As a hot topic of global concern, the distinguishing and detecting of antibiotic pollution is crucial owing to its adverse effect on ecosystems and human health stemming from excessive use and poor ...management. Herein, a water‐stable lanthanide coordination polymer sensor (Dy‐TCPB) with multiple emitting centers is prepared. The versatile Dy‐TCPB can conveniently differentiate various antibiotics, and displays a self‐calibration luminescent response to nitrofurazone (NFZ) and furazolidone (FZD). Each antibiotic exhibits notable correlation to a unique combination of the two ligand‐to‐Dy ion emission intensity ratios, enabling two‐dimensional fingerprint recognition. Furthermore, the novel self‐calibration sensor demonstrates effective recognition of NFZ and FZD with excellent sensitivity and selectivity, and detection limits as low as 0.0476 and 0.0482 μm for NFZ and FZD, respectively. The synthetic approach for the fabrication of a singular coordination polymer exhibiting multiple emissions provides a promising strategy for the development of facile and effective ratiometric sensors.
Antibiotics detection: A water‐stable coordination polymer (Dy‐TCPB) with multiple emitting centers is applied to distinguish different antibiotics and for ratiometric sensing of nitrofurazone (NFZ) and furazolidone (FZD) with high sensitivity and selectivity. The polymer also shows great recycling ability, so both the synthetic and sensing strategies present a promising approach for the development of low‐cost and effective ratiometric sensors (see scheme).
The extensive implementation of hydrogen-powered technology today is limited by a number of fundamental problems related to materials research. Fuel-cell hydrogen conversion technology requires ...proton-conducting materials with high conductivity at intermediate temperatures up to 120 °C. The development of such materials remains challenging because the proton transport of many promising candidates is based on extended microstructures of water molecules, which deteriorate at temperatures above the boiling point. Here we show the impregnation of the mesoporous metal–organic framework (MOF) MIL-101 by nonvolatile acids H2SO4 and H3PO4. Such a simple approach affords solid materials with potent proton-conducting properties at moderate temperatures, which is critically important for the proper function of on-board automobile fuel cells. The proton conductivities of the H2SO4@MIL-101 and H3PO4@MIL-101 at T = 150 °C and low humidity outperform those of any other MOF-based materials and could be compared with the best proton conductors, such as Nafion.
Solvothermal reaction of 5,5′‐(pyridine‐2,6‐diylbis(oxy))diisophthalic acid (H4L) with europium(III) or terbium(III) nitrates in acetonitrile‐water (1 : 1) at 120 °C gave rise to isostructural 2D ...coordination polymers, Ln(HL)(H2O)3∞ (NIIC‐1‐Eu and NIIC‐1‐Tb), the layers of which are composed by eight‐coordinated lanthanide(III) ions interconnected by triply deprotonated ligands HL3−. The layers are packed in the crystal without any specific intermolecular interactions between them, allowing the facile preparation of stable water suspensions, in which NIIC‐1‐Tb exhibited top‐performing sensing properties through luminescence quenching effect with exceptionally low detection limits towards Fe3+ (LOD 8.62 nM), ofloxacin (OFX) antibiotic (LOD 3.91 nM) and cotton phytotoxicant gossypol (LOD 2.27 nM). In addition to low detection limit and high selectivity, NIIC‐1‐Tb features fast sensing response (within 60–90 seconds), making it superior to other MOF‐based sensors for metal cations and organic toxicants. The photoluminescence quantum yield of NIIC‐1‐Tb was 93 %, one of the highest among lanthanide MOFs. Mixed‐metal coordination polymers NIIC‐1‐EuxTb1−x demonstrated efficient photoluminescence, the color of which could be modulated by the excitation wavelength and time delay for emission monitoring (within 1 millisecond). Furthermore, an original 2D QR‐coding scheme was designed for anti‐counterfeiting labeling of goods based on unique and tunable emission spectra of NIIC‐1‐Ln coordination polymers.
A highly emissive terbium(III) MOF exhibits excellent sensing properties with exceptionally low detection limits towards iron(III), ofloxacin and gossypol in water. A novel anti‐counterfeiting QR‐coding Scheme based on unique and tunable emission spectra of Ln‐MOFs was designed.
The metal–organic framework Cr-MIL-101 was found to be active in the solvent-free coupling of CO2 and epoxides to produce cyclic carbonates at both high-pressure (100atm CO2) and low-pressure (8atm ...CO2) conditions in the temperature range of 25–120°C. Display omitted
► Cr-MIL-101 is an effective catalyst for the synthesis of cyclic carbonates. ► The presence of TBABr co-catalyst is required at room temperature. ► The possibility of the catalyst recovery and recycling was explored.
The catalytic performance of the metal–organic framework Cr-MIL-101 in solvent-free coupling of CO2 and epoxides to produce cyclic carbonates has been explored at both high-pressure (100atm CO2) and low-pressure (8atm CO2) conditions in the temperature range of 25–120°C. The presence of tetrabutylammonium bromide as co-catalyst was found to be crucial for the formation of the cyclic carbonates at mild reaction conditions (8atm CO2, 25°C). The yield of the styrene carbonate attained 95% at 98% substrate conversion after 48h. Cycloaddition of CO2 to propylene oxide gave propylene carbonate with 82% yield at 91% conversion after 24h. Heterogeneous nature of catalysis was proved by hot catalyst filtration test, indicating no leaching of active chromium species. However, a deterioration of the catalytic properties occurred after catalyst recycling due to pores blockage with the reaction products and gradual degradation of the MIL-101 structure.
•Metal-organic frameworks MIL-100 and 101 catalyze solvent-free alkene oxidation.•The product selectivity strongly depends on the nature of metal (Fe or Cr).•Catalyst stability reduces in the order ...Cr-MIL-101(100)•Fe-MIL-100 Fe-MIL-101.•MIL-100 and 101 catalyze oxidation of anthracene with tert-butyl hydroperoxide.•Quantitative anthraquinone yield is attained over Cr-MIL-101.
Catalytic properties of Fe- and Cr-based metal-organic frameworks (MOFs) MIL-100 and MIL-101 have been assessed in two liquid-phase reactions: solvent-free allylic oxidation of alkenes (cyclohexene, α- and β-pinenes) with molecular oxygen and oxidation of anthracene (AN) with tert-butyl hydroperoxide (TBHP). In the oxidation of alkenes, the product selectivity strongly depends on the nature of metal (Fe or Cr) but, for the same metal, only slightly differs for the MIL-100 and MIL-101 structures. The Fe-containing MOFs afford the formation of unsaturated alcohols while Cr-based MOFs give mainly unsaturated ketones. Both Cr-MIL-100 and Cr-MIL-101 favor decomposition of cyclohexenyl hydroperoxide to produce 2-cyclohexen-1-one with 67–69% selectivity. Stability toward destruction reduced in the order Cr-MIL-101, Cr-MIL-100>Fe-MIL-100>Fe-MIL-101. In the oxidation of anthracene over both Cr-MOFs and Fe-MIL-101, the selectivity toward 9,10-anthraquinone (AQ) attained 100% at 92–100% AN conversion. The turnover frequency (TOF) decreased in the order Cr-MIL-101>Fe-MIL-101>Cr-MIL-100>Fe-MIL-100. Cr-MIL-101 revealed superior catalytic performance in terms of AN conversion, AQ selectivity and TOF. Nearly quantitative yield of AQ was obtained after 1.5h at 100°C in chlorobenzene as solvent. No leaching of active metal occurred under optimal reaction conditions and the MOFs could be recycled several times without deterioration of the catalytic properties.
The first example of a triply bridging (μ3‐P) phosphine ligand has been discovered in the crown‐shaped Cu3(μ2‐Hal)3L (Hal=Cl, Br, or I) complexes supported by tris2‐(2‐pyridyl)ethylphosphine (L). ...Theoretical analysis completely confirms the observed μ3‐P‐bridging pattern, revealing the interaction of the same lone pair of phosphorus with three valence 4s‐orbitals of Cu atoms. The presented complexes exhibit outstanding blue phosphorescence (λem=442–465 nm) with the quantum efficiency reaching 100 %. The complex Cu3(μ2‐I)3L also exhibits remarkable thermo‐ and mechanochromic luminescence resulting in a sharp change in the emission colour upon external stimuli. These findings essentially contribute to coordination chemistry of the pnictine ligands.
Phosphines are notorious in acting exclusively as terminal donors, binding a single metal center. We have discovered that a non‐traditional scenario is possible where the phosphorus(III) atom of a R3P ligand bridges three metal atoms at once. Such triply bridging pattern is first observed in the Cu3(μ2‐Hal)3L (Hal=Cl, Br, or I) complexes, which also exhibit remarkable luminescence properties.
Separation of hydrocarbon molecules, such as benzene/cyclohexane and o-xylene/m-xylene/p-xylene, is relevant due to their widespread application as chemical feedstock but challenging because of their ...similar boiling points and close molecular sizes. Physisorption separation could offer an energy-efficient solution to this problem, but the design and synthesis of sorbents that exhibit high selectivity for one of the hydrocarbons remain a largely unmet challenge. Herein, we report a new heterometallic MOF with a unique tortuous shape of channels decorated with aromatic sorption sites Li2Zn2(bpy)(ndc)3 (NIIC-30(Ph), bpy = 4,4′-bipyridine, ndc2– = naphthalene-1,4-dicarboxylate) and study of its benzene/cyclohexane and xylene vapor and liquid separation. For an equimolar benzene/cyclohexane mixture, it is possible to achieve a 10-fold excess of benzene in the adsorbed phase. In the case of xylenes, microporous framework NIIC-30(Ph) demonstrates outstanding selective sorption properties and becomes a new benchmark for m-/o-xylene separation. In addition, NIIC-30(Ph) is stable enough to carry out at least three separation cycles of benzene/cyclohexane mixtures or ternary o-xylene/m-xylene/p-xylene mixtures both in the liquid and in the vapor phase. Insights into the performance of NIIC-30(Ph) are gained from X-ray structural studies of each aromatic guest inclusion compound.
In the presence of different cations, reactions of SbBr63− and I2 result in a new family of diverse supramolecular 1D polyiodide‐bromoantimonate networks. The coordination number of Sb, as well as ...geometry of assembling {Ix}n− polyhalide units, can vary, resulting in unprecedented structural types. The nature of I⋅⋅⋅Br interactions was studied by DFT calculations; estimated energy values are 1.6–6.9 kcal mol−1. Some of the compounds showed strong photoconductivity in thin films, suggesting multiple feasible applications in optoelectronics and solar energy conversion.
Photoconductive metal‐polyhalide hybrids: In the presence of different cations, reactions of SbBr63− and I2 result in a family of polyiodide‐bromoantimonate networks. The coordination number of Sb, as well as geometry of assembling {BrxIy}n− polyhalide units, varies, resulting in unprecedented structural types. Some of the compounds showed strong photoconductivity in thin films, suggesting multiple feasible applications in optoelectronics and solar energy conversion.
The conversion of metal–organic frameworks (MOFs) into derivatives with a well‐defined shape and composition is considered a reliable way to produce efficient catalysts and energy capacitors at the ...nanometer scale. Yet, approaches based on conventional melting of MOFs provide the derivatives such as amorphous carbon, metal oxides, or metallic nanoclusters with an appropriate morphology. Here ultrafast melting of MOFs is utilized by femtosecond laser pulses to produce a new generation of derivatives with complex morphology and enhanced nonlinear optical response. It is revealed that such a nonequilibrium process allows conversion of interpenetrated 3D MOFs comprising flexible ligands into well‐organized spheres with a metal oxide dendrite core and amorphous organic shell. The ability to produce such derivatives with a complex morphology is directly dependent on the electronic structure, crystal density, ligand flexibility, and morphology of initial MOFs. An enhanced second harmonic generation and three‐photon luminescence are also demonstrated due to the resonant interaction of 100–1000 nm spherical derivatives with light. The results obtained are in the favor of new approaches for melting special types of MOFs for nonlinear nanophotonics.
Ultrafast melting of 3D metal–organic frameworks comprising flexible ligands by femtosecond laser pulses allows producing a new kind of derivative as well‐organized spheres with a metal oxide dendrite core and an amorphous organic shell, which are suitable for nonlinear nanophotonics due to enhanced second harmonic generation and three‐photon luminescence.
Five new metal-organic frameworks based on Mn(II) and 2,2'-bithiophen-5,5'-dicarboxylate (btdc
) with various chelating N-donor ligands (2,2'-bipyridyl = bpy; 5,5'-dimethyl-2,2'-bipyridyl = ...5,5'-dmbpy; 4,4'-dimethyl-2,2'-bipyridyl = 4,4'-dmbpy) Mn
(btdc)
(bpy)
·4DMF,
; Mn
(btdc)
(5,5'-dmbpy)
·5DMF,
; Mn(btdc)(4,4;-dmbpy),
; Mn
(btdc)
(bpy)(dmf)·0.5DMF,
; Mn
(btdc)
(5,5'-dmbpy)(dmf)·DMF,
(dmf, DMF = N,N-dimethylformamide) have been synthesized, and their crystal structure has been established using single-crystal X-ray diffraction analysis (XRD). The chemical and phase purities of Compounds
-
have been confirmed via powder X-ray diffraction, thermogravimetric, and chemical analyses as well as IR spectroscopy. The influence of the bulkiness of the chelating N-donor ligand on the dimensionality and structure of the coordination polymer has been analyzed, and the decrease in the framework dimensionality, as well as the secondary building unit's nuclearity and connectivity, has been observed for bulkier ligands. For three-dimensional (3D) coordination polymer
, the textural and gas adsorption properties have been studied, revealing noticeable ideal adsorbed solution theory (IAST) CO
/N
and CO
/CO selectivity factors (31.0 at 273 K and 19.1 at 298 K and 25.7 at 273 K and 17.0 at 298 K, respectively, for the equimolar composition and the total pressure of 1 bar). Moreover, significant adsorption selectivity for binary C
-C
hydrocarbons mixtures (33.4 and 24.9 for C
H
/CH
, 24.8 and 17.7 for C
H
/CH
, 29.3 and 19.1 for C
H
/CH
at 273 K and 298 K, respectively, for the equimolar composition and the total pressure of 1 bar) has been observed, making it possible to separate on
natural, shale, and associated petroleum gas into valuable individual components. The ability of Compound
to separate benzene and cyclohexane in a vapor phase has also been analyzed based on the adsorption isotherms of individual components measured at 298 K. The preferable adsorption of C
H
over C
H
by
at high vapor pressures (
/
= 1.36) can be explained by the existence of multiple van der Waals interactions between guest benzene molecules and the metal-organic host revealed by the XRD analysis of
immersed in pure benzene for several days (
). Interestingly, at low vapor pressures, an inversed behavior of
with preferable adsorption of C
H
over C
H
(
/
= 6.33) was observed; this is a very rare phenomenon. Moreover, magnetic properties (the temperature-dependent molar magnetic susceptibility, χ
(
) and effective magnetic moments, μ
(
), as well as the field-dependent magnetization,
(
)) have been studied for Compounds
-
, revealing paramagnetic behavior consistent with their crystal structure.
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