TY - JOUR A1 - Hartmann, Yannic A1 - El Abbassi, Abdelouahad A1 - Mayer, Bernhard A1 - Resch-Genger, Ute A1 - Müller, Thomas J. J. T1 - Ester‐Aroyl‐S,N‐Ketene Acetals with Solid‐State Luminescence: AIEgens from Sequential Three‐Component Desymmetrization N2 - 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. KW - Dye KW - Fluorescence KW - Aggregation KW - Mechanism KW - Signal enhancement KW - Nano KW - Particle KW - Characterization KW - Quantum yield KW - Photophysics KW - Probe KW - Sensor KW - Lifetime KW - Polarity PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-642400 DO - https://doi.org/10.1002/chem.202502071 SN - 0947-6539 SP - 1 EP - 10 PB - Wiley-VCH CY - Weinheim AN - OPUS4-64240 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - El Abbassi, Abdelouahad A1 - Krenzer, Julius A1 - Petrov, Eugene P. A1 - Biesen, Lukas A1 - Vasylyeva, Vera A1 - Merzenich, Sarah A1 - Resch-Genger, Ute A1 - Müller, Thomas J. J. T1 - Aroyl-S,N-ketene acetal-triarylamine bichromophores – intramolecular energy transfer and dual emission upon induced aggregation and encapsulation N2 - Aroyl-S,N-ketene acetal-based bichromophores are synthesized by a catalytic aryl amination and their photophysics are studied in the solid state, in ethanol–water mixtures inducing aggregation, and after encapsulation in polystyrene nanoparticles. The dye substitution pattern controls aggregation-induced emission and intramolecular energy transfer efficiency, resulting in single-band or dual fluorescence and a strong increase in fluorescence quantum yield upon particle encapsulation. KW - Fluorescence KW - Dye KW - Aggregation KW - Photophysics KW - Enhancement KW - White light emission KW - Energy transfer KW - Quantum yield PY - 2026 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-656700 DO - https://doi.org/10.1039/d5ra09361a SN - 2046-2069 VL - 16 IS - 11 SP - 10255 EP - 10260 PB - Royal Society of Chemistry (RSC) AN - OPUS4-65670 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -