Synthesis and Characterization of Highly Luminescent Copolymers of Methyl Methacrylate and Eu‐Complexed 5‐Acryloxyethoxymethyl‐8‐hydroxyquinoline

Abstract

Highly luminescent Eu‐containing copolymers were synthesized through the copolymerization of Eu‐complex monomer featuring TTA and 5‐acryloxyethoxymethyl‐8‐hydroxyquinoline with MMA, and characterized by FT‐IR, UV–Vis, GPC, TGA, and DSC. The results indicated that the copolymers have not only a good solubility, thermal stability, and high glass transition temperatures, but also an intense red emission at 612 nm, corresponding to the 5D0 → 7F2 transition of Eu(III) ions under UV excitation. Compared with the Eu‐complex monomer, the Eu‐copolymers exhibited much higher luminescence lifetimes and efficiencies. Moreover, the luminescence intensities of the copolymers were much higher than those of the Eu‐complex/poly(methyl methacrylate) blend system at the same Eu content, and increased nearly linearly with an increase in the Eu content within 5.33 wt.‐%, and no significant concentration quenching phenomenon was observed at the Eu content up to 10.72 wt.‐%. In the blend system, however, the linear relationship between the luminescence intensity and Eu content was observed within 3.30 wt.‐%, and then the blend system showed typical emission concentration quenching on further increase in the Eu content. The improvement of the luminescence properties for the copolymers may be attributed to the special microenvironment, in which the Eu‐complex units are uniformly bonded to and surrounded by the polymer chain. These excellent photoluminescence properties may enable the novel copolymers to be used as pure red‐emitting materials.magnified image

Selective Recognition of Fe(III) in Aqueous Environment over Covalently‐Bonded Tb‐Complex‐Containing Fluorescent Porous Copolymer Microspheres

“…Unfortunately, most of the reported Ln‐complexes are unstable and sensitive to outside species due to the complexes can be easily disturbed by competing ligands, metal ions, acidic, or alkaline substances. A prevalent solution is incorporating Ln‐complexes into organic framework, polymers, inorganic, or hybrid matrices . Polymer microspheres are cost‐effective, easily available, and have convenient functionalization, which can provide hydrophobic environment to protect the Ln‐complexes from being disturbed by outside species.…”

Amphiphilic π-Conjugated Poly(m-phenylene) Photosensitizer for the Eu3+ Ion: The Role of Macromolecular Chain Aggregation on the Color Tunability of Lanthanides

“…Aromatic π-conjugated polymer-lanthanide hybrid materials are emerging as important candidates for the application in the field of light-emitting diodes. , These hybrid materials possess unique features of both polymers and lanthanide complexes, for example, mechanical and thermal stability, flexibility, and a film-forming tendency of polymers along with unique optical properties of the lanthanides such as sharp emission, long lifetime, and high quantum yield. − Additionally, the low absorption coefficients of the f -orbitals forbidden transitions in the lanthanides are also significantly improved by the strong absorbance characteristics of π-conjugated chains . Typically, two approaches are employed to make conjugated polymer–lanthanide hybrids: (a) blending of lanthanide complexes within π-conjugated polymers − and (b) anchoring the lanthanide ions via chemical linkage at the polymer backbone. − Although the physical blending technique has been successfully explored for poly( p -phenylene) and poly(fluorene) along with M 3+ ions (M = Eu, Er, and Yb), the phase separation of metal ions from the organic polymeric matrix is being noticed as an inherent limitation. , The chemical binding of M 3+ ions with π-conjugated polymer chains were achieved via either functionalization of conjugated backbones or anchoring groups with appropriate units such as carboxylate, bipyridyl, or diketone . Similarly functionalized π-conjugated oligomers of fluorene, thiophene, and phenylene moieties were also explored for Eu 3+ complexes. − However, one of the most important unanswered fundamental questions is: what is the advantage of the π-conjugated polymeric ligands over oligomers on the photosensitization of lanthanide ions?…”