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

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 patterntunable 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.

Aroyl‐S,N‐Ketene Acetals: Luminous Renaissance of a Class of Heterocyclic Compounds

“…For these systems, too, the emission properties of the bichromophores can be improved by encapsulation in polystyrene particles (Figure 4, bottom). [77]…”

“…This has been exploited, as for bisaroyl‐ S , N ‐ketene acetals, to develop an alcohol sensor. For these systems, too, the emission properties of the bichromophores can be improved by encapsulation in polystyrene particles (Figure 4, bottom) [77] …”

“…They can be introduced into the sequence to allow for the greatest possible variance in bichromophore emitter structure (Figure 4, top). [77] Due to the high variance of the secondary emitters and acid chlorides used, a high systematic-method property diversity of the aroyl-S,N-ketene acetal bichromophores is obtained. This first manifests in further rainbow tuning of the solid-state emission colors, as already observed for the first and second generation aroyl-S,N-ketene acetals.…”

“… Synthesis of aroyl‐ S , N ‐ketene acetal‐based bichromophores via base‐mediated addition‐elimination‐Suzuki‐coupling‐one‐pot‐procedure Overview of investigated properties of aroyl‐ S , N ‐ketene acetal‐based bichromophores [77] …”

“…Synthesis of aroyl-S,N-ketene acetal-based bichromophores via base-mediated addition-elimination-Suzuki-coupling-one-pot-procedure Overview of investigated properties of aroyl-S,N-ketene acetal-based bichromophores. [77] emitting secondary emitter allows a broad diversification of the photophysical properties, so that the resulting bichromophores can be considered as multifunctional tools. Depending on the selected acid chloride and secondary chromophore, pronounced emission properties, in some cases also dual emission properties, are elicited or suppressed in solution.…”