Work

Ester‐Aroyl‐S,N‐Ketene Acetals with Solid‐State Luminescence: AIEgens from Sequential Three‐Component Desymmetrization

Year: 2025

Type: article

Abstract: Di(hetero)aroyl dichlorides are desymmetrized upon sequential reaction with alcohols and 2‐methyl N ‐benzyl thiazolium salts within the course of a one‐pot three‐component reaction yielding ester‐substituted aroyl‐ S , N ‐ketene acetals under mild conditions in good yields. A prerequisite for the concise one‐pot process is the different nucleophilicity of the alcohols and in situ generated S , N ‐ketene acetals. The resulting compounds are merocyanines with dominant charge‐transfer absorption bands which are fluorescent in the solid state, but not in solution. In water/ethanol solvent mixtures of increasing water content, the water‐insoluble dyes display typical aggregation‐induced emission (AIE) characteristics. The water fraction inducing AIE as well as the emission color, and fluorescence quantum yield ( Φ f ) of the aggregated dyes can be controlled by the alcohol part of the ester moiety. Encapsulation into polystyrene nanoparticles can lead to a considerable increase of the fluorescence quantum yield Φ f to 30% as shown for a representatively chosen dye revealing the highest Φ f of 11% within the dye series in the water/ethanol mixtures and enabling the usage of these dyes as fluorescent reporters in aqueous environments.

Source: Chemistry - A European Journal

DOI: 10.1002/chem.202502071

Authors: Yannic Hartmann, Abdelouahad El Abbassi, Bernhard Mayer, Ute Resch‐Genger, Thomas J. J. Müller

Institutions: Heinrich Heine University Düsseldorf, Federal Institute For Materials Research and Testing

Language: English

Topic: Luminescence and Fluorescent Materials

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,640

Funders: Fonds der Chemischen Industrie, Deutsche Forschungsgemeinschaft