Unlocking Arene Phosphorescence in Bismuth-Organic Materials

Three novel bismuth-organic compounds, with the general formula [Bi2(HPDC)2(PDC)2]·(arene)·2H2O (H2PDC = 2,6-pyridinedicarboxylic acid; arene = pyrene, naphthalene, and azulene), that consist of neutral dinuclear Bi-pyridinedicarboxylate complexes and outer coordination sphere arene molecules were synthesized and structurally characterized. The structures of all three phases exhibit strong π-π stacking interactions between the Bi-bound PDC/HPDC and outer sphere organic molecules; these interactions effectively sandwich the arene molecules between bismuth complexes and thereby prevent molecular vibrations. Upon UV irradiation, the compounds containing pyrene and naphthalene displayed red and green emission, respectively, with quantum yields of 1.3(2) and 30.8(4)%. The emission was found to originate from the T1 → S0 transition of the corresponding arene and result in phosphorescence characteristic of the arene employed. By comparison, the azulene-containing compound displayed very weak blue-purple phosphorescence of unknown origin and is a rare example of T2 → S0 emission from azulene. The pyrene- and naphthalene-containing compounds both display radioluminescence, with intensities of 11 and 38% relative to bismuth germanate, respectively. Collectively, these results provide further insights into the structure-property relationships that underpin luminescence from Bi-based materials and highlight the utility of Bi-organic molecules in the realization of organic emission.

Double-emitting lanthanide metal-organic frameworks composed of Eu/Tb doping and ratiometric fluorescence detection of nitrofurazone

Lanthanide metal-organic frameworks (LnMOFs) have substantial potential in luminescence due to their unique antenna effect. Nevertheless, the single emission is susceptible to pseudo-signals caused by external environmental conditions, which significantly threaten the accurate measurement of the concentration. In this case, we prepared a dual-emission fluorescent probe {EuxTb1-x(NH2-BDC)3(DMF)4·2DMF}∞ (NH2-BDC = Diaminoterephthalic acid, DMF = N,N-dimethylformamide). The stable dual-emission signal provides a superior signal output for detecting nitrofurazone (NFZ), which is detected by the probe with excellent fluorescence for 0-10 μM NFZ. In the investigation of the detection mechanism, it is speculated that NFZ incorporates with probe to generate a novel complex. Furthermore, The UV absorption curves of the novel complexes and NFZ overlap extensively with those of the probe. The addition of NFZ attenuates the characteristic luminescence of Eu and Tb by competing for the absorption of the excitation light of the probe. The probe has exhibits rapid response, excellent sensitivity, visual detection and a meagre detection limit (LOD = 0.013 μM) for the detection of NFZ. This work not only broadens the application of LnMOFs in the field of ratiometric detection but also provides a favorable fluorescent probe for the quantitative detection of NFZ.

Turn-off luminescence sensing, white light emission and magnetic studies of two-dimensional lanthanide MOFs

The lanthanide metal organic framework compounds [Ln(BPTA)1.5(Bpy)]·0.5DMF (Ln = Y, Eu, Gd, Tb, Dy; 1a-5a) and [Ln(BPTA)1.5(Phen)]·0.5DMF (Ln = Y, Eu, Gd, Tb, Dy; 1b-5b) were prepared by employing 2,5-bis(prop-2-yn-1-yloxy)terephthalic acid (2,5-BPTA) as the primary ligand and 2,2'-bipyridine (1a-5a) and 1,10-phenanthroline (1b-5b) as the secondary ligands. Single-crystal structural studies on [Gd(BPTA)1.5(Bpy)]·0.5DMF (3a) and [Dy(BPTA)1.5(Phen)]·0.5DMF (5b) indicated that the compounds have a two-dimensional structure. The Y compound exhibits blue emission, and the other compounds exhibit emission in the expected regions (λex = 350 nm). White light emission was achieved by careful mixing of the red (Eu3+) and green (Tb3+) components in the blue emitting Y compound. Thus, Y0.96Tb0.02Eu0.02 (bpy) and Y0.939Tb0.06Eu0.001 (phen) were found to show white emission when excited using a wavelength of 350 nm. The introduction of N-N-containing ancillary ligands (i.e., bpy and phen) increased the overall quantum yield (QY) of white light emission to 31% and 43%, respectively. The high QY observed for the Tb and Eu compounds was found to be sensitive and selective for the fluorometric detection of azinphos-methyl pesticide and trinitrophenol (TNP) in an aqueous medium at the ppb level. The same behaviour was observed when utilising the compounds as onsite paper strip sensors. Their magnetic properties were also studied, revealing for the Tb and Dy derivatives slow relaxation of the magnetisation at low temperature. The present study highlights the usefulness of rigid π-conjugated molecules such as 2,2'-bipyridine and 1,10-phenanthroline in enhancing the many utilities of rare-earth-containing MOFs towards white light emission, the sensing of harmful and dangerous substances and magnetic properties.

Construction of High Quantum Yield Lanthanide Luminescent MOF Platform by In Situ Doping and Its Temperature Sensing Performance

Lanthanide luminescent MOF materials show excellent luminescent properties. However, obtaining lanthanide luminescent MOFs with high quantum yield is a challenging research. A novel bismuth-based metal-organic framework [Bi(SIP)(DMF)₂] was constructed by solvothermal method, utilizing 5-sulfoisophthalic acid monosodium salt (NaH₂SIP) and Bi(NO₃)₃·5H₂O. Thereafter, doped MOFs (Ln-Bi-SIP, Ln = Eu, Tb, Sm, Dy, Yb, Nd, Er) with different luminescent properties have been obtained by in situ doping with different lanthanide metal ions, among which Eu-Bi-SIP, Tb-Bi-SIP, Sm-Bi-SIP, and Dy-Bi-SIP have high quantum yield. What is special is that the doping amount of Ln³⁺ ions is very low, and the doped MOF can achieve high luminescence quantum yields. EuTb-Bi-SIP obtained by Eu³⁺/Tb³⁺ codoping and Dy-Bi-SIP exhibit good temperature sensing performance over a wide temperature range with the maximum sensitivity S_r of 1.6%·K^-1 (433 K) and 2.6%·K^-1, respectively (133 K), while the cycling experiments also show good repeatability in the assay temperature range. Finally, considering the practical application value, EuTb-Bi-SIP was blended with an organic polymer poly(methyl methacrylate) (PMMA) to produce a thin film, which shows different color changes at different temperatures.

Efficient Europium Sensitization via Low-Level Doping in a 2-D Bismuth-Organic Coordination Polymer

A new bismuth-organic compound containing 1,10-phenanthroline (phen) and 2,5-pyridinedicarboxylic acid (PDC) was synthesized and structurally characterized by single-crystal X-ray diffraction. The structure consists of 2-D {Bi(phen)(HPDC)(PDC)}n sheets wherein the PDC ligands bridge metal centers via three unique bonding modes. The 2-D sheets are further connected through strong hydrogen-bonding interactions to form a 3-D supramolecular network. The parent compound displayed yellow photoluminescence in the solid state at room temperature. Doping studies were undertaken to incorporate Eu3+ into the structure, statistically replacing Bi3+ in small quantities (1, 5, and 10 mol % Eu3+ relative to Bi3+). All three compounds displayed characteristic Eu3+ emission, with total quantum yields as high as 16.0% and sensitization efficiencies between 0.21 and 0.37 depending on the Eu3+ doping percentage.

Rapid synthesis of bismuth-organic frameworks as selective antimicrobial materials against microbial biofilms

Antibiotic resistance is a global public health threat, and urgent actions should be undertaken for developing alternative antimicrobial strategies and approaches. Notably, bismuth drugs exhibit potent antimicrobial effects on various pathogens and promising efficacy in tackling SARS-CoV-2 and related infections. As such, bismuth-based materials could precisely combat pathogenic bacteria and effectively treat the resultant infections and inflammatory diseases through a controlled release of Bi ions for targeted drug delivery. Currently, it is a great challenge to rapidly and massively manufacture bismuth-based particles, and yet there are no reports on effectively constructing such porous antimicrobial-loaded particles. Herein, we have developed two rapid approaches (i.e., ultrasound-assisted and agitation-free methods) to synthesizing bismuth-based materials with ellipsoid- (Ellipsoids) and rod-like (Rods) morphologies respectively, and fully characterized physicochemical properties. Rods with a porous structure were confirmed as bismuth metal-organic frameworks (Bi-MOF) and aligned with the crystalline structure of CAU-17. Importantly, the formation of Rods was a 'two-step' crystallization process of growing almond-flake-like units followed by stacking into the rod-like structure. The size of Bi-MOF was precisely controlled from micro-to nano-scales by varying concentrations of metal ions and their ratio to the ligand. Moreover, both Ellipsoids and Rods showed excellent biocompatibility with human gingival fibroblasts and potent antimicrobial effects on the Gram-negative oral pathogens including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum. Both Ellipsoids and Rods at 50 ​μg/mL could disrupt the bacterial membranes, and particularly eliminate P. gingivalis biofilms. This study demonstrates highly efficient and facile approaches to synthesizing bismuth-based particles. Our work could enrich the administration modalities of metallic drugs for promising antibiotic-free healthcare.

Blue-Emitting Ligand-Mediated Assembly of Rare-Earth MOFs toward White-Light Emission, Sensing, Magnetic, and Catalytic Studies

New lanthanide carboxylate compounds with two- (2D) and three-dimensional (3D) structures have been prepared by employing 2,5-bis(prop-2-yn-1-yloxy)terephthalic acid (2,5-BPTA) as an organic linker. The compounds, [Ln(C₁₄H₈O₆)(C₇O₃H₄)·2H₂O]·4(H₂O), Ln = Y, Pr, Nd, Sm, Eu, Gd, Tb, Dy and [Ln(C₇O₃H₄)₃·(C₃H₇ON)·(H₂O)]·2(H₂O)(C₃H₇NO), Ln = La, Ce, Pr, have two- and three-dimensional structures, respectively. In all compounds, lanthanide ions are connected together, forming a dimer, which is connected by the 2,5-BPTA ligand. In the two-dimensional structure, there are two 2,5-BPTA moieties present, and in the three-dimensional structure, there are three 2,5-BPTA moieties present. The lanthanide centers are nine-coordinated, the 2D structure has a tricapped trigonal prismatic arrangement, and the 3D structure has a monocapped distorted square antiprismatic arrangement. The Pr compound forms in both 2D and 3D structures, whose formation depends on the time of the reaction (2 days─2D and 5-6 days─3D). The ligand emits in the blue region, and using the characteristic emission of Eu³⁺ (red) and Tb³⁺ (green) ions, we achieve white light emission in the (Y_0.96Tb_0.02Eu_0.02) compound. The overall quantum yield for the white light emission is 28%. The strong green luminescence of the Tb³⁺-containing compound was employed to selectively sense the Cr³⁺ and Fe³⁺ ions in aqueous solution with limits of detection (LODs) at 0.41 and 8.6 ppm, respectively. The Tb compound was found to be a good heterogeneous catalyst for the Ullman-type O-arylation reaction between phenol and bromoarene with yields of 95%. Magnetic studies on the Gd-, Tb-, and Dy-containing compounds showed weak exchange interactions within the dimeric Ln₂ units. The present work demonstrates the many utilities of the rare-earth-containing MOFs, especially toward white-light emission, metal-ion sensing, and heterogeneous catalysis.

Electrochemical sensing of copper (II) ion in water using bi-metal oxide framework modified glassy carbon electrode

In this research, an electrochemical sensor was fabricated employing the metal-organic framework (MOF) deposited glassy carbon electrode (GCE) for the sensing copper ions in water with high sensitivity. The porous nanostructured MOF was characterized through Transmission electron microscope, scanning electron microscope and X-ray diffraction analysis. The Bi-MOF nanostructure deposited GCE (Bi-MOF/GCE) was fabricated by drop-casting a suspension of Bi-MOF in water on GCE surface. The performance of modified electrode in the presence and absence of heavy metal ions such as Cd²⁺, Hg²⁺ As³⁺, Pb²⁺ and Cu²⁺ was determined by the cyclic voltammetry in deionised water within the scan rate range of 25 and 300 mVs^-1. The Bi-MOF/GCE displayed highest anodic and cathodic peak current for Cu²⁺ ions than other metal ions, which was enhanced linearly within the scan rate range of 10-100 mV s^-1. Under the employed experimental conditions, the fabricated Bi-MOF/GCE based electrochemical sensor showed an outstanding routine in the determination of copper with a lowest sensing limit of 1 × 10^-5 M, wide linear range variation, strong interaction between metal ions and Bi-MOF. It has long-term stability and good reproducibility. The Bi-MOF/GCE electrode was successfully tested to detect Cu²⁺ in tap water with acceptable results.

Bismuth organic frameworks exhibiting enhanced phosphorescence

Bismuth-based organic frameworks (BiOFs) can display interesting phosphorescent properties, but the relationship between structure and optical activity remains underexplored. The structure-dependent phosphorescence properties in the BiOFs are investigated using different multidentate ligands. In-depth analysis of the luminescence properties confirms that the densely packed framework shows long-lasting phosphorescence at room temperature, owing to an efficient electron-hole separation. The combination of spectroscopic analysis and single-crystal structural analysis provides important insights into the emission control through BiOFs structural change, which can be a useful strategy for modulating the optical properties of various metal organic frameworks. Furthermore, taking the advantage of long-lasting phosphorescence, the potential usage as an eco-friendly photocatalyst is demonstrated.

Multifunctional luminescence sensing and white light adjustment of lanthanide metal-organic frameworks constructed from the flexible cyclotriphosphazene-derived hexacarboxylic acid ligand

Considering that cyclotriphosphazene polycarboxylic acid is a kind of organic ligand with fantastic structures and performances and the unique luminescence characteristics of rare earth ions, a series of porous lanthanide metal-organic frameworks (Ln-MOFs) (CH₃)₂NH₂[Ln₃(HCPCP)_1.5(CH₃COO)]·6DMA (Ln = Ce (1), Sm (2), Eu (3), Tb (4), HCPCP = hexa(4-carboxyphenoxy)cyclotriphosphazene, and DMA = N,N-dimethylacetamide) were synthesized with novel topological network structures. Compound 4 exhibited a sensitive recognition of -NO₂, and had a fluorescence quenching phenomenon for seven kinds of nitro aromatic compounds (NACs). In particular, it showed the best fluorescence response to 2,4,6-trinitrophenol (TNP) and 2,4-dinitrophenol (DNP), and the K_SV values were 2.86 × 10⁵ M^-1 and 8.21 × 10⁴ M^-1, and the limit of detection (LOD) values were 0.20 μM and 0.71 μM, respectively. At the same time, we successfully doped different concentrations of Eu³⁺ into compound 4 to obtain a series of doped Ln-MOF materials x%Eu³⁺@4 (x = 0.5, 2.5, 5, 7.5, 10, 15 and 20). With the increase of Eu³⁺ doping ratios, the characteristic peaks of Tb³⁺ and Eu³⁺ changed regularly, and the energy transfer from Tb³⁺ to Eu³⁺ ions occurred. By changing the excitation wavelength of the samples with different Eu³⁺ doping concentrations, a higher quality white light emitting material 7.5%Eu³⁺@4 (λ_ex = 340 nm) was finally obtained, with a CIE coordinate of (0.3268, 0.3212).

The Controllable Reconstruction of Bi-MOFs for Electrochemical CO2 Reduction through Electrolyte and Potential Mediation

Monitoring and controlling the reconstruction of materials under working conditions is crucial for the precise identification of active sites, elucidation of reaction mechanisms, and rational design of advanced catalysts. Herein, a Bi-based metal-organic framework (Bi-MOF) for electrochemical CO₂ reduction is selected as a case study. In situ Raman spectra combined with ex situ electron microscopy reveal that the intricate reconstruction of the Bi-MOF can be controlled using two steps: 1) electrolyte-mediated dissociation and conversion of Bi-MOF to Bi₂ O₂ CO₃ , and 2) potential-mediated reduction of Bi₂ O₂ CO₃ to Bi. The intentionally reconstructed Bi catalyst exhibits excellent activity, selectivity, and durability for formate production, and the unsaturated surface Bi atoms formed during reconstruction become the active sites. This work emphasizes the significant impact of pre-catalyst reconstruction under working conditions and provides insight into the design of highly active and stable electrocatalysts through the regulation of these processes.

Porous 3,4-di(3,5-dicarboxyphenyl)phthalate-based Cd2+ coordination polymer and its potential applications

Porous coordination polymers with organic aminium as one of the guest species possess a potential application in dye adsorption and white-light material manufacture. Polycarboxylic acid with multiple COOH substituents tends to form this type of porous material (with metal ion). Here the solvothermal self-assembly between Cd²⁺ and a hexacarboxylic acid creates such a porous material [(CH₃)₂NH₂]₆[Cd₃(L)₂]·5DMF·3H₂O (H₆L = 3,4-di(3,5-dicarboxyphenyl)phthalic acid) 1. Total potential guest accessible void volume in 3-D 1 is found to be 4327 Å³. Based on its better porous structure and stability, the ability of 1 to adsorb organic dyes is investigated. It has been proved that (i) 1 can selectively adsorb cationic dyes as Azure A (AA⁺) and/or Methylene Blue (MB⁺), rather than neutral and anionic ones; (ii) the maximum adsorption capacity is 698.2 mg·g^-1 for AA⁺ and 573.2 mg·g^-1 for MB⁺, respectively; and (iii) to the adsorption of AA⁺, it can be recycled for at least five rounds. Also, it is utilized to fabricate the while-light emitting material. Based on the blue-light emission of 1, the trace Eu³⁺ and Tb³⁺ ions are introduced into the pores of 1 successfully, obtaining a white-light emitting material Eu³⁺/Tb³⁺@1 (CIE chromaticity coordinates: (0.33, 0.32)). Meanwhile, Eu³⁺/Tb³⁺@1 is found to be a potential fluorescence photochromic material, showing a yellow-white-blue light emission. According to these investigations, the relationship between material structure and its adsorption property for dyes, the points that should be paid attention to in the construction of white-light emitting materials as well as the potential adsorption mechanism for dyes and rare earth ions are deeply discussed.

Bi(iii) MOFs: syntheses, structures and applications

The synthesis methods, structures and applications of Bi(iii)-based MOFs in catalysis, adsorption, fluorescence, etc. are reviewed.

A stable Ln(iii)-functionalized Cd(ii)-based metal–organic framework: tunable white-light emission and fluorescent probe for monitoring bilirubin

A novel anionic Cd(ii)-based metal–organic framework, H₂[Cd₉(DDB)₄(BPP)₄(H₂O)₁₄]·4H₂O·2DMA (1), was successfully obtained with a rigid carboxylate ligand 3,5-di(2′,4′-dicarboxylphenyl)benzoic acid (H₅DDB) and a flexible pyridyl ligand 1,3-bis(4-pyridyl)propane (BPP). Complex 1 contains two-dimensional (2D) honeycomb structures and one-dimensional (1D) chain structures. The adjacent 2D structures are linked by strong intermolecular hydrogen bonds to form an ABAB 3D supramolecular structure, where the 1D chain structures traverse the channels of the 2D structures. Due to the anionic framework, Ln(iii) ions (Ln = Eu and Tb) can be encapsulated in the framework of 1 by a post-synthetic modification process to obtain Ln(iii)@1, where 1.09Eu(iii)@1 (1a) and 0.658Tb(iii)@1 (1b) can be obtained by soaking complex 1 in a Eu(NO₃)₃·6H₂O or Tb(NO₃)₃·6H₂O aqueous solution for 48 h. The liquid-state emission spectra of Ln(iii)@1 can be tuned to be a white light emission by changing the Eu(iii)/Tb(iii) molar ratio in solution. Moreover, 1b can be used as a “turn-off” fluorescent probe for bilirubin with a low detection limit of 0.250 μM in phosphate buffer solution (pH = 7.4), which presents excellent sensitivity, high selectivity, and reusability. Furthermore, the devised fluorescent probe in serum also exhibits the fluorescence “turn-off” process with a low detection limit of 0.279 μM, and the recovery rate of bilirubin is 99.20–101.9%. The possible mechanisms of the fluorescence “turn-off” process can be explained by resonance energy transfer, and the weak interaction between 1b and bilirubin.

A novel anionic Cd(ii)-based metal–organic framework was used toencapsulateLn(iii) ions, which exhibits tunable luminescence and selective sensing of bilirubin.

Luminescence response mode and chemical sensing mechanism for lanthanide-functionalized metal–organic framework hybrids

This comprehensive review systematically summarizes the luminescence response mode and chemical sensing mechanism for lanthanide-functionalized MOF hybrids (abbreviated as LnFMOFH).

Synthesis, structural characterization, and luminescence properties of heteroleptic bismuth-organic compounds

The synthesis and photoluminescent properties of four bismuth-organic compounds, their lanthanide doped analogs, and an isostructural europium complex are reported.

The function of metal-organic frameworks in the application of MOF-based composites

In the last two decades, metal-organic frameworks (MOFs), as a class of porous crystalline materials formed by organic linkers coordinated-metal ions, have attracted increasing attention due to their unique structures and wide applications. Compared to single components, various well-designed MOF-based composites combining MOFs with other functional materials, such as nanoparticles, quantum dots, natural enzymes and polymers with remarkably enhanced or novel properties have recently been reported. To efficiently and directionally synthesize high-performance MOF-based composites for specific applications, it is vital to understand the structural-functional relationships and role of MOFs. In this review, preparation methods of MOF-based composites are first summarized and then the relationship between the structure and performance is determined. The functions of MOFs in practical use are classified and discussed through various examples, which may help chemists to understand the structural-functional relationship in MOF-based composites from a new perspective.

Ln-CPs constructed from unsymmetrical tetracarboxylic acid ligand: Tunable white-light emission and highly sensitive detection of CrO42-, Cr2O72-, MnO4- in water

A series of isostructural lanthanide coordination polymers (Ln-CPs), [Ln(Hbptc)(H₂O)₄]·H₂O [Ln = Er (1), Pr (2), Dy (3), Sm (4), Gd (5), Nd (6) and Tb(7); H₄bptc = 2,3,3',4'-biphenyl tetracarboxylic acid] have been isolated based on an unsymmetrical tetracarboxylic acid. Single-crystal X-ray diffraction analysis reveals that all CPs featured a two dimensional (2D) layer with (6, 6, 6)-connected 6³ topology. Luminescent spectra demonstrate that CPs 1-7 exhibit impressive UV-visible luminescence in the solid state at room temperature. More significantly, a single-component white-light material with International Commission on Illumination (CIE) coordinates of (0.335, 0.334) for 4 (Sm-CP), very closing to the pure white-light of (0.333, 0.333) was obtained by finely tuning of the excitation wavelength. In addition, the luminescent detection for anions of 7 is investigated. Fluorescence measurements show that 7 can detect oxoanion pollutants Cr₂O₇^2-, CrO₄^2-, and MnO₄^- anions in aqueous solutions with high selectivity and sensitivity, which suggests that the Tb-CP is a promising functional luminescence probe for toxic oxoanions. The possible mechanisms of the quenching effect were also discussed in detail.

Anion-directed assemblies of europium(III) coordination polymers based on 1H-benzimidazole-5,6-dicarboxylate: structures and luminescence properties

Two europium(III) coordination polymers (CPs), namely, poly[[diaquabis(μ₄-1H-benzimidazole-5,6-dicarboxylato-κ⁶N³:O⁵,O^5':O⁵,O⁶:O^6')(μ₂-oxalato-κ⁴O¹,O²:O^1',O^2')dieuropium(III)] dihydrate], {[Eu₂(C₉H₄N₂O₄)₂(C₂O₄)(H₂O)₂]·2H₂O}_n (1), and poly[(μ₃-1H-benzimidazol-3-ium-5,6-dicarboxylato-κ⁵O⁵:O^5',O⁶:O⁶,O^6')(μ₃-sulfato-κ³O:O':O'')europium(III)], [Eu(C₉H₅N₂O₄)(SO₄)]_n (2), have been synthesized via the hydrothermal method and structurally characterized. CP 1 shows a three-dimensional network, in which the oxalate ligand acts as a pillar, while CP 2 has a two-dimensional network based on a europium(III)-sulfate skeleton, further extended into a three-dimensional framework by hydrogen-bonding interactions. The structural diversity in the two compounds can be attributed to the different acidification abilities and geometries of the anionic ligands. The luminescence properties of 1 display the characteristic europium red emission with CIE chromaticity coordinates (2/3, 0.34). Interestingly, CP 2 shows the characteristic red emission with CIE chromaticity coordinates (0.60, 0.34) when excited at 280 nm and a near-white emission with CIE chromaticity coordinates (0.38, 0.29) when excited at 340 nm.

A down converting serine-functionalised NaYF4:Ce3+/Gd3+/Eu3+@NaGdF4:Tb3+ photoluminescent probe for chemical sensing of explosive nitroaromatic compounds

In this contribution, we explored a novel serine-functionalised NaYF₄:Ce³⁺/Gd³⁺/Eu³⁺@NaGdF₄:Tb³⁺ core–shell nanophosphor as a down-converting photoluminescent probe for efficient sensing of nitroaromatic explosives.

A white-light-emitting lanthanide metal–organic framework for luminescence turn-off sensing of MnO4− and turn-on sensing of folic acid and construction of a “turn-on plus” system

A white-light-emitting lanthanide MOF shows recyclable and dual-responsive sensing for MnO₄⁻ and folic acid in an aqueous system with high selectivity and sensitivity.

Assembly of four new cobalt coordination polymers modulated by N-coligands: sensitive and selective sensing of nitroaromatics, Fe3+and Cr2O72−in water

Four new Co-CPs (1to4) have been obtained with the modulation of N-coligands.2and3can serve as multi-responsive sensors for rapid and sensitive detection of nitroaromatics, Fe³⁺and Cr₂O₇²⁻in water.

Ultrasonic preparation of near-infrared emission cluster-based YbIII and NdIII coordination materials: Ratiometric temperature sensing, selective antibiotics detection and "turn-on" discrimination of l-arginine

Currently near-infrared (NIR) luminescence of lanthanide ions has received great attention because of their unique emissions in the near-infrared region (800-1700 nm). These NIR luminescent materials behave excellent applications in many fields such as sensors and probes in optical amplification, laser systems, biological systems and organic light-emitting diodes. In this work, two new near-infrared (NIR) emission three-dimensional (3D) Yb^III and Nd^III cluster-based coordination materials, namely {[Yb₂(L)₂(DMF)(H₂O)₄]·(DMF)₂ (H₂O)}_n (NIR-MOF 1) and [Nd(L)(DMF)₂]_n (NIR-MOF 2) (H₃L = terphenyl-3,4″,5-tricarboxylic acid) have been synthesized through the facile sono-chemical preparation methods. Both the near-infrared materials 1 and 2 have been characterized by single crystal X-ray diffraction, powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Further the mixed-lanthanide near-infrared emission material Nd_0.35Yb_0.65L (NIR-MOF 3) can also be prepared under the sono-chemical conditions. NIR-MOF 3 can be successfully applied as the ratiometric NIR-MOF-based thermometer, which should origin from the emission intensity ratio between Yb³⁺ (976 nm) and Nd³⁺ (1056 nm) in the temperature range of 308-348 K. Besides these, the micro-morphologies of NIR-MOF 1 can be deliberately tuned through different sono-chemical reaction factors (reaction time, reaction temperature and sono-chemical powers). These tuned nano-sized materials NIR-MOF 1 (100 W, 80 min) can be utilized as the fluorescent sensing material to distinguish furazolidone and sulfasalazine from other antibiotics. At the same time, NIR-MOF 2 can be applied as the first example of MOFs-based sensors for discriminating l-arginine from other amino acids through the "turn-on" mode in the near-infrared emission region.

Functional construction of a water-stable Tb-coordination polymer luminescent sensor for highly selective detection of picric acid in an aquatic environment

In order to achieve convenient and efficient detection of picric acid in a water environment, based on function-oriented strategy, we combine luminescence performance with recognition performance, taking into account the application conditions.

Synthesis, structure, fluorescence and electrochemical properties of a new Zn(ii)–organic framework constructed by a tricarboxylic acid ligand

A new efficient fluorescent sensor [Zn₃(L)(HL)(OH)(H₂O)₃]·H₂O (1) for detecting Cr₂O₇²⁻ anions has been synthesized. Moreover, compound 1 has been calcined to prepare a new electrocatalyst R-C@800 for HER.