The fluorescence properties of 4′-Methoxychalcone derivates modified by substituents and investigation of lysosomal imaging

Three types of 4′-methoxychalcone derivatives Cha-1 ∼ Cha-9 with different electron-withdrawing or electron-donating substituents at different positions were synthesized and studied. When the A ring has a hydroxyl group at the 2-position, the strong electron-donating groups at the 4-position of the B ring was more conducive to the near-infrared and aggregation-enhanced emission (AEE) features of the compound than the electron withdrawing groups. The single-crystal analysis confirmed that the good planarity of the 4′-methoxychalcone derivatives favors their fluorescence quantum yields. Moreover, chalcone fluorophores with different fluorescence properties could be obtained by modulating substituent at the 2-position of A ring. In addition, Cha-9 was selected as the AEE luminogen to locate the lysosomes in HeLa cells. These results provided fundamental knowledge for the design and application of 4′-methoxychalcone derivatives of aggregation-induced emission (AIE) compounds.