Showing papers in "Inorganic Chemistry in 2018"
TL;DR: A Zn(II)-based fluorescent metal-organic framework (MOF) was synthesized and applied as a highly sensitive and quickly responsive chemical sensor for antibiotic detection in simulated wastewater and exhibited enhanced fluorescence derived from its highly ordered, 3D MOF structure as well as excellent water stability in the practical pH range of simulated antibiotic wastewater.
Abstract: A Zn(II)-based fluorescent metal–organic framework (MOF) was synthesized and applied as a highly sensitive and quickly responsive chemical sensor for antibiotic detection in simulated wastewater. The fluorescent chemical sensor, denoted FCS-1, exhibited enhanced fluorescence derived from its highly ordered, 3D MOF structure as well as excellent water stability in the practical pH range of simulated antibiotic wastewater (pH = 3.0–9.0). Remarkably, FCS-1 was able to effectively detect a series of sulfonamide antibiotics via photoinduced electron transfer that caused detectable fluorescence quenching, with fairly low detection limits. Two influences impacting measurements related to wastewater treatment and water quality monitoring, the presence of heavy-metal ions and the pH of solutions, were studied in terms of fluorescence quenching, which was nearly unaffected in sulfonamide-antibiotic detection. Additionally, the effective detection of sulfonamide antibiotics was rationalized by the theoretical comput...
242 citations
TL;DR: MOF-808 is one of the best colorimetric biosensors among the peroxidase mimics reported for H2O2, AA, and glucose detection, and is mainly ascribed to the Zr-OH(OH2) groups, which can be effectively shielded by gluconic acid, and subsequently the catalytic activity of MOF- 808 was significantly suppressed.
Abstract: Natural enzyme mimetics with high catalytic activity at nearly neutral pH values are highly desired for their applications in biological systems Herein for the first time a stable MOF, namely MOF-808, has been shown to possess high intrinsic peroxidase-like catalytic activity under acidic, neutral, and alkaline conditions As a novel peroxidase mimetic, MOF-808 can effectively catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine when H2O2 serves as oxidant, accompanied by a significant color variation in the solution The catalytic activity and the color variation were greatly dependent on H2O2 concentration, and thus MOF-808 can be applied to the colorimetric sensing of H2O2 The H2O2 detection limit is 45 μM, and the linear range is 10 μM to 15 mM In view of the significant inhibition effect produced by ascorbic acid, a facile and sensitive approach for colorimetric sensing of ascorbic acid was successfully established The AA detection limit is 15 μM, and the linear range is 30–1030 μM Further
227 citations
TL;DR: La:HfO2 appears to be a material with a broad window of process parameters, and accordingly, by optimization of the La content in the layer, it is possible to improve the performance of the material significantly.
Abstract: Recently simulation groups have reported the lanthanide series elements as the dopants that have the strongest effect on the stabilization of the ferroelectric non-centrosymmetric orthorhombic phas...
211 citations
TL;DR: The photocatalytic behaviors of the nanoparticles were investigated by removal and degradation of different organic dyes under the UV irradiation, and indicated a highest degradation for acid black 1 of 85.7% in 110 min.
Abstract: In the present study, Tl4CdI6 nanostructures were synthesized via a facile sonochemical method. The effect of molar ratio of TlI to CdI2, reaction time, power of sonication, and the capping agents was investigated on morphology, size, and purity of the products. The as-prepared nanomaterials were characterized by X-ray diffraction, X-ray energy dispersive spectroscopy, field emission scanning, transmission electron microscopy, and Raman spectroscopy. The optical property of Tl4CdI6 nanoparticles was investigated by ultraviolet–visible spectroscopy (UV–vis), and the band gap was estimated about 2.82 eV. The photocatalytic behaviors of the nanoparticles were investigated by removal and degradation of different organic dyes under the UV irradiation. The results indicated a highest degradation for acid black 1 of 85.7% in 110 min. This sample was selected as an optimum sample for photocatalytic application.
182 citations
TL;DR: A data-driven model was developed, which chose suitable elements to reduce the enthalpy of formation and hence to increase the chance of single phase formation, and provides a simple approach to find new high-entropy functional materials in the largely unexplored multielement chemical space.
Abstract: High-entropy compounds with compositional complexity can be designed as new thermoelectric materials. Here a data-driven model was developed, which chose suitable elements to reduce the enthalpy of formation and hence to increase the chance of single phase formation. Using this model, two high-entropy sulfides were designed, metallic Cu5SnMgGeZnS9 and semiconducting Cu3SnMgInZnS7. They were then successfully fabricated as single-phase dense ceramics with homogeneously distributed cations, and their phase stability and atomic local structures were investigated using density functional theory calculations. Finally, a zT value of 0.58 at 773 K was obtained for Cu5Sn1.2MgGeZnS9, where additional Sn was used to tune the carrier concentration. This work provides a simple approach to find new high-entropy functional materials in the largely unexplored multielement chemical space.
179 citations
TL;DR: Luminescent investigations demonstrate that the stable CH3NH3PbBr3@MOF-5 composites not only featured excellent sensing properties with respect to temperature changes from 30 to 230 °C but also exhibited significant selective luminescent response to several different metal ions in aqueous solution.
Abstract: The stability issue of organometallic halide perovskites remains a great challenge for future research as to their applicability in different functional material fields. Herein, a novel and facile two-step synthesis procedure is reported for encapsulation of CH3NH3PbBr3 perovskite quantum dots (QDs) in MOF-5 microcrystals, where PbBr2 and CH3NH3Br precursors are added stepwise to fabricate stable CH3NH3PbBr3@MOF-5 composites. In comparison to CH3NH3PbBr3 QDs, CH3NH3PbBr3@MOF-5 composites exhibited highly improved water resistance and thermal stability, as well as better pH adaptability over a wide range. Luminescent investigations demonstrate that CH3NH3PbBr3@MOF-5 composites not only featured excellent sensing properties with respect to temperature changes from 30 to 230 °C but also exhibited significant selective luminescent response to several different metal ions in aqueous solution. These outstanding characteristics indicate that the stable CH3NH3PbBr3@MOF-5 composites are potentially interesting for...
167 citations
TL;DR: The present study clearly suggests that low-cost Co(OH)2 platelets are the most crucial semiconductors to provide a new p-n heterojunction photocatalyst for photocatalytic H2 and O2 production on the platform of ZnCr LDH.
Abstract: Photocatalytic generation of H2 and O2 by water splitting remains a great challenge for clean and sustainable energy. Taking into the consideration promising heterojunction photocatalysts, analogous energy issues have been mitigated to a meaningful extent. Herein, we have architectured a highly efficient bifunctional heterojunction material, i.e., p-type Co(OH)2 platelets with an n-type ZnCr layered double hydroxide (LDH) by an ultrasonication method. Primarily, the Mott–Schottky measurements confirmed the n- and p-type semiconductive properties of LDH and CH material, respectively, with the construction of a p–n heterojunction. The high resolution transmission electron microscopy results suggest that surface modification of ZnCr LDH by Co(OH)2 hexagonal platelets could form a fabulous p–n interfacial region that significantly decreases the energy barrier for O2 and H2 production by effectively separating and transporting photoinduced charge carriers, leading to enhanced photoreactivity. A deep investigat...
149 citations
TL;DR: The synthesis of CuS/TiO2 heterostructured nanocomposites with varied TiO2 contents via simple hydrothermal and solution-based process is reported and the enhancement in the H2 evolution rate is attributed to increased light absorption and efficient charge separation with an optimum CuS coverage on TiO1.
Abstract: Photocatalytic hydrogen (H2) generation through water splitting has attracted substantial attention as a clean and renewable energy generation process that has enormous potential in converting solar-to-chemical energy using suitable photocatalysts. The major bottleneck in the development of semiconductor-based photocatalysts lies in poor light absorption and fast recombination of photogenerated electron-hole pairs. Herein we report the synthesis of CuS/TiO2 heterostructured nanocomposites with varied TiO2 contents via simple hydrothermal and solution-based process. The morphology, crystal structure, composition, and optical properties of the as-synthesized CuS/TiO2 hybrids are evaluated in detail. Controlling the CuS/TiO2 ratio to an optimum value leads to the highest photocatalytic H2 production rate of 1262 μmol h-1 g-1, which is 9.7 and 9.3 times higher than that of pristine TiO2 nanospindles and CuS nanoflakes under irradiation, respectively. The enhancement in the H2 evolution rate is attributed to increased light absorption and efficient charge separation with an optimum CuS coverage on TiO2. The photoluminescence and photoelectrochemical measurements further confirm the efficient separation of charge carriers in the CuS/TiO2 hybrid. The mechanism and synergistic role of CuS and TiO2 semiconductors for enhanced photoactivity is further delineated.
143 citations
TL;DR: A series of 12-connected lanthanide cluster based metal-organic frameworks (MOFs) constructed by [Ln6(μ3-OH)8(COO-)12] secondary building units (SBUs) and 2-aminobenzenedicarboxylate (BDC-NH2) ligands exhibit high chemical stability and generic thermal stability, especially in acidic and basic conditions.
Abstract: A series of 12-connected lanthanide cluster based metal–organic frameworks (MOFs) have been constructed by [Ln6(μ3-OH)8(COO−)12] secondary building units (SBUs) and 2-aminobenzenedicarboxylate (BDC-NH2) ligands. These obtained materials exhibit high chemical stability and generic thermal stability, especially in acidic and basic conditions. They also present commendable CO2 adsorption capacity, and Yb-BDC-NH2 was further confirmed by a breakthrough experiment under both dry and wet conditions. Moreover, these materials possess both Lewis acid and Bronsted base sites that can catalyze one-pot tandem deacetalization–Knoevenagel condensation reactions.
140 citations
TL;DR: The maximum sensor sensitivity of Y2MgTiO6:Mn4+ is determined to be as high as 0.001 42 K-1 at 153 K, which demonstrates potential applications for the optical thermometry at low-temperature environments.
Abstract: Mn4+-doped Y2MgTiO6 phosphors are synthesized by the traditional solid-state method. Powder X-ray diffraction, scanning electron microscope, and energy-dispersive X-ray spectrometer are employed to...
138 citations
TL;DR: It was found that the structural features and CO2 affinity properties of these MTV-MOFs can be tuned by introducing imidazolium groups or doping zinc sites, and ZnTCPP⊂(Br-)Etim-UiO-66 exhibited enhanced catalytic activities compared to other MTV- MOFs herein for obtaining the 3-allyloxy-1,2-proplyene carbonate product.
Abstract: The design and synthesis of metal–organic frameworks (MOFs) enclosed with multiple catalytic active sites is favorable for cooperative catalysis, but is is still challenging. Herein, we developed a sequential postsynthetic ionization and metalation strategy to prepare bifunctional multivariate Zr-MOFs incorporating zinc porphyrin and imidazolium functionalities. Using this facile strategy, tetratopic [5,10,15,20-tetrakis(4-carboxyphenyl)porphyrinato]zinc(II) (ZnTCPP) ligands were successfully installed into the cationic Zr-MOF to obtain ZnTCPP⊂(Br–)Etim-UiO-66. These MTV-MOFs, including TCPP⊂Im-UiO-66, TCPP⊂(Br–)Etim-UiO-66, and ZnTCPP⊂(Br–)Etim-UiO-66, were well characterized and used in CO2 capture and conversion into cyclic carbonate from allyl glycidyl ether and CO2 under cocatalyst-free and 1 bar CO2 pressure conditions. It was found that the structural features and CO2 affinity properties of these MTV-MOFs can be tuned by introducing imidazolium groups or doping zinc sites. Additionally, ZnTCPP⊂(Br–...
TL;DR: The excellent luminescent performance of K2MgGeO4:0.01Bi3+ suggests that it is a promising orange-emitting phosphor for near-ultraviolet WLEDs, which contains abundant red light component in its emission spectrum.
Abstract: In this article we synthesized a series of phosphors K2MgGeO4:Bi3+ with high brightness for white light-emitting diodes (WLEDs) conversion and investigated their crystal structures and luminescence properties using powder X-ray diffraction, diffuse reflectance spectra, X-ray photoelectron spectroscopy, photoluminescence spectra, and absolute quantum efficiency K2MgGeO4:Bi3+ phosphor exhibits intense absorption in near-UV area and presents a broad asymmetric emission band with the main peak located at 614 nm, which was ascribed to the 3P1 → 1S0 transition of Bi3+ The absolute quantum efficiency of the K2MgGeO4:001Bi3+ phosphor was measured to be 666% Also, this orange emission with color chromaticity coordinates of (04989, 04400) has an excellent resistance to thermal quenching: its integrated intensity at 393 K still maintained ∼85% of the one at room temperature The WLEDs devices with Ra = 938 were fabricated by employing K2MgGeO4:001Bi3+ as an orange phosphor, which contains abundant red light
TL;DR: This work designed and synthesized a new amino-decorated bridging ligand H2APDA and employed it to react with the environmentally friendly Mg(II) ions to construct a novel magnesium luminescent metal-organic framework (Mg-LMOF), namely [Mg2(APDA)2( H2O)3]·5DMA·5H2O (M g-APDA).
Abstract: Iron(III) ions play a vital role in living biological systems, while organic pollutants including pesticides and antibiotics pose a great threat to the ecological environment. Effective detection for these species is crucial for human health and environmental protection. In this work, we designed and synthesized a new amino-decorated bridging ligand H2APDA and employed it to react with the environmentally friendly Mg(II) ions to construct a novel magnesium luminescent metal-organic framework (Mg-LMOF), namely [Mg2(APDA)2(H2O)3]·5DMA·5H2O (Mg-APDA). The as-synthesized Mg-LMOF is a three-dimensional framework with one-dimensional hexagonal channels. These microporous channels are decorated with Lewis-base amino sites and uncoordinated O atoms, which facilitate the Mg-APDA to anchor and recognize various analytes. Mg-APDA can be used as a multiresponsive luminescent sensor to detect Fe(III) ions, pesticides, and antibiotics effectively. To the best of our knowledge, this work represents the first amino-decorated Mg-LMOF as an efficient fluorescent sensor for detecting metal ions, pesticides, and antibiotics simultaneously.
TL;DR: Molecular orbital and adaptive natural density partitioning analyses indicate that the enhanced stability of half-sandwich TaB12- is due to the strong interaction of the Ta atom with surrounding B atoms and σ B-B bonds in the B12 moiety.
Abstract: Transition-metal (TM)-doped boron clusters have received considerable attention in recent years, in part, because of their remarkable size-dependent structural and electronic properties. However, the structures of medium-sized boron clusters doped with TM atoms are still not well-known because of the much increased complexity of the potential surface as well as the rapid increase in the number of low-energy isomers, which are the challenges in cluster structural searches. Here, by means of an unbiased structure search, we systematically investigated the structural evolution of medium-sized tantalum-doped boron clusters, TaBn0/- (n = 10-20). The results revealed that TaBn0/- (n = 10-15) clusters adopt half-sandwich molecular geometries, with the notable exception of TaB10-, while for n = 16-18 and 19-20, the lowest-energy clusters are characterized by drum-type geometries and tubular molecules with two B atoms on the top, respectively. Good agreement between the calculated and experimental photoelectron spectra strongly support the validity of our global minimum structures. Molecular orbital and adaptive natural density partitioning analyses indicate that the enhanced stability of half-sandwich TaB12- is due to the strong interaction of the Ta atom (5d orbitals) with surrounding B atoms (2p orbitals) and σ B-B bonds in the B12 moiety.
TL;DR: This work presented several strategies for optical temperature sensing based on UC spectra of the Y2WO6:Yb3+-Er3+/Ho3++/Tm3+ phosphors by using a fluorescence intensity ratio technique.
Abstract: Upconversion (UC) based luminescent materials have promising applications in noncontact temperature sensors. How to improve the sensitivity is one main object at present. This work presented several strategies for optical temperature sensing based on UC spectra of the Y2WO6:Yb3+-Er3+/Ho3+/Tm3+ phosphors. The improvement for the relative ( SR) and absolute ( SA) sensitivities were discussed by using a fluorescence intensity ratio technique. It includes thermally coupled levels (TCLs) and non-TCLs. It was proposed that a piecewise expression could be employed to achieve high SA value for TCLs. However, improving the SR value is limited for TCLs. With regard to the non-TCLs, SR and SA are not restricted, but not easy to be improved synchronously. On the other hand, the morphology and UC spectra of the samples were also studied. The above investigation could be instructive to develop new luminescent materials with high sensitivity.
TL;DR: The temperature-dependent structure evolution of the hybrid halide perovskite compounds, FASnI3 and FAPbBr3, has been monitored using high-resolution synchrotron X-ray powder diffraction to suggest dynamic motion is occurring in the inorganic sublattice due to the flexibility of the in organic network and dynamic lone pair stereochemical activity on the B-site.
Abstract: The temperature-dependent structure evolution of the hybrid halide perovskite compounds, formamidinium tin iodide (FASnI3, FA+ = CH[NH2]2+) and formamidinium lead bromide (FAPbBr3), has been monitored using high-resolution synchrotron X-ray powder diffraction between 300 and 100 K. The data are consistent with a transition from cubic Pm3m (No. 221) to tetragonal P4/mbm (No. 127) for both materials upon cooling; this occurs for FAPbBr3 between 275 and 250 K, and for FASnI3 between 250 and 225 K. Upon further cooling, between 150 and 125 K, both materials undergo a transition to an orthorhombic Pnma (No. 62) structure. The transitions are confirmed by calorimetry and dielectric measurements. In the tetragonal regime, the coefficients of volumetric thermal expansion of FASnI3 and FAPbBr3 are among the highest recorded for any extended inorganic crystalline solid, reaching 219 ppm K–1 for FASnI3 at 225 K. Atomic displacement parameters of all atoms for both materials suggest dynamic motion is occurring in the...
TL;DR: Data indicate that the phototoxic response may result from the release of both CO and the rhenium-containing photoproduct, as well as the production of 1O2.
Abstract: Fifteen water-soluble rhenium compounds of the general formula [Re(CO)3(NN)(PR3)]+, where NN is a diimine ligand and PR3 is 1,3,5-triaza-7-phosphaadamantane (PTA), tris(hydroxymethyl)phosphine (THP), or 1,4-diacetyl-1,3,7-triaza-5-phosphabicylco[3.3.1]nonane (DAPTA), were synthesized and characterized by multinuclear NMR spectroscopy, IR spectroscopy, and X-ray crystallography. The complexes bearing the THP and DAPTA ligands exhibit triplet-based luminescence in air-equilibrated aqueous solutions with quantum yields ranging from 3.4 to 11.5%. Furthermore, the THP and DAPTA complexes undergo photosubstitution of a CO ligand upon irradiation with 365 nm light with quantum yields ranging from 1.1 to 5.5% and sensitize the formation of 1O2 with quantum yields as high as 70%. In contrast, all of the complexes bearing the PTA ligand are nonemissive and do not undergo photosubstitution upon irradiation with 365 nm light. These compounds were evaluated as photoactivated anticancer agents in human cervical (HeLa),...
TL;DR: UiO-66@Butyne has been found to be selective for Hg(II) ions even in the presence of other metal ions, and renders the sensitive detection of Hg2+ ion in an aqueous phase.
Abstract: A metal–organic framework (MOF)-based highly selective and sensitive probe (UiO-66@Butyne) for the detection of Hg(II) ion has been developed. To the best our knowledge, this is the foremost example of a chemodosimeter-based approach to sense Hg(II) ion using a MOF-based probe. The chemical stability of UiO-66@Butyne renders the sensitive detection of Hg2+ ion in an aqueous phase. UiO-66@Butyne has been found to be selective for Hg(II) ions even in the presence of other metal ions.
TL;DR: It is shown that CaB5O7F3 is a promising DUV NLO material and exhibits excellent NLO performances including large band gap, large second harmonic generation intensity, and moderate birefringence that enables frequency doubling down to 183 nm.
Abstract: Noncentrosymmetric (NCS) fluorooxoborates are one of the most attractive systems for discovering the new deep-ultraviolet (DUV) nonlinear optical (NLO) materials. Here, we report the formation, crystal structure, and optical properties of a new NCS alkaline earth fluorooxoborate: CaB5O7F3. It exhibits excellent NLO performances including large band gap (8.75 eV), large second harmonic generation intensity (2 × KH2PO4 and 0.4 × β-BaB2O4, under 1064 and 532 nm radiation, respectively), and moderate birefringence (0.07 @ 1064 nm) that enables frequency doubling down to 183 nm. It demonstrates that CaB5O7F3 is a promising DUV NLO material.
TL;DR: The w-LEDs component constructed by coupling the UV-LED chip with red/green/blue phosphors demonstrate an excellent correlated color temperature (CCT) of 3404 K, as well as color rendering index (CRI) of 86.8.
Abstract: Non-rare-earth Mn4+-doped double-perovskite (Ba1–xSrx)2YSbO6:Mn4+ red-emitting phosphors with adjustable photoluminescence are fabricated via traditional high-temperature sintering reaction. The structural evolution, variation of Mn4+ local environment, luminescent properties, and thermal quenching are studied systematically. With elevation of Sr2+ substituting content, the major diffraction peak moves up to a higher angle gradually. Impressively, with increasing the substitution of Ba2+ with Sr2+ cation from 0 to 100%, the emission band shifts to short-wavelength in a systematic way resulting from the higher transition energy from excited states to ground states. Besides, this blue-shift appearance can be illuminated adequately using the crystal field strength. The thermal quenching of the obtained solid solution is dramatically affected by the composition, with the PL intensity increasing 16% at 423 K going from x = 0 to 1.0. The w-LEDs component constructed by coupling the UV-LED chip with red/green/bl...
TL;DR: PMOF 1 as unusual visible-light photocatalyst exhibit significantly enhanced photocatalytic activity under visible- light and excellent stability during the photocatalysis process for recovering and recycling, as well as photocatallytic hydrogen evolution activity.
Abstract: Two stable 3D polyoxometalate-based metal–organic frameworks (PMOFs), [CuI12(trz)8(H2O)2][α-SiW12O40]·2H2O (1) and [CuI12(trz)8Cl][α-PW12O40] (2) (Htrz = 1-H-1,2,4-triazole) based on Keggin-type POMs were successfully obtained and fully characterized. The basic building units of the two PMOFs are [CuI12(trz)8], but polyoxoanion (POA) template effect leads to different structures and properties: 1 represents an interesting example that [α-SiW12O40]4– locate in the nine-membered Cu-trz rings through Cu···O weak interactions to form a 3D framework, whereas 2 shows a 3D structure constructed from 2D bilayer cationic network [CuI12(trz)8Cl]3+ and [α-PW12O40]3– lying in the adjacent layers via Cu···O weak interactions. PMOF 1 as unusual visible-light photocatalyst exhibit significantly enhanced photocatalytic activity under visible-light and excellent stability during the photocatalysis process for recovering and recycling, as well as photocatalytic hydrogen evolution activity.
TL;DR: This Viewpoint describes major advances pertaining to perfunctionalized boron clusters in synthesis and their respective applications, and suggests potential new directions for these clusters as they apply to both synthetic methods and applications.
Abstract: This Viewpoint describes major advances pertaining to perfunctionalized boron clusters in synthesis and their respective applications. The first portion of this work highlights key synthetic methods, allowing one to access a wide range of polyhedral boranes (B4 and B6–B12 cluster cores) that contain exhaustively functionalized vertices. The second portion of this Viewpoint showcases the historical developments in using these molecules for applications ranging from materials science to medicine. Last, we suggest potential new directions for these clusters as they apply to both synthetic methods and applications.
TL;DR: The reported strategy expands the use of the TPSSh functional to other metals and oxidation states other than FeII, making it the method of choice to study SCO in first row transition metal complexes.
Abstract: A systematic study of the performance of several density functional methodologies to study spin-crossover (SCO) on first row transition metal complexes is reported. All functionals have been tested against several mononuclear systems containing first row transition metal complexes and exhibiting spin-crossover. Among the tested functionals, the hybrid meta-GGA functional TPSSh with a triple-ζ basis set including polarization functions on all atoms provides the best results across different metals and oxidation states, and its performance in both predicting the correct ground state and the right energy window for SCO to occur is quite satisfactory. The effect of some additional contributions, such as zero-point energies, relativistic effects, and intramolecular dispersion interactions, has been analyzed. The reported strategy thus expands the use of the TPSSh functional to other metals and oxidation states other than FeII, making it the method of choice to study SCO in first row transition metal complexes. Additionally, the presented results validate the potential use of the TPSSh functional for virtual screening of new molecules with SCO, or its use in the study of the electronic structure of such systems.
TL;DR: The formation of a hierarchical flower-like morphology of the photocatalyst has been established by an HRTEM and FESEM study and the efficient separation of electron-hole charge carriers at the interface is supported by a photoluminescence study and EIS measurements.
Abstract: Due to the enormous demand for effective conversion of solar energy and large-scale hydrogen production, cost-effective and long-lasting photocatalysts are believed to be necessary for global produ...
TL;DR: The luminescent composite film doped with 1% (w/w) of compound 1, 1@PMMA (PMMA = poly(methyl methacrylate)), can be successfully prepared, which endows efficient sensitivity for Fe3+ and Cr2O72- detection and thus provides great potential for future applications.
Abstract: Three iridium(III)-based metal–organic frameworks (MOFs), namely [Cd3{Ir(ppy-COO)3}2(DMF)2(H2O)4]·6H2O·2DMF (1), [Cd3{Ir(ppy-COO)3}2(DMA)2(H2O)2]·0.5H2O·2DMA (2), and [Cd3{Ir(ppy-COO)3}2(DEF)2(H2O)2]·8H2O·2DEF (3) (ppy-COOH = methyl-3-(pyridin-2-yl)benzoic acid, DMF = N,N-dimethylformamide, DMA = N,N-dimethylacetamide, DEF = N,N-diethylformamide), have been synthesized and characterized. Single-crystal structural determinations reveal that compounds 1–3 are isostructural, showing a three-dimensional framework structure with (3,6) connected rtl topologyin whose trimers of {Cd3(COO)6} are cross-linked by Ir(ppy-COO)33–. The structures are completely different from those of other Ir(III)-based MOFs. Compound 1 was selected for a detailed study on sensing properties. The excellent luminescence as well as good water stability of 1 makes it a highly selective and sensitive multiresponsive luminescent sensor for Fe3+ and Cr2O72–. The detection limits are 67.8 and 145.1 ppb, respectively. Compound 1 can also be u...
TL;DR: A new three-dimensional europium-based metal-organic framework has been synthesized with the newly designed ligand L (6-[1-(4-carboxyphenyl)-1 H-1,2,3-triazol-4-yl]nicotinic acid), which acts as a dual sensor for the phosphate anion and Fe3+ ion in aqueous media.
Abstract: A new three-dimensional europium-based metal–organic framework has been synthesized with the newly designed ligand L (6-[1-(4-carboxyphenyl)-1H-1,2,3-triazol-4-yl]nicotinic acid) This compound acts as a dual sensor for the phosphate anion and Fe3+ ion in aqueous media The mechanistic aspect of this selectivity and sensitivity was explored through several spectroscopic methods and then correlated with the corresponding structure
TL;DR: This paper built on existing literature provides a thorough development of the fertile ground of the coordination architecture for catalysis and its future direction of propagation with special emphasis on molecular barrels.
Abstract: The scholastic significance of supramolecular chemistry continues to grow with the recent development of catalytic transformations in confined space of supramolecular architectures. It has come a long way from a natural cavity containing molecules to modern smart materials capable of manipulating reaction pathways. The rise of self-assembled coordination complexes provided a diverse array of host structures. Starting from purely organic compounds to metalloligand surrogates, supramolecular host cavities were tuned according to the requirement of the reactions. The understanding of their participation in a reaction led to better usage of those assemblies for specific reaction sequences. Commencing from cyclodextrin, a wide range of organic molecules was used for cage-catalyzed organic transformations. However, difficulties in synthesis and a tedious purification procedure led chemists to choose a different pathway of metal–ligand coordination-driven self-assembly. The latter stood out as a potential replac...
TL;DR: It was found that the strong fluorescence of the nanostructures could be selectively quenched by cefixime (CFX) in aqueous solution and could be prepared as a highly sensitive fluorescence probe for selective detection of CFX in an aqueously system.
Abstract: Tb3+-doped zinc-based coordination polymer nanospindle bundles (Zn-PDC/Tb3+, or [Zn(2,5-PDC)(H2O)2]·H2O/Tb3+) were synthesized by a simple solution precipitation route at room temperature, employing Zn(NO3)2, Tb(NO3)3, and 2,5-Na2PDC as the initial reactants, and a mixture of water and ethanol with the volume ratio of 10:10 as the solvent. The as-obtained nanostructures presented strong fluorescent emission under the excitation of 298 nm light, which was attributed to the characteristic emission of the Tb3+ ion. It was found that the above-mentioned strong fluorescence of the nanostructures could be selectively quenched by cefixime (CFX) in aqueous solution. The other common antibiotics hardly interfered. Thus, as-obtained Zn-PDC/Tb3+ nanostructures could be prepared as a highly sensitive fluorescence probe for selective detection of CFX in an aqueous system. The corresponding detection limit reached 72 ppb. The theoretic calculation and UV-vis absorption experiments confirmed that the fluorescence quenching of Zn-PDC/Tb3+ nanostructures toward CFX should be attributed to the electron transfer and the fluorescence inner filter effect between the fluorescent matter and the analyte. In addition, the strong fluorescence of the nanostructures could also be selectively quenched by acetone in the water system.
TL;DR: The cytotoxic activity of the NCPs has been studied using human colorectal carcinoma cells (HCT 116) and significant cell death is observed for NCP 2, which is likely to be due to mitochondrial-assisted apoptosis as is evident from immunofluorescence study.
Abstract: Five new coordination polymers (CPs) namely, [{Zn(μ2-H2O)0.5(5N3-IPA)(2,2'-bpe)}]∞ (1), [{Zn(μ2-H2O)0.5(5N3-IPA)(1,10-phen)}]∞ (2), [{Zn(5N3-IPA)(1,2-bpe)}]∞ (3), [{Zn(5N3-IPA)(1,2-bpey)}]∞ (4), and [{Zn(H2O)(5N3-IPA)(4,4'-tme)}(H2O)0.5]∞ (5) (5N3-H2IPA = 5-azidoisophthalic acid, 2,2'-bpe= 2,2'-bipyridine, 1,10-phen = 1,10-phenanthroline, 1,2-bpe = 1,2-bis(4-pyridyl)ethane, 1,2-bpey = 1,2-bis(4-pyridyl)ethylene, 4,4'-tme = 4,4'-trimethylenedipyridine), have been synthesized based on a mixed ligand approach adopting a solvothermal technique. Depending upon the intrinsic structural flexibility of the bis-pyridyl coligands, interesting structural topologies have also been observed in the resulting CPs: Sra SrAl2 type topology for 3 and a 3-fold interpenetrated dmp topology for 4. A green hand grinding technique has been implemented to reduce the particle size of the CPs to generate nanoscale CPs (NCPs). SEM studies of NCPs reveal the formation of square and spherical particles for NCP 1 and 2, respectively, and nano rod for NCP 3, 4, and 5. Remarkably, when scaled down to nano range all the NCPs retain their crystalline nature. The cytotoxic activity of the NCPs (1-5) has been studied using human colorectal carcinoma cells (HCT 116). Significant cell death is observed for NCP 2, which is further corroborated by cell growth inhibition study. The observed cell death is likely to be due to mitochondrial-assisted apoptosis as is evident from immunofluorescence study.
TL;DR: HEAs have potential as hydrogen storage materials because of favorable absorption in all interstitial sites within the structure, and the large lattice strain in the HEA seems favorable for absorption in both octahedral and tetrahedral sites.
Abstract: A high-entropy alloy (HEA) of HfNbTiVZr was synthesized using an arc furnace followed by ball milling The hydrogen absorption mechanism was studied by in situ X-ray diffraction at different temperatures and by in situ and ex situ neutron diffraction experiments The body centered cubic (BCC) metal phase undergoes a phase transformation to a body centered tetragonal (BCT) hydride phase with hydrogen occupying both tetrahedral and octahedral interstitial sites in the structure Hydrogen cycling of the alloy at 500 °C is stable The large lattice strain in the HEA seems favorable for absorption in both octahedral and tetrahedral sites HEAs therefore have potential as hydrogen storage materials because of favorable absorption in all interstitial sites within the structure