Gain of Function Recyclable Photoswitches: Reversible Simultaneous Substitution and Photochromism Generation

11 August 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


The use of molecular photoswitches has spread to virtually every field of pure and applied chemistry because of the extraordinary level of control they provide over the behavior of matter at smallest scales. Photoswitches possess at least two different states with distinct structures and/or electronics and further functionalization of their core chromophore structures is needed to tailor them for a specific application. In this work we present a different concept for the generation and use of molecular photoswitches. It allows not only simultaneous establishment of photochromism and functionalization, but also full recyclability of a non-photochromic precursor material. Using a high-yielding and reversible ammonium salt formation, a functional group is introduced into a symmetric precursor while at the same time a strong electronic push-pull character is established in the structure. The resulting desymmetrization leads to efficient photoswitching capacity and the functional group can be fully removed subsequently by a simple heating step recovering the precursor for another functionalization round. We finally demonstrate feasibility of this concept over two consecutive closed loop functionalization/photoswitching/recovery steps. This concept offers great potential in any chemical research and application driven area but especially for the creation of responsive reprogrammable materials, no-background photoswitch labeling, and sustainable chemistry.


Chemical Recycling
Reversible Covalent Chemistry
Gain of Function

Supplementary materials

Supporting Information
Details of synthesis, conformational analysis, data and analysis of thermal isomerizations and stabilities, photoswitching properties, recycling methods, NMR and UV/Vis data.


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.