A stable cationic metal-organic framework (MOF) based on a neutral multidentate N-ligand and Ni(
ii
) metal center has been successfully synthesized. The cationic MOF can effectively capture anions ...(MnO
4
−
and CrO
4
2−
) from water through an anion exchange strategy. It is noteworthy that the post-synthesized cationic MOFs present better electrocatalytic performances for the hydrogen evolution reaction (HER) compared with the pristine MOF.
Through an anion exchange strategy, the post-synthetic cationic metal-organic frameworks present better electrocatalytic performances during the hydrogen evolution reaction process than the pristine one.
Salicylic acid (SA) was first bonded onto the side chains of polystyrene (PS), obtaining functional macromolecule SAPS. Using the salicylic acid-containing polystyrene as a macromolecular ligand, a ...polymer–rare earth complex, SAPS–Eu(III), was prepared. The structure of SAPS–Eu(III) was characterized, and the fluorescence properties of SAPS–Eu(III) were mainly investigated. The experimental results show that the complex SAPS–Eu(III) has fine chemical stability because of the bidentate chelating effect of salicylic acid ligand. More important, the ligand SA on the side chains of PS can strongly sensitize the fluorescence emission of the center ion, Eu3+ ion, and it enables the complex SAPS–Eu(III) to produce the apparent “Antenna Effect”. In the diluted solution of the functional macromolecule SAPS, the formed complex SAPS–Eu(III) belongs to an intramolecular complex, or an intrachain complex. For the binary intramolecular complex SAPS–Eu(III), the apparent saturated coordination number of SA of SAPS towards Eu3+ ion is equal to 10, and here the binary intrachain complex SAPS–Eu(III) has the strongest fluorescence emission. On this basis, small-molecule 1,10-phenanthroline (Phen) acting as a co-ligand is added and the ternary complex SAPS–Eu(III)–Phen will be formed. As long as a small amount of Phen is added (in the molar ratio 1:1 (n(Phen):n(Eu))), the coordination of the two kinds of ligands, SA of SAPS and Phen, to Eu3+ ion will reach complete saturation, and here the fluorescence emission of the ternary complex will be further enhanced via the complementary coordination effect in comparison with that of the binary complex SAPS–Eu(III).
► We prepared the functional polystyrene, SAPS, on whose side chain salicylic acid ligand was bonded. ► The polymer-rare earth complex, SAPS–Eu(III), was prepared and a stronger “antenna effect” was produced. ► For the intramolecular complex SAPS–Eu(III), the apparent saturated coordination number of SA ligand towards Eu3+ ion was determined to be 10. ► The complex has the strongest fluorescence emission. ► Only by adding Phen in a molar ratio of 1:1 (Phen to Eu3+ ion) the fluorescence emission of the complex will be strengthened further.
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•FeNiOOH nanosheets are grown via in-situ chemical oxidation of 3D FeNi foam (FNF).•Oxyhydroxide species can directly act as real active catalyst for water oxidation.•The FeNiOOH/FNF ...exhibits superior OER performance to commercial IrO2 catalyst.•The superb catalytic performance owes to rational composition and structure design.
The design and synthesis of efficient and affordable electrocatalysts for water oxidation are essential to advance water splitting technology, which depends on developing earth-abundant catalytic materials with rational compositions and structures. Here, we propose a facile synthesis of FeNiOOH nanosheets grown on FeNi foam (FNF) by in-situ chemical oxidation as a novel 3D electrode for oxygen evolution reaction (OER). This FeNiOOH/FNF electrode shows outstanding electrocatalytic performance in alkaline electrolyte, including high OER activity that requires a small overpotential of 252 mV to achieve a current density of 10 mA cm−2, favourable OER kinetics with a low Tafel slope of 36.8 mV dec−1, and excellent operation stability for at least 50 h. The superior OER properties are resulted from the highly active FeNi-oxyhydroxide species and advantageous nanosheet array structure. This work presents an effective strategy to rationalize self-supporting electrodes consisting of nanostructured arrays on conductive substrates, creating new opportunities to search for more advanced materials towards a sustainable energy future.
8-Hydroxyquinoline aluminum complex-attached polysulfone was prepared
via
a polymer reaction and a coordination reaction, namely 8-hydroxyquinoline aluminum functionalization of polysulfone (PSF) was ...realized. 5-chloromethyl-8-hydroxyquinoline (CHQ) was first prepared through the chloromethylation reaction between 8-hydroxyquinoline (HQ) and chloromethylation reagent 1,4-bichloromethoxy-butane (BCMB). A polymer reaction, Friedel-Crafts alkylation reaction, was carried out between PSF and CHQ in the presence of Lewis catalyst SnCl
4
, and HQ was bonded onto the side chains of PSF, obtaining the modified polysulfone HQ-PSF. Then, the coordination reaction between HQ-PSF and 8-hydroxyquinoline aluminum complex AlQ
2
, which had two HQ ligands, was conducted, and the luminescence material AlQ
3
-PSF, in whose molecular structure 8-hydroxyquinoline aluminum complex AlQ
3
is attached chemically onto the side chains of PSF, was achieved, namely, the AlQ
3
-containing PSF was successfully prepared. The chemical structures of HQ-PSF and AlQ
3
-PSF were fully characterized by FTIR,
1
H NMR and the UV/vis absorption spectrum, and the luminescence performance of AlQ
3
-PSF was initially examined. In this work, the 8-hydroxyquinoline functionalization process of PSF was mainly investigated. The effects of the key factors on the Friedel-Crafts alkylation reaction, which occurs on the side chains of PSF macromolecules, were mainly researched, and the reaction mechanism was explored. The experimental results show that the Friedel-Crafts alkylation reaction between PSF and CHQ can proceed smoothly, and the suitable reaction conditions are as follows: a temperature of 70 °C, with
N
,
N
-dimethylformamide (DMF) as solvent, and using SnCl
4
as a Lewis catalyst. The AlQ
3
-containing polysulfone, AlQ
3
-PSF, possesses the fluorescence-emission spectrum of AlQ
3
, and its luminescence performance is nearly identical with AlQ
3
under the same concentration condition of the AlQ
3
unit.
A stable Cd(II) based luminescence coordination polymer, {Cd(tib)2(NO2)2·0.5DMA·H2O}n (CdCP, tib = 1,3,5-tris(1-imidazolyl)benzene), containing the 2D {4^3}2{4^6.6^6.8^3}-kgd cationic sheet, has ...been successfully obtained and applied as an efficient and versatile chemical sensor. Fluorescence sensing experiments revealed that CdCP displays high sensitivity and selectivity for detecting inorganic Cr(VI) anions and nitrofuran/nitroimidazole antibiotics (ABXs) in aqueous solutions via luminescence quenching effects. In addition, the mechanisms of fluorescent quenching were discussed based on optical spectroscopy and quantum chemical calculation, which indicated that the quenching mechanisms involving internal filter effect (IFE) and photo-induced electron transfer (PET). This work provides a meaningful strategy for design multi-responsive cationic MOFs/CPs as chemical sensor in the detection of pollutants in water.
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•A stable 2D cationic cadmium (II) CP with throughout reticular channels was successfully designed.•CdCP act as bifunctional chemosensor in the detection of antibiotics and Cr(VI) anions in water.•The quenching mechanisms were explored from internal filter effect and photo-induced electron transfer viewpoints.
Keywords Cationic MOFs; Chromium(VI) detection; Antibiotic detection; Fluorescent sensing; Bifunctional chemosensor Highlights * A stable 2D cationic cadmium (II) CP with throughout reticular ...channels was successfully designed. * CdCP act as bifunctional chemosensor in the detection of antibiotics and Cr(VI) anions in water. * The quenching mechanisms were explored from internal filter effect and photo-induced electron transfer viewpoints. A stable Cd(II) based luminescence coordination polymer, {Cd(tib).sub.2(NO.sub.2).sub.2*0.5DMA*H.sub.2O}.sub.n (CdCP, tib = 1,3,5-tris(1-imidazolyl)benzene), containing the 2D {4^3}.sub.2{4^6.6^6.8^3}-kgd cationic sheet, has been successfully obtained and applied as an efficient and versatile chemical sensor. Fluorescence sensing experiments revealed that CdCP displays high sensitivity and selectivity for detecting inorganic Cr(VI) anions and nitrofuran/nitroimidazole antibiotics (ABXs) in aqueous solutions via luminescence quenching effects. In addition, the mechanisms of fluorescent quenching were discussed based on optical spectroscopy and quantum chemical calculation, which indicated that the quenching mechanisms involving internal filter effect (IFE) and photo-induced electron transfer (PET). This work provides a meaningful strategy for design multi-responsive cationic MOFs/CPs as chemical sensor in the detection of pollutants in water. Author Affiliation: Department of Chemistry, College of Science, North University of China, Taiyuan 030051, PR China * Corresponding author. Article History: Received 7 February 2021; Revised 2 March 2021; Accepted 3 March 2021 Byline: Bei Li, Qingjuan Lei, Feng Wang, Dongsheng Zhao, Yuxin Deng, Lulu Yang, Liming Fan limingfan@nuc.edu.cn (*), Zhengguo Zhang zhangzhengguo@nuc.edu.cn (**)
A matrine molecule surface-imprinted material was designed and prepared using an effective surface-imprinting technique developed by our group, and its molecular recognition performance and mechanism ...were investigated in depth. Monomer glycidyl methacrylate (GMA) was first graft-polymerized on the surfaces of micron-sized silica gel particles in surface-initiated graft polymerization manner, obtaining the grafted particles PGMA/SiO
2
with high grafting degree. Subsequently, the ring-opening reaction of the epoxy groups of the grafted macromolecules PGMA with 5-aminosalicylic acid (5-ASA) was carried out, resulting in the functional grafted particle SA-PGMA/SiO
2
, on whose surfaces salicylic acid as functional group was chemically bonded. By right of the mutual strong secondary bond forces, electrostatic interaction and hydrogen bonding, SA-PGMA/SiO
2
particles produced strong adsorption for matrine. Finally, with this strong adsorption, matrine molecule surface imprinting was carried out on the surfaces of SA-PGMA/SiO
2
particles with ethylene glycol diglycidyl ether as cross-linking agent, resulting in the matrine molecule surface-imprinted material MIP-SAP/SiO
2
. The binding characteristic of MIP-SAP/SiO
2
toward matrine was investigated in depth with both batch and column methods and using oxymatrine and cytisine as two contrast alkaloids. The experimental results show that MIP-SAP/SiO
2
has special recognition selectivity and excellent binding affinity for matrine. Relative to oxymatrine and cytisine, the selectivity coefficients of MIP-SAP/SiO
2
for matrine are 5.66 and 11.17, respectively.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Synopsis
Based on p-terphenyl-2,2′',5′',5′''-tetracarboxylate acid and chelating N donors, two 1D Copper(II) CPs were constructed with good electrochemical reversibility.
Pictogram
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...•Two 1D Cu(II) CPs were designed from mixed ligands strategy.•Two Cu(II) CPs are electrochemically active materials.•The auxiliary N donors have influences on the structures and the electrochemical properties.
Two copper (II) coordination polymers, namely, Cu(tptc)0.5(bpy)(H2O)n (1), Cu(H2tptc)0.5(bpz)n (2), have been assembled from the mixed ligands of p-terphenyl-2,2′',5′',5′''-tetracarboxylate acid (H4tptc) and chelating N donors of 2,2′-bipyridine (bpy) or 2-(1H-pyrazol-3-yl)pyridine (Hbpz). Structural analysis revealed that two CPs are both 1D polymeric chains, which can be further expanded into 3D supramolecular through hydrogen bonding and π∙∙∙π packing interactions. And the electrochemical studies show that both two Cu(II) CPs are electrochemically active materials with good electrochemical reversibility.
A novel method to synthesize and immobilize porphyrins as well as manganese porphyrins on crosslinked polystyrene (CPS) microspheres was designed. The chloromethyl groups of chloromethylated CPS ...microspheres (CMCPS microspheres) were first oxidized to aldehyde groups via Kornblum oxidation reaction, obtaining aldehyde group-functionalized microspheres, and then, the synchronous synthesis and immobilization of porphyrins on CPS microspheres were carried out via the Adler reaction between solid–liquid phases, obtaining three kinds of functional microspheres, on which phenyl porphyrin (PP),
p
-chlorophenyl porphyrin (CPP) and
p
-nitrophenyl porphyrin (NPP) were immobilized. Finally, three manganese porphyrin-immobilized microspheres, MnPP–CPS, MnCPP–CPS and MnNPP–CPS, were prepared, these solid catalysts were used in the catalytic hydroxylation reaction of cyclohexane with molecular oxygen as oxidant, and their catalytic performances were mainly investigated in this work. Some surprising experimental results were obtained. The prepared immobilized manganese porphyrin catalysts display amazing catalytic activity and selectivity, and cyclohexane conversion can get up to 45 % and cyclohexanol selectivity in the reaction product can be up to 90–100 %.
Pyridylporphyrin (PyP) was synchronously synthesized and immobilized on the surfaces of crosslinked polystyrene microspheres (CPS microspheres) via an Adler reaction between solid–liquid phases, ...resulting in PyP-immobilized microspheres, PyP-CPS microspheres. Then the cationic porphyrin-immobilized microspheres, MPyP-CPS microspheres (“M” represents methyl group that comes from iodomethane), was prepared via the quaternization reaction of PyP-CPS microspheres with iodomethane as reagent. In the current work, the efficiency of the above route to immobilize pyridylporphyrin PyP on CPS microspheres was first researched by a comparison method, and then the multi-functionality of the cationic porphyrin-immobilized microspheres MPyP-CPS were mainly tested and examined from many aspects. The investigation results show that: (1) the above route to immobilize pyridylporphyrin on the surfaces of CPS microspheres is highly efficient, and the immobilization amount of PyP on CPS microspheres can get up to about 0.2 mmol g−1; (2) the cationic porphyrin-immobilized microspheres MPyP-CPS are a kind of multifunctional polymeric microspheres because of their special surface structure, and they can be used to construct different host-guest systems, resulting in many applications. MPyP-CPS microspheres can used as triphase-transfer catalysis in organic synthesis, can coordinate to transition metal ion to form immobilized metalloporphyrin catalysts to be used in the green catalytic oxidations, can be used as support of heteropoly acid to prepare heterogenous heteropoly acid catalyst, and MPyP-CPS microspheres also can used as solid adsorbent in the removal of toxic chromate ion from water medium. In a word, the polymeric microspheres supporting cationic porphyrin, MPyP-CPS microspheres, will have vast application prospect in various fields because they have special surface chemical structure.
► Pyridylporphyrin (PyP) is synchronously synthesized and immobilized on polymeric microspheres. ► This route to synthesize and immobilize pyridylporphyrin (PyP) is simple and highly effective. ► The prepared cationic pyridylporphyrin immobilized microspheres are multifunctional. ► They can construct various host-guest systems and have many applications.
