Improved luminescence properties by the self-assembly of lanthanide compounds with a 1-D chain structure for the sensing of CH3COOH and toxic HS− anions

Abstract

A novel family of lanthanide compounds with a 1-D chain structure [Ln₂L(TTA)₄(OAc)₂]_n [Ln = Sm (1), Eu (2) Gd (3) and Yb (4)] was constructed from β-diketonate (TTA = 2-thenoyltrifluoroacetone) and an auxiliary ligand Schiff base (H₂L = N,N′-bis(salicylidene)butane-1,6-diamine). The structures of the isostructural complexes 1–4 were determined via single-crystal and powder X-ray crystallography. The optical properties of these compounds could be simply enhanced using a doping method, enabling the doped materials with tunable visible and near-infrared emission. The quantum yields of the doped samarium and europium compounds reached 6.8% and 76.2%, respectively, which were higher compared with other previously reported studies. Subsequently, a multifunctional sensor was employed to detect CH₃COOH and poisonous HS⁻ anions. The notable quenching effect proved that this doped material is a promising fluorescence probe for the sensing of anions and organic small molecules with high identification ability and sensitivity. Moreover, the possible mechanism for luminescence sensing has been studied in detail.