Enhanced luminescence for detection of small molecules based on doped lanthanide compounds with a dinuclear double-stranded helicate structure

Abstract

A novel family of lanthanide materials with a dinuclear double-stranded helicate structure Ln₂L₂(DBM)₄(OAc)₂ [Ln = Sm (1), Eu (2) Gd (3) and Yb (4)] constructed from β-diketonate (DBM = dibenzoylmethanide) and an auxiliary ligand Schiff base (H₂L = N,N′-bis(salicylidene)butane-1,6-diamine) was investigated. The structures of isostructural complexes 1–4 were determined by single-crystal and powder X-ray crystallography. The optical properties of these compounds could be enhanced by doping, allowing for doped materials with tunable visible and near-infrared emission. Subsequently, a multifunctional sensor was employed to detect CH₃COOH, as well as the poisonous ions Al³⁺ and Cr₂O₇²⁻. The notable quenching effect and luminescence-based color change showed that doped materials are promising fluorescence probes for the identification and detection of specific anions, cations and organic small molecules.