Furfural-Based Polyamides with Tunable Fluorescence Properties via Ugi Multicomponent Polymerization

Polyamides (PAs) are regarded as attractive fluorescent polymer materials due to their nontraditional intrinsic luminescence. In this work, a series of photoluminescence active PAs were prepared from renewable furfural derivatives via the Ugi four-component polymerization. Moreover, the fluorescence of dilute PA solutions can be accurately controlled by the intramolecular hydrogen bonding interactions using the furfural module as a switch, which was finally confirmed by DFT theory. As a probe, PAs can selectively recognize Fe2+ and Fe3+ among various metal ions by the fluorescence quenching effect. This protocol provides an efficient and moderate strategy for synthesizing biobased functional polymer materials with fluorescence properties, demonstrating high synthetic efficiency and high selectivity to Fe2+ and Fe3+.