Conformational effect on fluorescence emission of tetraphenylethylene-based metallacycles

Herein, we designed and constructed two metallacycles, 1 and 2, to illustrate the conformational effect of isomeric AIE fluorophores on the platform of supramolecular coordination complexes (SCCs). Specifically, the dangling phenyl rings in TPE units of the metallacycle 1 align completely outside the main cyclic structure, while in the metallacycle 2, these phenyl rings align half inside and half outside. The experimental results showed that two metallacycles exhibited different behaviors in terms of AIE fluorescence and chemical sensing, which could be attributed to the subtle structural difference of the TPE units. This work represents the unification of topics such as self-assembly, AIE, and chemical sensing, and further promotes the understanding for the structure-property relationship of isomeric AIE fluorophores.