Reversible Photoisomerization of Norbornadiene‐Quadricyclane within a Confined Capsule^†

Abstract

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 norbornadienequadricyclane (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 1 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.

Modifying and Taming Photoactive Compounds Using Synthetic Macrocycles as Supramolecular Hosts

“…These results were supported by 1 H NMR spectra and the measured diffusion constants. The primary objective was storing and releasing sunlight under sustainable green conditions and the reported results provided feasibility for combining green, sustainable and supramolecular chemistries in the framework of solar energy capture and release [41] …”

Multiconfigurational photodynamics simulations reveal the mechanism of photodecarbonylations of cyclopropenones in explicit aqueous environments

“…9–12 CO delivery can be activated through irradiation of a photoactive CO-releasing molecule (CORM). 13,14 Light enables spatiotemporal activation of different chemical processes, including energy storage in materials chemistry 15–26 and pro-drugs in drug delivery. 27–29 Reactive cycloaddends ( e.g.…”

“…[9][10][11][12] CO delivery can be activated through irradiation of a photoactive CO-releasing molecule (CORM). 13,14 Light enables spatiotemporal activation of different chemical processes, including energy storage in materials chemistry [15][16][17][18][19][20][21][22][23][24][25][26] and pro-drugs in drug delivery. [27][28][29] Reactive cycloaddends (e.g., cyclooctynes and 1,3-dipoles) can be accessed using light through a class of biorthogonal reactions known as 'photoclick chemistry.'…”

Driving the quadricyclane-to-norbornadiene isomerization by charge separation with perylenediimide as electron acceptor

“…In the current context, it is important that the QC oxidation potential is lower than that of NBD. [22][23][24][25] Major drawbacks of the NBD/QC couple stem, however, from their rather poor absorption across the visible region of the solar spectrum. Placing electronwithdrawing and/or electron-donating functionalities at the NBD double bonds by synthetic protocols helps circumvent this drawback.…”