Aqueous synthesis of stable and luminescent flexible non-covalently assembled europium(iii) complexes–organoclay films

Abstract

In this paper, we report a novel lanthanide luminescent hybrid material that prepared by simple supramolecular co-assembly of aminoclay (AC), Eu(TTA)₃·2H₂O and deprotonated 4′-para-phenylcarboxyl-2,2′:6′,2′′-terpyridine (Na-Carb-Terpy) in aqueous system at room temperature. Bright red luminescence dominated by ⁵D₀ → ⁷F₂ transition (λ_em = 614 nm) of Eu³⁺ can be observed under appropriate UV light illumination. The hybrid material exhibits optimal luminescent properties coupled with good water dispersibility when the initial addition amount of AC and Terpy moieties is 4 : 1 in molar ratio. A consequence is that flexible, transparent and strong red-light-emitting thin film based on water-soluble polymer poly(vinyl alcohol) (PVA) has been successfully prepared, showing better luminescent properties than the hybrid material, as well as improved photo- and thermo-stability compared with pure Eu(TTA)₃·2H₂O.