Communication of Bichromophore Emission upon Aggregation – Aroyl‐<i>S,N</i>‐ketene Acetals as Multifunctional Sensor Merocyanines
Lukas Biesen, Lars May, Nithiya Nirmalananthan‐Budau, Katrin Hoffmann, Ute Resch‐Genger, Thomas J. J. Müller
Abstract
Aroyl-S,N-ketene acetal-based bichromophores can be readily synthesized in a consecutive three-component synthesis in good to excellent yields by condensation of aroyl chlorides and an N-(p-bromobenzyl) 2-methyl benzothiazolium salt followed by a Suzuki coupling, yielding a library of 31 bichromophoric fluorophores with substitution pattern-tunable emission properties. Varying both chromophores enables different communication pathways between the chromophores, exploiting aggregation-induced emission (AIE) and energy transfer (ET) properties, and thus, furnishing aggregation-based fluorescence switches. Possible applications range from fluorometric analysis of alcoholic beverages to pH sensors.