On-demand acid-gated fluorescence switch-on in photo-generated nanospheres. Issue 37 (16th April 2020)

• Record Type: Journal Article
• Authors: Hooker, Jordan P.; Feist, Florian; Delafresnaye, Laura; Cavalli, Federica; Barner, Leonie; Barner-Kowollik, Christopher
• Is Part Of: Chemical communications. Volume 56:Issue 37(2020)
• Page Start: 4986
• Page End: 4989
• Publication Date: 2020-04-16
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1039/d0cc01557a
• Languages: English
• ISSNs: 1359-7345

Abstract

Abstract : Polymer particles are synthesized using a photo-active ortho -methyl benzaldehyde with a terminal alkyne for cross-linking. The reactive 1, 4-dihydronaphthalene at every cross-linking point undergoes aromatisation to a fluorescent naphthalene upon exposure to acid. Abstract : Herein, we introduce a fast, additive-free, ambient temperature photochemical approach – utilising the novel Diels–Alder cycloaddition of a photo-active ortho -methylbenzaldehyde ( o MBA) with a terminal alkyne – for preparing functional acid-sensitive profluorescent nano-/microspheres in one step. Not previously reported, the possibility of applying such a reaction in the context of particle synthesis provides new possibilities for particle design, where multi-step reactivity can be gated into distinct steps. First, a photochemically-gated particle formation step yields a material possessing a reactive, spring-loaded intermediate at every cross-linking point. A second, on-demand step to initiate fluorescence generation subsequently imparts the properties of the chemical transformation to the material itself. The synthesised particles are narrow-disperse with an average diameter ranging from 170–380 nm.