Diaroyl-S,N-ketene Acetals: Red-Shifted Solid-State and Aggregation-Induced Emitters from a One-Pot Synthesis

Symmetric and unsymmetric diaroyl-S,N-ketene acetals can be readily accessed in consecutive syntheses in good to excellent yields by exploiting the inherent nucleophilic character of the methine position. Different aroyl-S,N-ketene acetals as well as acid chlorides yield a library of 19 diaroyl compounds with substitution and linker pattern-tunable emission properties, leading to a significant red-shift of emission in the solid and aggregated state, which was thoroughly investigated. Additionally, the stability of the luminescent aggregates is highly increased. In a follow-up one-pot procedure, pyrazolo-S,N-ketene acetals can easily be accessed employing a nucleophilic cyclocondensation.

Automated summary

Symmetric and unsymmetric diaroyl-S,N-ketene acetals can be easily synthesized in good yields by utilizing the nucleophilic character of the methine position. The resulting aroyl compounds exhibit tunable emission properties and increased stability of luminescent aggregates.