Multicomponent reaction-based discovery of pyrimido[2,1-b][1,3]benzothiazole (PBT) as a novel core for full-color-tunable AIEgens

The Hf(OTf)(4)-catalyzed three-component reaction (3CR) was employed as a powerful tool for facile access to a library of 23 pyrimido[2,1-b][1,3]benzothiazole (PBT)-based AIEgens with full-color tunability, solid-state fluorescence quantum yields of up to 86.8%, and high crystallizability. As atypical propeller-shaped molecules, PBT AIEgens were experimentally determined to dissipate the energy of the excited state via the rotation of the exocyclic carbonyl (ester/ketone) rather than the commonly known phenyl group. Theoretical calculations and crystallographic analysis of PBT AIEgens provide insights into their unique structure-property relationships and AIE mechanism from orbital and molecular aspects, respectively.

Automated summary

The Hf(OTf)(4)-catalyzed three-component reaction produced a library of 23 pyrimido[2,1-b][1,3]benzothiazole (PBT)-based AIEgens with full-color tunability, solid-state fluorescence quantum yields of up to 86.8%, and high crystallizability. Experimental and theoretical analyses demonstrated that PBT AIEgens dissipate energy through the rotation of the exocyclic carbonyl (ester/ketone) rather than the commonly known phenyl group, providing insights into their unique structure-property relationships and AIE mechanism.