ChemistrySelect
·
2023
·Vol. 8
·期 9
·e202203332
·
IF 2.1
Cunwei Qian,Ying Wang,Xian Li,Changsheng Yao
Graphical A convenient, rapid and electrochemical one-pot protocol is designed for the synthesis of pyrazolo[3,4- b ]quinolines derivatives. The reaction is carried out in an undivided cell equipped with an iron cathode and a graphite anode in the presence of sodium bromide as a supporting electrolyte. Fourteen pyrazolo[3,4- b ]quinoline derivatives are obtained under a constant current of 30 mA after 0.14 F/mol of electricity passed. A convenient, rapid and electrochemical one-pot protocol was developed successfully for the preparation of pyrazolo[3,4- b ]-quinoline derivatives. The reaction is carried out in a 25 mL three neck flask equipped with graphite electrode as anode and iron electrode as cathode (electrode area of 1 cm 2 ) with sodium bromide as supporting electrolyte at room temperature in ethanol. Fourteen pyrazolo-[3,4- b ]-quinoline derivatives were synthesized by use of various aldehyde (including aryl aldehydes and aliphatic aldehydes), dimedone and 5-amino-3-methyl-1-phenylpyrazole as substrates in good yields (76–86 %) with a constant current of 30 mA after 0.14 F/mol of electricity passed. All aimed products were characterized by IR, 1 H NMR and HRMS. Notably, the presented method features ecologically sound, simple experimental procedure and good yields.
研究领域:
有机化学
·
电化学
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Bin Chen,Hegang Shu,Yujun Guo,Yingjie Xu
In this work, the effect of the structure and substitution of azole-based anion on the CO 2 capture and viscosity ( η ) of metal chelate-based dual functional ionic liquids (DFILs) with [K(DGA) 2 ] + cation was investigated. The CO 2 absorption capacity of DFILs at 0.1 MPa and 333.2 K shows that methyl and nitro groups on the azole-based anion, such as pyrazolide ([Pyr] − ) and imidazolide ([Im] − ), attenuate their reactivity with CO 2 through the steric hindrance and electron-withdrawing effects, respectively. Furthermore, the CO 2 absorption capacity of [K(DGA) 2 ][Pyr] is larger than that of [K(DGA) 2 ][Im], which is due to the interaction of the two adjacent N atoms in the [Pyr] − anion with CO 2 , as confirmed by DFT calculations. The CO 2 absorption mechanism shows that both [Pyr] − anion and [K(DGA) 2 ] + cation of [K(DGA) 2 ][Pyr] can chemically interact with CO 2 , making its saturated uptake at 333.2 K as high as 1.47 mol CO 2 per mole IL. Moreover, CO 2 interacts preferentially with [Pyr] − , and the [K(DGA) 2 ] + –CO 2 interaction is enhanced when the CO 2 uptake is greater than 0.5 mol CO 2 per mole IL. η of pure [K(DGA) 2 ][Pyr] is lower than that of pure [K(DGA) 2 ][Im]. η of [K(DGA) 2 ][Pyr] increases with the increase of CO 2 absorption, and the rapid increase in η after CO 2 uptake greater than 0.5 is attributed to the formation of [K(DGA) 2 ] + –CO 2 interactions.
研究领域:
化学
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环境科学
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DOI
高影响因子
JOURNAL OF FLUORESCENCE
·
2017
·Vol. 27
·期 5
·1721-1727
·
IF 1.461
Wang Fanwei,Duan Hongdong,Xing Dianxiang,Yang Geng
One novel turn-on fluorescence probe founded on conjugated pyrazole Schiff base for detecting Al 3+ was invented. The UV–vis and fluorescence spectrometer were employed to explore optical properties of this probe. The results got from those experiments indicated that this fluorescence probe manifested excellent sensitivity and selectivity for Al 3+ compared with other cations examined(Ag + , Co 2+ , Mg 2+ , Cu 2+ , Ni 2+ , Pb 2+ ,and Zn 2+ ). In addition, this probe displayed a more rapid response and remained stable between pH 6 and 9 by investigating the fluorescence intensity under different response time and various pH values. Remarkably, the detection limit for Al 3+ could lower to 1.0×10 −9 M. Therefore, the probe could be potentially applied to the environment for the detection of Al 3+ , and the availability in biological range of pH that could be further studied to make this probe apply to biological systems in the future.
研究领域:
分析化学
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环境科学
·
生物医学
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DOI
PubMed
高影响因子
POLYCYCLIC AROMATIC COMPOUNDS
·
2021
·
IF 3.744
Rui Yan,Xiaoliu Huang,Xianqing Deng,Mingxia Song
In this study, 18 pyrazole derivatives coupled with pyrazoline were synthesized and screened for their anti-inflammatory and antimicrobial activities. All the target compounds were synthesized smoothly and characterized using 1H NMR, 13C NMR, and HRMS. In vitro lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α model and in vivo xylene-induced ear-edema model were used to evaluate their anti-inflammatory activity. Antimicrobial activity against several Gram-positive strains and Gram-negative strains was evaluated using a serial dilution method. Pharmacological results indicated that most of the compounds markedly inhibited the expression of TNF-α at the concentration of 20 μg/mL. Compounds 9b showed 66.4% inhibition for the LPS-induced TNF-α release, which was superior than that of the positive control drug dexamethasone (DXMS). And compounds 4a, 4b, 5a, 5b, 6b, and 9b showed comparable inhibition activity to DXMS. In xylene-induced ear-edema model, compound 4a inhibited edema by 48.71%, which was more effective than DXMS (47.18%) in inhibiting xylene-induced ear edema. Compound 4b, 5a, 5b, 6b, and 9b showed inhibition of 36.82%, 27.65%, 45.87%, 31.78%, and 43.67%, respectively. Furthermore, compounds 4a, 5a, 5b, and 9b displayed broad-spectrum antimicrobial activity against several Gram-positive and Gram-negative bacterial. These compounds, 4a, 5a, 5b, and 9b, possess both anti-inflammatory and antimicrobial activities, thus are worth further investigation to enhance their antimicrobial activities for the development of new class of dual anti-inflammatory–antimicrobial agents.
研究领域:
药理学
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药物化学
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微生物学
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DOI
高影响因子
Polymer Chemistry
·
2013
·Vol. 5
·期 2
·607-613
·
IF 5.231
Longqiang Xiao,Shaojun Cai,Qingye Liu,Liqiong Liao,Xin Guo,Yan Li,Xiangxiang Jia,Feifei Li,Lijian Liu
Polypyrazoles with molecular weights in the range of 6500–9300 g mol−1 and yields in the range of 71.4–82.5% were synthesized successfully by catalyst-free 1,3-dipolar cycloaddition of bisdiazo compounds to bisalkynes under thermal conditions and lost merely 5% of their weights at temperatures higher than 298 °C. The porous polypyrazole–copper complex with pore diameters in the range of 1–2 μm was prepared by the coordination of polypyrazole and copper sulfate (CuSO4), which is a reusable catalyst for the Huisgen 1,3-diploar cycloaddition of alkynes and organic azides to give the corresponding triazoles with yields over 90%.
研究领域:
有机化学
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材料科学
·
催化化学
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产品关联
DOI
高影响因子
Foods
·
2022
·Vol. 11
·期 5
·669
·
IF 5.561
Lei Han,Qiong Wu,Xiaomao Wu
Rosa roxburghiihas been widely planted in China. Powdery mildew is the most serious disease ofR. roxburghiicultivation. Pyraclostrobin was widely used as a novel fungicide to control powdery mildew ofR. roxburghii. To assess the safety of pyraclostrobin for use onR. roxburghiifruits, its residue rapid analysis as well as an investigation on its dissipation behaviors and terminal residues inR. roxburghiiand soil under field conditions were carried out. The QuEChERS method was simplified using LC–MS/MS detection and combined with liquid–liquid extraction purification to allow determination of pyraclostrobin levels inR. roxburghiifruits and the soil. The fortified recoveries at 0.1~5.0 mg/kg were 93.48~102.48%, with the relative standard deviation of 0.64~3.21%. The limit of detection of the analytical method was 0.16 and 0.15 µg/kg forR. roxburghiifruit and soil, respectively. The effects of different spray equipment and formulations on the persistence of pyraclostrobin inR.roxburghiiwere as follows: gaston gasoline piggyback agricultural sprayer (5.38 d) > manual agricultural backpack sprayer (3.37 d) > knapsack multi-function electric sprayer (2.91 d), suspension concentrate (SC) (6.78 d) > wettable powder (WP) (5.64 d) > water dispersible granule (WG) (4.69 d). The degradation of pyraclostrobin followed the first-order kinetics and its half-lives inR.roxburghiiand soil were 6.20~7.79 days and 3.86~5.95 days, respectively. The terminal residues of pyraclostrobin inR.roxburghiiand soil were 0.169~1.236 mg/kg and 0.105~3.153 mg/kg, respectively. This study provides data for the establishment of the maximum residue limit (MRL) as well as the safe and rational use of pyraclostrobin inR.roxburghiiproduction.Keywords:pyraclostrobin;Rosa roxburghii;soil;dissipation;residue
研究领域:
植物保护
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环境科学
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DOI
PubMed
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
·
2023
·Vol. 52
·期 9
·1033-1047
·
IF 1.2
Li Ke,Li Renjiang,Duan Xiuzhi,Deng Dongshun
Emission of NH 3 or CO 2 containing tail gases will aggravate environmental problems of global climate warming, fog, and haze. Developing efficient absorbent for them is highly desirable. In present work, new type V pyrazole (Py)/glycerol (Gly) DESs with Py/Gly molar ratios of 1:1 and 1:2 were prepared. Their densities and viscosities with temperature were measured. The solubilities of NH 3 or CO 2 in two DESs were determined, with the near atmospheric solubilities of NH 3 and CO 2 up to 8.7052 mol·kg −1 and 0.0395 mol·kg −1 for Py/Gly DESs (1:1), respectively. Henry’s constant and the dissolution Gibbs free energy, enthalpy, and entropy changes of gas dissolution were obtained by correlating the experimental data. What’s more, Py/Gly DESs (1:1) presents potential ability to preferentially separate NH 3 from the tail gas containing NH 3 and CO 2 due to its ideal selectivity of NH 3 /CO 2 as high as 189.
研究领域:
化学工程
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环境科学
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DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 18
·6129-6137
·
IF 4
Peipei Wang,Jin Tong,Cong Meng,Qing Yuan,Wei Deng,Shu-Yan Yu,Hong-Wei Ma
Owing to their structural designability and tuneable properties, supramolecular metal–organic complexes have recently emerged as promising candidates for the sensing and detection of molecules and anions. Herein, we synthesised three tripyrazolate-linked [M6L2] metallocages with the formulas [(bpyPd)6L2](NO3)6 (1), [(dmbpyPd)6L2](NO3)6 (2), and [(phenPd)6L2](NO3)6 (3) (H3L = tris(4-(5-(trifluoromethyl)-1H-pyrazol-3-yl)phenyl)amine, bpy = 2,2′-bipyridine, dmbpy = 4,4′-dimethylbipyridine, phen = 1,10-phenanthroline). Crystallography revealed that metal-directed coordination and the bidentate chelate behaviour of the ligand induced the self-assembly of supramolecular metal–organic cages. Notably, these cages were employed as turn-on fluorescence sensors for SO2 and its derivative (HSO3−) through a disassembly mechanism. Cages 1, 2, and 3 showed a highly selective and sensitive detection of HSO3− over other common anions in aqueous solutions and of SO2 gas over other common gasses, with an excellent anti-interference ability. These metallocages were subsequently applied as sensors in environmental and biological samples. This study not only enriches the ongoing research on metal–organic supramolecular materials but also facilitates the future preparation of stimuli-responsive supramolecular coordination complexes.
研究领域:
超分子化学
·
分析化学
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DOI
PubMed
高影响因子
CHEMICAL PHYSICS LETTERS
·
2024
·
IF 2.8
Ting-ting Yan,Yi-fei Xu,Dong-yang Xi,Zhiqing Yu,Long Ma,Dan-dan Zhang,Ran Jiang
The study investigated the behavior of N-nitropyrazole (1-NP, C 3 H 3 N 3 O 2 ) under high pressure using a diamond anvil cell, Raman spectroscopy, and simulation calculations. The pressure–volume relationship of the sample, molecular interactions, and changes in optical Raman were analyzed. The Raman experiments revealed abnormal vibration intensities and a discontinuity in peak position at 2.2 GPa. For instance, the C-H stretching vibration produces a new vibration peak under pressure, and the NO 2 torsion mode continues to red shift beyond 2.2 GPa. These observations suggest that the crystal’s phase transition results from the distortion of its hydrogen-bonded network structure. The pressure relief experiment confirms the reversibility of the phase transition.
研究领域:
化学
·
材料科学
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DOI
高影响因子
RADIATION PHYSICS AND CHEMISTRY
·
2025
·
IF 3.3
Jinfeng Li,Nan Zhang,Qianwen Wang,Jianwei Zhang,Bo Tian,Zhigang Li,Haifeng Gu,Hongtao Zhao
The research for highly removal of uranium from nuclear waste is of significance for radionuclide remediation and environment. Herein, a robust pyrazolate-based metal-organic framework (NiBTP) is prepared by γ-irradiation through complexation between 1,3,5-tris(1H-pyrazol-4-yl) benzene (H 3 BTP) and Nickel (II) and presents efficient U(VI) adsorption performance. The synthesized NiBTP is characterized by XRD, FTIR, SEM, TEM, XPS and N 2 adsorption–desorption isotherm analysis. Structural characterizations demonstrate that NiBTP prepared by γ-irradiation possesses decreased BET surface area with hierarchical pore structure, but also has excellent crystallinity and high chemical stability. Batch experiments reveal that NiBTP adsorbent displays high adsorption capacity of uranium and excellent selectivity for UO 2 2+ ion in the presence of competing K + , Cs + , Sr + , Co 2+ , Mg 2+ , Ca 2+ , La 3+ and Eu 3+ ions. Thermodynamic investigation shows the adsorption process is endothermic and spontaneous. In addition, the adsorption mechanism of UO 2 2+ ion onto NiBTP is attributed to the hierarchical pore architecture as well as complexation. This study presents a simpler and more efficient alternative method for the preparation of pyrazolate MOFs and highlights the power of robust pyrazolate MOFs in sequestrations of radioactive pollutants from water environment.
研究领域:
材料科学
·
环境科学
·
放射化学
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产品关联
DOI
高影响因子
PHYSICS LETTERS A
·
2024
·
IF 2.3
Ting-ting Yan,Yi-fei Xu,Dong-yang Xi,Zhi-qing Yu,Ran Jiang,Dan-dan Zhang
The study investigates the structural stability of the hydrogen-bonded energetic material 4-nitropyrazole (4-NP, C 3 H 3 N 3 O 2 ) from ambient pressure to 10 GPa at room temperature using diamond anvil cell (DAC) and Raman spectroscopy. Based on the changes observed in the high-pressure Raman spectra, it is proposed that the hydrogen-bonded energetic material 4-NP undergoes a phase transition within the pressure range of 2.7–6.4 GPa. Upon complete pressure release from 10 GPa, the resulting spectrum is consistent with the Raman spectrum observed under ambient pressure, indicating that the phase transition is reversible. Ab initio calculations were used to explain the changes in molecular arrangements and hydrogen-bonded networks. Hirshfeld surfaces and fingerprint plots were used to directly compare the variations in packing patterns and intermolecular interactions. Based on the experimental and calculated results, it is proposed that the phase transition of 4-NP was likely caused by the rearrangements of the hydrogen-bonded networks.
研究领域:
材料科学
·
化学
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产品关联
DOI
高影响因子
MOLECULES
·
2019
·Vol. 24
·期 7
·1311
·
IF 3.06
Ming-Jie Chu,Wei Wang,Zi-Li Ren,Hao Liu,Xiang Cheng,Kai Mo,Li Wang,Feng Tang,Xian-Hai Lv
To develop new antibacterial agents, a series of novel triazole-containing pyrazole ester derivatives were designed and synthesized and their biological activities were evaluated as potential topoisomerase II inhibitors. Compound4dexhibited the most potent antibacterial activity with Minimum inhibitory concentration (MIC) alues of 4 µg/mL, 2 µg/mL, 4 µg/mL, and 0.5 µg/mL againstStaphylococcus aureus,Listeria monocytogenes,Escherichia coli, andSalmonella gallinarum, respectively. The in vivo enzyme inhibition assay4ddisplayed the most potent topoisomerase II (IC50= 13.5 µg/mL) and topoisomerase IV (IC50= 24.2 µg/mL) inhibitory activity. Molecular docking was performed to position compound4dinto the topoisomerase II active site to determine the probable binding conformation. In summary, compound4dmay serve as potential topoisomerase II inhibitor.Keywords:pyrazole;triazole;ester;antibacterial;topoisomerase II inhibitor
研究领域:
药理学
·
微生物学
·
药物化学
✓ 已验证
DOI
PubMed
高影响因子
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