Helical Self‐Assembly and Fe3+ Detection of V‐Shaped AIE‐Active Chiral Tetraphenylbutadiene‐Based Polyamides.

Chiral aggregation‐induced emission (AIE) molecules have drawn attention for their helical self‐assembly and special optical properties. The helical self‐assembly of AIE‐active chiral non‐linear main‐chain polymers can produce some desired optical features. In this work, a series of V‐shaped chiral AIE‐active polyamides P1‐C3, P1‐C6, P1‐C12 and linear P2‐C3, P2‐C6, bearing n‐propyl/hexyl/dodecyl side‐chains, based on tetraphenylbutadiene (TPB), were prepared. All target main‐chain polymers exhibit distinct AIE characteristics. The polymer P1‐C6 with moderate length alkyl chains shows better AIE properties. The V‐shaped main‐chains and the chiral induction of (1R,2R)‐(+)‐1,2‐cyclohexanediamine in each repeating unit promote the polymer chains display helical conformation, and multiple helical polymer chains induce nano‐fibers helicity when the polymer chains aggregate and self‐assemble in THF/H2O mixtures. Simultaneously, the helical conformation polymer chains and helical nano‐fibers cause P1‐C6 produce strong circular dichroism (CD) signals with positive Cotton effect. Moreover, P1‐C6 could also occur fluorescence quenching response to Fe3+ selectively with a low detection limit of 3.48 μmol/L. [ABSTRACT FROM AUTHOR]