Bis-biphenylacrylonitrile bridged with crown ether chain: a novel fluorescence sensor for Fe3+ in aqueous media

Abstract

The design and synthesis of novel fluorescence sensors for Fe³⁺ in aqueous media have important prospects for practical applications. In this work, the novel bis-biphenylacrylonitrile bridged with crown ether chains 3a–3c were prepared in yields of 73–80%. Compounds 3a–3c exhibited high fluorescence in aqueous media based on the AIE effect. The sensing abilities for a series of metal ions suggested that the compound 3b possessed the selective detection for Fe³⁺ in aqueous media with strong fluorescence quenching. The detection limit of compound 3b for Fe³⁺ was 1.67 × 10⁻⁷ M and the sensing mechanism was proposed with the assistance of ¹H NMR and MS studies. Compound 3b displayed excellent fluorescence imaging properties with a sensing ability for Fe³⁺ in living cell systems, indicating the good application prospect for sensing Fe³⁺ in aqueous media and complex environments.