64240 2025 eng 1 10 article Wiley-VCH Weinheim 1 -- -- -- AbstractDi(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 (Φf) 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 Φf to 30% as shown for a representatively chosen dye revealing the highest Φf of 11% within the dye series in the water/ethanol mixtures and enabling the usage of these dyes as fluorescent reporters in aqueous environments. Chemistry – A European Journal 0947-6539 10.1002/chem.202502071 urn:nbn:de:kobv:b43-642400 true journal-article http://creativecommons.org/licenses/by/4.0/ crossref doi-import false true 01.10.2025 Creative Commons - CC BY - Namensnennung 4.0 International Yannic Hartmann Abdelouahad El Abbassi Bernhard Mayer Ute Resch-Genger Thomas J. J. Müller eng uncontrolled Dye eng uncontrolled Fluorescence eng uncontrolled Aggregation eng uncontrolled Mechanism eng uncontrolled Signal enhancement eng uncontrolled Nano eng uncontrolled Particle eng uncontrolled Characterization eng uncontrolled Quantum yield eng uncontrolled Photophysics eng uncontrolled Probe eng uncontrolled Sensor eng uncontrolled Lifetime eng uncontrolled Polarity Analytische Chemie Ingenieurwissenschaften und zugeordnete Tätigkeiten 1 Analytische Chemie; Referenzmaterialien 1.2 Biophotonik Umwelt Chemie und Prozesstechnik Chemische Charakterisierung und Spurenanalytik Verlagsliteratur Datei für die Öffentlichkeit verfügbar ("Open Access") Wissenschaftliche Artikel der BAM Bundesanstalt für Materialforschung und -prüfung (BAM) https://opus4.kobv.de/opus4-bam/files/64240/Ester-Aroyl-S N-Ketene Acetals.pdf