants, OA forms a stable 2:2 complex with both NBD and QC and 1:1:2 mixed complex in the presence of equal amounts of both NBD and QC. The photoconversion of NBD to QC within the OA capsule is clean without side reactions. In this case, OA itself acts as a triplet sensitizer. Recognizing the disadvantage of this supramolecular approach, in the future we plan to look for visible light absorbing sensitizers to perform this conversion. The reverse reaction (QC to NBD) is achieved via electron transfer process with methylene blue as the sensitizer. This reverse reaction is also clean, and no side products were detected. The preliminary results reported here provide "proof of principle" for combining green, sustainable and supramolecular chemistries in the context of solar energy capture and release.
出于通过化学反应开发一种可持续的绿色方法来存储和释放太阳能的愿望，我们研究了在水中经过充分研究的降冰片二烯-四环烷（NBD-QC）体系。在此背景下，我们使用了辛酸（OA）作为在水中形成胶囊的主体。根据核磁共振氢谱（¹H NMR）光谱和扩散常数，OA与NBD和QC均形成稳定的2:2络合物，并在等量的NBD和QC存在下形成1:1:2混合络合物。在OA胶囊内，NBD向QC的光转化过程纯净，无副反应。在这种情况下，OA本身充当三重态敏化剂。认识到这种超分子方法的缺点，我们计划在未来寻找可见光吸收敏化剂来进行这种转化。通过以亚甲基蓝作为敏化剂的电子转移过程实现了逆反应（QC转化为NBD）。该逆反应同样纯净，未检测到副产物。此处报道的初步结果为在太阳能捕获和释放的背景下结合绿色、可持续和超分子化学提供了“原理证明”。
