Solution and Solid-State Emission Toggling of a Photochromic Hydrazone

Abstract

The proliferation of light-activated switches in recent years has enabled their use in a broad range of applications encompassing an array of research fields and disciplines. All current systems, however, have limitations (e.g., from complicated synthesis to incompatibility in biologically relevant media and lack of switching in the solid-state) that can stifle their real-life application. Here we report on a system that packs most, if not all, the desired, targeted and sought-after traits from photochromic compounds (bistability, switching in various media ranging from serum to solid-state, while exhibiting ON/OFF fluorescence emission switching, and two-photon assisted near-infrared light toggling) in an easily accessible structure.

Insight into 6π Electrocyclic Reactions of 1,8‐Dioxatetraene

“…Second, if some tactics to stabilize the 1,8‐dioxatetraene can be found, it would offer a chance to uncover the physical properties of this unexplored species. Ultimately, this research may lead us to discover stimuli‐responsive compounds …”

Light on Molecular Devices

“…In the recent past we have described examples of (supra)molecular switches, logic devices, machines and motors (see for instance the supramolecular pump shown in Figure 1), [1][2][3][4] as well as nanoparticles and porousm aterials endowed with light-activated functions. [5][6][7] In our research activity,w hich is supported in part by the European Research Council (https:// site.unibo.it/leaps), we takea dvantage of the full range of processes offered by molecular and supramolecular photophysics and photochemistry,w ith particularr egardt ol uminescence, photoinduced energy-, electron-and proton-transferp rocesses, and photoisomerization reactions.…”

“…These studies are focusedo nf undamental science, and are motivated by the search for innovative solutionstopractical problemsinc hemosensing, molecular delivery,catalysis, energy conversion and storage, and mechanical actuation atd ifferent length scales.In the recent past we have described examples of (supra)molecular switches, logic devices, machines and motors (see for instance the supramolecular pump shown in Figure 1), [1][2][3][4] as well as nanoparticles and porousm aterials endowed with light-activated functions. In this context, light is am ost attractive stimulus because it can be used both to "write" and "read" matter,i tc an be finely tuned in energy,t ime and space domains,a nd it can cause clean reactions.…”

The Many Ways to Assemble Nanoparticles Using Light

“…For example, azobenzenes and spiropyrans—probably the most commonly studied photoswitches—can be converted from a nonpolar to a polar form upon exposure to UV light, with the reverse reaction proceeding under visible light . These reversible isomerization processes are often accompanied by a change in the properties, e.g., electrical conductivity, color, fluorescence, or the ability to bind metal ions . However, there is a long way from individual molecules isomerizing in solution to robust, functional light‐responsive materials.…”