Communication of Bichromophore Emission upon Aggregation – Aroyl‐S,N‐ketene Acetals as Multifunctional Sensor Merocyanines

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.