Lanthanide Coordination Polymers Research Articles

Statement of Retraction: Two lanthanide coordination polymers: treatment activity on the endometrial carcinoma by inhibiting the VEGF signaling pathway

Statement of Retraction: Two lanthanide coordination polymers: treatment activity on the endometrial carcinoma by inhibiting the VEGF signaling pathway

Integrated ratiometric luminescence sensing strategy based on encapsulation of guests in heterobinuclear lanthanide coordination polymer nanoparticles for glucose detection in human serum

Lanthanide coordination polymers (LnCPs) can be used as a host platform to encapsulate functional guest molecules for the construction of integrated sensing platforms. In this work, two guest molecules, rhodamine B (RhB) and glucose oxidase (GOx), were successfully encapsulated in a heterobinuclear lanthanide coordination polymer synthesized by self-assembly of Ce3+, Tb3+ and adenosine monophosphate (AMP) to form RhB&GOx@AMP-Tb/Ce. Both guest molecules show good storage stability and minimal leakage. The higher catalytic activity and stability of RhB&GOx@AMP-Tb/Ce is obtained due to the confinement effect compared to free GOx. RhB&GOx@AMP-Tb/Ce exhibits superior luminescence based on the internal tandem energy transfer process of the nanoparticles (Ce3+→Tb3+→RhB). Glucose can be oxidized in the presence of GOx to form gluconic acid and H2O2. Subsequently, Ce3+ in the AMP-Tb/Ce host structure can be oxidized by H2O2 to Ce4+, thereby interrupt the internal energy transfer process and cause ratiometric luminescence response. Benefiting from the synergistic effect, the smart integrated luminescent glucose probe exhibits a wide linear range (0.4–80 μM) and a low detection limit (74.3 nM) with high sensitivity, selectivity and simplicity, enabling the quantitative detection of glucose in human serum. This work describes a good strategy to construct an integrated luminescence sensor based on lanthanide coordination polymers.

An Ultra-stable Eu3+ Doped Yttrium Coordination Polymer with Dual-function Sensing for Cr(VI) and Fe(III) Ions in Aqueous Solution

The exploration of a dual-functional sensor is the key to effectively detect the Cr(VI) and Fe(III) cations in water, which is important to human health and environmental sustainability. Because of the phase stability and excellent luminescence, the rare-earth coordination polymers have great potential as dual-functional sensors. Here, we develop a Y0.91Eu0.09(H2O)2{C6H3(CO2)3}(MIL-92(Y):9%Eu3+)-based dual-function luminescent sensor on Cr(VI) and Fe(III), which exhibits excellent phase stability and dispersibility in water. The luminescence of MIL-92(Y):9%Eu3+ aqueous suspension quenches on Fe3+ with Stern-Volmer constant Ksv of 1.79 × 103 M-1 and limit of detection of 17 μM. The MIL-92(Y):9%Eu3+ aqueous suspension also has turn-off sensing ability towards Cr2O72- and CrO42- with Ksv values of 3.5 × 103 and 6.14 × 103 M-1, respectively. It has detection limitations of 10 and 5 μM on Cr2O72- and Cr2O72- ions, respectively.

A series of isostructural Ln-based coordination polymers: Crystal structure, luminescence sensing and color tuning

Compared with traditional detection methods, fluorescent sensors have many advantages in identifying metal ions. Herein, a new series of three-dimensional (3D) lanthanide coordination polymers (CPs) [Eu3(FDA)4(DMSO)2(NO3)(H2O)2]n (CP-1), [Tb3(FDA)4(DMSO)2(NO3)(H2O)2]n (CP-2) and [Eu3xTb3(1-x)(FDA)4(DMSO)2(NO3)(H2O)2]n (Eu/Tb-CP) based on 2,5-furandicarboxylic acid (H2FDA) were synthesized. Single-crystal X-ray diffraction indicated that both the CP-1 and CP-2 were isomorphic with a topology of {42.5}2{44.510.69.74.8} based on trinuclear second building units to form a 3D framework. Luminescence sensing experiments revealed that CP-1 has a good selection and recognition effect on Fe3+ (Ksv = 3.3 × 104 M−1, limit of detection (LOD) = 2.31 μM) and shows great potential as a luminescence sensor. Additionally, color tuning could be achieved by doped Eu3+ and Tb3+ into the reaction mixtures using the synergistic effect of their luminescent centers.

Statement of Retraction

This article refers to:RETRACTED ARTICLE: Lanthanide coordination polymer: crystal structure and application values on hypotension after anesthesia

Gelatinous lanthanide coordination polymer with aggregation-enhanced antenna effect for ratiometric detection of endogenous alkaline phosphatase

Aggregation-induced emission (AIE) and antenna effect (AE) are two significant behaviors that have attracted increasing attention. However, it is challenging to achieve the synergistic effect of AIE and AE in luminescent materials for more extensive applications. Here, four gelatinous Ln3+ coordination polymers (Ln-CPs) are synthesized by self-assembly of ciprofloxacin (CIP), adenosine monophosphate (AMP), and Ln3+ ions in aqueous medium. Encouragingly, a remarkable increase in the characteristic fluorescence of Ln3+ and a significant decrease in CIP are observed along with increasing concentration of Ln-CPs, which is attributed to the large aggregates formed by self-assembly that strictly constrain the intramolecular motions of antenna ligands, thereby achieving the aggregation-enhanced AE. More meaningfully, Eu-CP not only shows a rice-like morphology at high aggregation state, but also provides an opportunity for the selective detection of alkaline phosphatase (ALP). A new flower-like polymer is formed upon incubating Eu-CP with ALP, accompanied by the fluorescence quenching of Eu3+ and recovery of CIP, a ratiometric determination of ALP in the range of 0.1–6.0 U·L−1 is thus achieved. Additionally, ALP assay in human serum and bioimaging in living cells have been successfully performed. This research opens a new horizon for the fabrication of Ln3+-based luminescent materials with promising applications.

Lanthanide-acetate-phthalate coordination polymers: Energy transfer, white light emission and colorimetric titration

Motivated by the use of mixed sensitizers and photophysical properties of lanthanide coordination polymers, a new series of homometallic [LnIII(phth)(OAc)(H2O)] frameworks (LnIII = NdIII (I), SmIII (II), EuIII (III), GdIII (IV) and TbIII (V), H2phth = phthalic acid, HOAc = acetic acid) as well as three series of heterometallic [Tb1-xEux(phth)(OAc)(H2O)], [Tb1-yNdy(phth)(OAc)(H2O)] and [Eu1-zNdz(phth)(OAc)(H2O)] were synthesized and characterized. Single crystal structures of the homometallic frameworks were elucidated. The isostructure of all the synthesized frameworks was ensured and their solid-state photoluminescent and colorimetric properties were examined from which the sensitizing ability of phth2− and OAc-, their triplet state energies and substantial influence of non-radiative relaxation in III were revealed and discussed. Based on both spectroscopic and colorimetric perspectives, the inter-lanthanide energy transfers (TbIII-to-EuIII, TbIII-to-NdIII and EuIII-to-NdIII) and colorimetric titration in the heterometallic frameworks were investigated. The results are presented and discussed. In addition, potential of II (SmIII) as a stable, single-component white light luminophore was demonstrated.

Divalent Europium, NIR and Variable Emission of Trivalent Tm, Ho, Pr, Er, Nd, and Ce in 3D Frameworks and 2D Networks of Ln–Pyridylpyrazolates

The redox reactions of various lanthanide metals with 3-(4-pyridyl)pyrazole (4-PyPzH) or 3-(3-pyridyl)pyrazole (3-PyPzH) ligands yield the 2D network ∞2[Eu(4-PyPz)2(Py)2] containing divalent europium, the 3D frameworks ∞3[Ln(4-PyPz)3] and ∞3[Ln(3-PyPz)3] for trivalent cerium, praseodymium, neodymium, holmium, erbium, and thulium as well as ∞3[La(4-PyPz)3], and the 2D networks ∞2[Ln(4-PyPz)3(Py)] for trivalent cerium and thulium and ∞2[Ln2(4-PyPz)6]·Py for trivalent ytterbium and lutetium. The 18 lanthanide coordination polymers were synthesized under solvothermal conditions in pyridine (Py), partly acting as a co-ligand for some networks. The compounds exhibit a variety of luminescence properties, including metal-centered 4f–4f/5d–4f emission in the visible and near-infrared spectral range, metal-to-ligand energy transfer, and ligand-centered fluorescence and phosphorescence. The anionic ligands 3-PyPz− and 4-PyPz− serve as suitable antennas for lanthanide-based luminescence in the visible and near-infrared range through effective sensitization followed by emission through intra–4f transitions of the trivalent thulium, holmium, praseodymium, erbium, and neodymium. ∞2[Ce(4-PyPz)3(Py)], ∞3[Ce(4-PyPz)3], and ∞3[Ce(3-PyPz)3] exhibit strong degrees of reduction in the 5d excited states that differ in intensity compared to the ligand-based emission, resulting in a distinct emission ranging from pink to orange. The direct current magnetic studies show magnetic isolation of the lanthanide centers in the crystal lattice of ∞3[Ln(3-PyPz)3], Ln = Dy, Ho, and Er.

Anthracene-based lanthanide coordination polymer for the sensitive detection of 2-thiazolidinethione-4-carboxylic acid and temperature

An anthracene-based rare earth coordination polymer (CP) [Tb2Cl2(adip)(NMP)3(H2O)] (1) was prepared by solvothermal assembling of Tb3+ and 5,5′-(anthracene-9,10-diyl)diisophthalic acid (H4adip, NMP = N-methylpyrrolidone) and possesses a 3D framework and ligand-based blue emission. 1 could be used as a fluorescent probe to detect 2-thiazolidinethione-4-carboxylic acid (TTCA) and temperature with excellent selectivity, sensitivity and anti-interference ability. Between 0 and 10 μM concentration range of TTCA, the fluorescence quenching constant (Ksv) of 1 reaches 9.78 × 104 M−1 with the limit of detection of 92.6 nM. 1 could also be used as a temperature sensor within 0–60 °C. The maximum relative sensitivity (Sr) was calculated as 5.74% °C−1 at 60 °C and the temperature resolution (δT) is 0.013–0.003 °C corresponding to the above ambient temperature range. The sensitivities of 1 have reached the best level of reported chemical sensors so far. In addition, the mechanisms of fluorescence quenching were studied.

Chelating and pendant dual-antenna effect modulated ratiometric electrochemiluminescence system for lung cancer marker assay

Electrochemiluminescence of lanthanide coordination polymers (LCPs) has drawn researchers' torrential interest attributed to their congenital standout optical properties. Herein, a novel electrochemiluminescent (ECL) emitter LCPs Tb-norfloxacin (Tb-NFX) was firstly reported, which originated from that NFX transferred excited state energy to Tb3+ by chelating antenna effect. Moreover, a creative ratiometric ECL biosensor was established based on an emerging pendant antenna effect mechanism between luminol and Tb-NFX. Specifically, Tb-NFX was immobilized on the electrode surface and SiO2 nanostars@luminol was introduced onto the immunosensor by the sandwich-typed immunoassay. In view of this, the luminol transferred energy to the Tb-NFX and potential resolved ratiometric strategy was implemented for self-calibrated assay target. This work innovatively demonstrates that the development of new ECL luminophores through chelating antenna effect and the establishment of a dual-potential ECL ratio measurement strategy powered by pendant antenna effect are feasible, further extending the application of LCPs in ECL immunoassays and provides new directions for the construction of ECL ratio pairs.

Detecting phosphate using lysine-sensitized terbium coordination polymer nanoparticles as ratiometric luminescence probes.

Probes for detecting phosphate ions (Pi) are required for environmental monitoring and to protect human health. Here, novel ratiometric luminescent lanthanide coordination polymer nanoparticles (CPNs) were successfully prepared and used to selectively and sensitively detect Pi. The nanoparticles were prepared from adenosine monophosphate (AMP) and Tb3+, and lysine (Lys) was used as a sensitizer (through the antenna effect) to switch on Tb3+ luminescence at 488 and 544nm while Lys luminescence at 375nm was quenched because of energy transfer from Lys to Tb3+. The complex involved is here labeled AMP-Tb/Lys. Pi destroyed the AMP-Tb/Lys CPNs and therefore decreased the AMP-Tb/Lys luminescence intensity at 544nm and increased the luminescence intensity at 375nm at an excitation wavelength of 290nm, meaning ratiometric luminescence detection was possible. The ratio between the luminescence intensities at 544 and 375nm (I544/I375) was strongly associated with the Pi concentration between 0.1 and 6.0μM, and the detection limit was 0.08μM. The dual-emission reverse-change ratio luminescence sensing method can exclude environmental effects, so the proposed assay was found to be very selective. The method was successfully used to detect Pi in real water samples, and acceptable recoveries were found, suggesting that the method could be used in practice to detect Pi in water samples.

Structural metamorphosis and photophysical properties of thermostable nano- and microcrystalline lanthanide polymer with flexible coordination chains

ABSTRACT Luminescent lanthanide coordination polymer crystals (LCPCs) represent an area of growing interest in materials chemistry owing to their unique and tailorable functional properties. The LCPCs provide a high level of structural tunability, including size- and morphology-dependent properties; therefore, they are promising materials for next-generation phosphors in a wide range of applications such as light emitting diodes. Here, by controlling the morphology of thermostable europium coordination polymer crystals, [Eu(hfa)3(dpbp)]n, hfa: hexafluoroacetylacetonate and dpbp:4,4’-bis(diphenyl phosphoryl) biphenyl), we realized a novel red phosphor with narrow linewidth emission (FWHM = 7.8 nm). The obtained luminescent LCPCs with unique structures were characterized by X-ray diffraction (XRD), scanning transmission electron microscopy (STEM), dynamic light scattering (DLS) and thermogravimetric analysis. Among, them, size tunable crystalline polymer spheres were found to have high internal quantum efficiency (ex., IQE = 79%) and highly thermostability (>300°C), and to exhibit dispersibility in PMMA media. The obtained results on the structural tunability of these materials can be used for the development of synthesis techniques for nanoscale materials based on crystalline lanthanide-based coordination phosphors.

A multicenter lanthanide coordination polymer for ratiometric pesticide monitoring

Due to the increasing environmental and public health issues, efficient recognition and detection approaches for pesticides has attracted concerns worldwide. Herein, luminescent lanthanide coordination polymers (Ln-CPs) with tunable emissive centers are synthesized by simultaneously doping controlled amounts of Eu3+, Tb3+ and Gd3+ into the same framework. An optimized version of the multicenter Ln-CP (Eu0.048Tb0.052Gd0.9-CPBA) is prepared for 2D fingerprint recognizing pesticides. Additionally, the special “turn-on” response of ligand-based emission and “turn-off” response of Eu3+/Tb3+-based emission toward glyphosate (GPS) endow Eu0.048Tb0.052Gd0.9-CPBA with highly selective ratiometric sensing capability. The rapid, sensitive, selective and recyclable sensor for GPS provides a facile and adjustable synthetic approach for the development of multicenter ratiometric sensors. The real-time monitoring platform not only improves the sensitivity and selectivity but also holds great environmental significance.

Lanthanide(III) (Er/Ho) coordination polymers for a photocatalytic CO2 cycloaddition reaction.

Two new isostructural carboxylate-bridged lanthanide ribbons having the chemical formula [Ln2(4-ABA)6]n [4-ABA = 4-aminobenzoate, Ln: holmium (Ho) and erbium (Er)] were synthesized by a solvothermal method and fully characterized using multiple analytical, spectroscopic, and computational techniques. Single-crystal X-ray diffraction analysis reveals that both lanthanide coordination polymers (Ln-CPs) exhibit linear ribbon-like structures built up by dinuclear Ln2(4-ABA)6 units and bridged by carboxylate groups. Ln-CPs showed remarkably high thermal and chemical stabilities. Ho-CP and Er-CP exhibited similar band gaps of 3.21 eV and 3.22 eV, respectively, showing their photocatalytic ability under UV light. The photocatalytic activities of Ln-CPs were examined in the CO2 cycloaddition of epoxides to cyclic carbonates under solvent-free conditions, and full conversion (yields up to 99.9%) to the product was achieved. Ln-CP photocatalysts retained the same product yields over five consecutive cycles. Additionally, the experimental magnetic studies indicated that both Ln-CP crystals are antiferromagnetic at low T, which is confirmed by density functional theory calculations.

Single molecule magnet features in luminescent lanthanide coordination polymers with heptacoordinate Dy/Yb(III) ions as nodes.

Two sets of 1D/2D lanthanide coordination polymers with formulas of Ln(oqa)3·2H2O [Hoqa = 2-(4-oxoquinolin-1(4H)-yl) acetic acid, Ln = Dy (1), Yb (2)] and Ln(oaa)2(HCOO)(H2O) [Hoaa = 2-(9-oxoacridin-10(9H)-yl) acetic acid, Ln = Dy (3), Yb (4)] have been synthesized and their physical properties were investigated. All four complexes are constructed from seven-coordinate lanthanide ions and corresponding organic linkers. The lanthanide ions in 1 and 2 adopt a pentagonal bipyramid coordination geometry, whereas the coordination geometry of lanthanide ions in 3 and 4 can be described as a capped octahedron. Slow magnetic relaxation behaviors were observed in these four products at a zero/non-zero static magnetic field. Complexes 1, 2 and 4 exhibit the characteristic emission of Ln(III) ions, whereas complex 3 shows ligand-based emission. Bright yellow light emission was also observed when a voltage was applied, demonstrating the potential of 1 for application in light-emitting diodes (LEDs). Compounds 3 and 4 are the first examples of lanthanide complexes based on Hoaa ligands.

Synthesis, structure analysis and catalytic activity of two Ln-coordination polymers containing benzophenone-4,4′-dicarboxylate linker

Two Lanthanide-coordination polymers (Ln-CPs) were synthesized, characterized and used as heterogeneous catalysts for the acetalization of glycerol.

Highly photo- and triboluminescent lanthanide(iii) coordination polymers based on diphosphine dioxides containing azaheterocyclic linkers

Six thermostable one-dimensional Eu3+ and Tb3+ coordination polymers constructed from diphosphine dioxides bearing azaheterocyclic linkers show bright photo- and triboluminescence.

Layered lanthanide phosphonates Ln(2-qpH)(SO4)(H2O)2 (Ln = La, Ce, Pr, Nd, Sm): polymorphism and magnetic properties.

Polymorphic layered lanthanide coordination polymers provide opportunities to study the effect of intralayer and interlayer interactions on their magnetic dynamics. Herein we report a series of layered lanthanide phosphonates, namely, α-Ln(2-qpH)(SO4)(H2O)2 (Ln = Sm) (α-Ln), β-Ln(2-qpH)(SO4)(H2O)2 (Ln = Pr, Nd, Sm) (β-Ln) and γ-Ln(2-qpH)(SO4)(H2O)2 (Ln = La, Ce, Pr, Nd, Sm) (γ-Ln) (2-qpH2 = 2-quinolinephosphonic acid), which crystallize in monoclinic P21/c (α-Ln), triclinic P1̄ (β-Ln) and orthorhombic Pbca (γ-Ln) space groups, respectively. The structural differences between the β- and γ-phases lie not only in the intralayer but also in the interlayer. Within the layers, the Ln2O2 dimers are aligned parallel in the β-phase, but are non-parallel in the γ-phase. In the interlayer, there are π-π interactions between the quinoline groups in the α- and β-phases but not in the γ-phase. Magnetic studies reveal a field-induced slow relaxation of the magnetisation at low temperatures for compounds γ-Ce, β-Nd, and γ-Nd, and the impact of polymorphism on the magnetic dynamics of Nd(III) compounds is discussed.

Rational design and synthesis of scintillating lanthanide coordination polymers for highly efficient X-ray imaging

Rational design the energy bridge of organic ligands in scintillating lanthanide coordination polymers improved conversion efficiency to enhance characteristic emission of lanthanide cations, achieving high efficient X-ray imaging.

One-Dimensional Chain Viologen-Based Lanthanide Multistimulus-Responsive Materials with Photochromism, Photoluminescence, Photomagnetism, and Ammonia/Amine Vapor Sensing.

In this work, a series of novel multistimulus-responsive lanthanide coordination polymers {[LnL(H2O)4]Cl3·3H2O}n (Ln = Dy, Tb, Eu) constructed using a dicarboxylic acid viologen derivative L (L = N,N'-4,4'-bipyridiniodipropionate) and LnCl3·6H2O were prepared. All materials showed positive responses to UV light, and the photochromic phenomena accompanied by significant photoquenching of photoluminescence could be observed through a photoelectron transfer mechanism. Strikingly, the Dy analogue displayed photomagnetic behavior, as well as responded positively to small molecules of inorganic ammonia/organic amines. Furthermore, the good photoresponsive and ammonia/amine vapor-responsive properties of the Dy-based material were further fulfilled in dual-function papers involving erasable inkless printing and visual amine detection applications. This work aims to advance the development of multistimulus-responsive multifunctional materials incorporating viologen derivates and versatile lanthanide ions and further enriches the research in this field.