Near-Infrared Luminescent PMMA-Supported Metallopolymers Based on Zn–Nd Schiff-Base Complexes

Metallopolymers for advanced sustainable applications

Since the development of metallopolymers, there has been tremendous interest in the applications of this type of materials. The interest in these materials stems from their potential use in industry as catalysts, biomedical agents in healthcare, energy storage and production as well as climate change mitigation. The past two decades have clearly shown exponential growth in the development of many new classes of metallopolymers that address these issues. Today, metallopolymers are considered to be at the forefront for discovering new and sustainable heterogeneous catalysts, therapeutics for drug-resistant diseases, energy storage and photovoltaics, molecular barometers and thermometers, as well as carbon dioxide sequesters. The focus of this review is to highlight the advances in design of metallopolymers with specific sustainable applications.

Crystal structures and luminescence properties of a D–A type CIEgen and its Zn(ii) complexes

A D–A type CIEgen with a near-planar molecular structure and its two Zn(ii) complexes with fluorescence selectivity for THF were obtained.

(E)-4-Methyl-N-((quinolin-2-yl)ethylidene)aniline as ligand for IIB supramolecular complexes: synthesis, structure, aggregation-induced emission enhancement and application in PMMA-doped hybrid material

Judicious structural design employing 2-quinolinecarboxaldehyde and 4-methylaniline was used to generate the Schiff base ligand (E)-4-methyl-N-((quinolin-2-yl)ethylidene)aniline (L). Five IIB complexes, namely, [ZnLCl₂] (1), [ZnL(NO₃)₂] (2), [ZnL(OAc)₂]₃ (3), [CdL(OAc)₂]₃ (4), and [HgLCl₂] (5) have been synthesized based on L. Single-crystal X-ray diffraction analysis indicates that complexes 1, 3 and 4 exhibit 3D networks, whereas 2 and 5 form 2D layers and 1D chains, respectively. TD-DFT calculations show a good correlation with the UV-vis absorption assigned to π → π* intraligand transitions. Furthermore, complexes 1-5 displayed strong greenish luminescent emissions (518-524 nm) in the aggregate state but weak emissions in solution (aggregation-induced emission enhancement), which may be due to the existence of C-HCl/O hydrogen bonding and ππ stacking interactions, resulting in restriction of intramolecular rotation (RIR). Variable-concentration ¹H NMR studies suggested that the aggregates undergo intramolecular changes in conformation due to intermolecular interactions. Moreover, the emission intensity and lifetime exhibited obvious increases induced by mechanical grinding and temperature reduction, which were also attributed to AIEE properties. Subsequently, complex 1 was incorporated into poly(methyl methacrylate) (PMMA), whereby 1-PMMA exhibited enhanced emission intensity (20-fold increase in comparison with that of 1), which offers opportunities for use in plastic greenhouses to increase leaf photosynthesis.

Single-component Eu3+–Tb3+–Gd3+-grafted polymer with ultra-high color rendering index white-light emission

Color-tuning to white-light (CIE coordinates of x = 0.322, y = 0.331; CCT of 5979 K; ultra-high CRI of 94) with a highly luminous efficiency (17.8%) was achieved for single-component Eu³⁺−Tb³⁺−Gd³⁺-grafted polymer Poly(MMA-co-2-co-3-co-4).

Different conjugated system Zn(ii) Schiff base complexes: supramolecular structure, luminescent properties, and applications in the PMMA-doped hybrid materials

Five Zn(ii) complexes with different conjugated systems were synthesized. Zn3 was incorporated into PMMA, creating a high performance material.

Lanthanide MOFs constructed based on a difunctional ligand with bimodal emission and Eu3+ doped Dy3+ materials: white emission and color tuning

A new strategy for multicolor materials by Dy and Eu cations.

Two samarium(iii) complexes with tunable fluorescence from in situ reactions of 2-ethoxy-6-((pyridin-2-ylmethylimino)methyl)phenol with Sm3+ ion

The solvothermal in situ C–C coupling reaction promoted by Sm³⁺ ion in Schiff base –CHN–CH₂– system is firstly reported, and two resulting temperature-dependent Sm(iii)-complexes 1 and 2 have different luminescent performance.

Near-infrared luminescence of Nd3+ and Yb3+ complexes using a polyfluorinated pyrene-based β-diketonate ligand

Highly efficient near-infrared emitting Nd³⁺ and Yb³⁺ complexes have been developed based on a new polyfluorinated pyrene-appended β-diketonate ligand.

Tunable luminescence of lanthanide (Ln = Sm, Eu, Tb) hydrophilic ionic polymers based on poly(N-methyl-4-vinylpyridinium-co-styrene) cations

Hydrophilic luminescent lanthanide-containing ionic polymers poly-[MVPS]₂[Ln(NO₃)₅] were prepared, which can be utilized as reversible colorimetric water-responsive sensors.

The first example of Tb3-containing metallopolymer-type hybrid materials with efficient and high color-purity green luminescence

In the obtained Tb³⁺-based efficient (Φ_overall = 76–83%) and high color-purity green luminescent 3@PMMA from doping and metallopolymer-type Poly(NBE-3), grafting endows a higher-concentration self-quenching.

Structure variations of a series of lanthanide complexes constructed from quinoline carboxylate ligands: photoluminescent properties and PMMA matrix doping

A series of lanthanide complexes constructed from H₂qldc are synthesized and the luminescence properties discussed.

PMMA-supported hybrid materials doped with highly near-infrared (NIR) luminescent complexes [Zn(L1)(Py)Ln(L2)3] (Ln = Nd, Yb or Er)

Based on the tris-β-diketonate hetero-binuclear complexes [Zn(L1)(Py)Ln(L2)3] (Ln = Nd, Yb or Er) with good NIR luminescent properties, a series of PMMA-supported doping hybrid materials PMMA@[Zn(L1)(Py)Ln(L2)3] exhibit improved properties.