LIQUID CRYSTALS
·
2018
·
IF 2.636
Liyuan Ren,Longyan Duan,Qiang Weng,Pei Chen,Yafei Hou,Aiai Gao,Xinbing Chen,Zhongwei An
A series of 1-methyl-1H-benzimidazole-based compounds, 2-(4ʹ-alkoxy-1,1ʹ-biphenyl-4-yl)-1-methyl- 1H-1,3-benzimidazole derivatives (nPPMx-M) with terminal hydrogen, methyl and nitro moieties (coded as nPPMH-M, nPPMM-M and nPPMN-M, respectively), were prepared and their structures were characterised. The compounds display enantiotropic smectic mesophases for hydrogen and methyl terminated compounds (nPPMH-M and nPPMM-M), and enantiotropic nematic mesophases for nitro terminated compounds (nPPMN-M) with short alkoxy chain below than 10 carbon atoms, where the mesophase ranges are 24–72°C and 74–104°C on heating and cooling processes for nPPMH-M, 90–119°C and 110–135°C for nPPMM-M, and 102–129°C and 113–207°C for nPPMN-M, respectively. It is noted that the compounds nPPMx-M exhibit much lower melting points and much wider mesophase range both in heating and cooling than non-1-methyl substituted analogs, which are ascribed to the disruption of hydrogen bonding among the molecules caused by methyl substitution at 1-position of benzimidazole. Meanwhile, among the compounds nPPMx-M, much wider mesophase ranges are obtained for nPPMM-M and nPPMN-M, indicating a much high mesophase stability for the compounds bearing terminal moiety (CH3 and NO2).
研究领域:
材料化学
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物理化学
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DOI
高影响因子
Atmosphere
·
2022
·Vol. 13
·期 6
·970
·
IF 3.11
Xin Lin,Mingqiang Huang,Tingting Lu,Weixiong Zhao,Changjin Hu,Xuejun Gu,Weijun Zhang
Imidazole compounds are important constituents of atmospheric brown carbon. The imidazole components of aqueous secondary organic aerosol (aqSOA) that are generated from the evaporation of droplets containing pyruvaldehyde and inorganic ammonium are on-line characterized by an aerosol laser time-of-flight mass spectrometer (ALTOFMS) and off-line detected by optical spectrometry in this study. The results demonstrated that the laser desorption/ionization mass spectra of aqSOA particles that were detected by ALTOFMS contained the characteristic mass peaks of imidazoles at m/z = 28 (CH2N+), m/z = 41 (C2H3N+) and m/z = 67 (C3H4N2+). Meanwhile, the extraction solution of the aqSOA particles that were measured by off-line techniques showed that the characteristic absorption peaks at 217 nm and 282 nm appeared in the UV-Vis spectrum, and the stretching vibration peaks of C-N bond and C=N bond emerged in the infrared spectrum. Based on these spectral information, 4-methyl-imidazole and 4-methyl-imidazole-2-carboxaldehyde are identified as the main products of the reaction between pyruvaldehyde and ammonium ions. The water evaporation accelerates the formation of imidazoles inside the droplets, possibly owing to the highly concentrated environment. Anions, such as F−, CO32−, NO3−, SO42−and Cl−in the aqueous phase promote the reaction of pyruvaldehyde and ammonium ions to produce imidazole products, resulting in the averaged mass absorption coefficient () in the range of 200–600 nm of aqSOA increases, and the order of promotion is: F−> CO32−> SO42−≈ NO3−≈ Cl−. These results will help to analyze the constituents and optics of imidazoles and provide a useful basis for evaluating the formation process and radiative forcing of aqSOA particles.Keywords:pyruvaldehyde;inorganic ammonium;aqueous secondary organic aerosol;imidazole compounds;brown carbon
研究领域:
大气化学
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环境科学
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DOI
高影响因子
Frontiers in Chemistry
·
2022
·
IF 5.545
Zheng Min,He Huiting,Li Xiangzhou,Yin Dulin
Keggin-type phosphotungstic acid (HPW) supported on imidazolyl-activated carbon (AC-COIMI-HPW) catalysts was prepared, which was used to catalyze the oxidation of benzyl alcohol with aqueous H2O2. In the presence of AC-COIMI-HPW, the benzyl alcohol conversion of 90.2% with 91.8% selectivity of benzaldehyde was obtained at 90°C for 6 h in an acetonitrile aqueous solution. The catalyst exhibited an outstanding performance for the oxidation of various benzyl alcohols and aliphatic alcohols. In addition, the catalyst could be easily recovered and reused five times without significant deactivation. The characterization results showed that HPW was chemically bonded on the surface of the carbon material through an ionic bond. It is proposed that the combination of the imidazole cation with the HPW anion could not only tune the redox catalytic properties of the PW anion but also enhance the compatibility of the catalyst in the reaction medium, thereby improving the catalytic performance.
研究领域:
催化化学
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材料科学
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绿色化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
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2023
·
IF 3.8
Xingxin Xu,June Qu,Hualiang Huang
In this work, a low-cost and easily purified small molecule dibenzimidazole compound (BBI) was synthesized by the condensation of o-phenylenediamine and malonic acid. BBI was a new corrosion inhibitor for magnesium alloys and its corrosion inhibition behavior on AZ91D magnesium alloy was studied by electrochemical measurements, surface analysis and theoretical calculations in 3.5 wt.% NaCl solution at 30 °C. The adsorption behavior and corrosion inhibition mechanism of BBI molecules were discussed. It was found that BBI exhibited excellent inhibition effect on the corrosion of magnesium alloy. When BBI concentration was 0.25 g/L, the optimal corrosion inhibition efficiency was 86.2%. The adsorption of BBI molecule obeyed Langmuir adsorption on the surface of magnesium alloy, and one side of BBI molecule was adsorbed on the surface of magnesium alloy in parallel through physical and chemical mixed adsorption.
研究领域:
材料科学
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电化学
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理论计算
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产品关联
DOI
高影响因子
JOURNAL OF MEMBRANE SCIENCE
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2021
·
IF 8.742
Chi Jiang,Zhaohui Fei,Mengmeng Zhang,Xiupeng Ma,Yingfei Hou
Highly permeable thin-film composite (TFC) reverse osmosis (RO) membranes are desirable for desalination and water reuse. Various interlayers have been developed to improve water permeance of TFC nanofiltration (NF) membranes, however the traditional interlayer strategy trends not to work well for RO membranes. Herein, a novel interlayer with transformable wettability , and with function of releasing “placeholder” agent is designed for the fabrication of high-permeance RO membrane. The initial interlayer provides an instable hydrophobic surface for interfacial polymerization (IP) to facilitate the formation of a rough separation layer containing interior nanovoids, and then it translates into a hydrophilic “gutter” layer through simple water immersion to further enhance the overall transport efficiency of the TFC membrane. In addition, the interlayer can in-situ release imidazole component to participate in the IP reaction, which is proven to influence the intrinsic properties of the membrane materials due to the unique acyl-transfer property of N -acyl imidazole. As a result, the water permeance of the as-fabricated RO membrane is up to 5.87 L m −2 h −1 bar −1 , nearly 6-fold enhancement compared to the control group, while still maintaining comparable rejection toward NaCl, thus successfully overcoming the permeability-selectivity trade-off limit. This work paves a new way for preparing high-performance RO membrane.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MEDICINAL CHEMISTRY
·
2024
·
IF 6.8
Ting Xu,Xiaoting Yan,Ayue Kang,Longhua Yang,Xinhui Li,Yue Tian,Ruige Yang,Shangshang Qin,Yong Guo
The escalation of multidrug-resistant bacterial infections, especially infections caused by methicillin-resistant Staphylococcus aureus (MRSA), underscores the urgent need for novel antimicrobial drugs. Here, we synthesized a series of amphiphilic 2-phenyl-1H-phenanthro[9,10-d]imidazole-antimicrobial peptide (AMP) mimic conjugates (III1–30). Among them, compound III13 exhibited excellent antibacterial activity against G+ bacteria and clinical MRSA isolates (MIC = 0.5–2 μg/mL), high membrane selectivity, and low toxicity. Additionally, compared with traditional clinical antibiotics, III13 demonstrated rapid bactericidal efficacy and was less susceptible to causing bacterial resistance. Mechanistic studies revealed that III13 targets phosphatidylglycerol (PG) on bacterial membranes to disrupt membrane integrity, leading to an increase in intracellular ROS and leakage of proteins and DNA, ultimately causing bacterial cell death. Furthermore, III13 possessed good fluorescence properties with potential for further dynamic monitoring of the antimicrobial process. Notably, III13 showed better in vivo efficacy against MRSA compared to vancomycin, suggesting its potential as a promising candidate for anti-MRSA medication.
研究领域:
微生物学
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药物化学
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感染病学
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产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
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2025
·
IF 6.7
Xinxin Zheng,Sidi Cun,Jiatai Yin,Xue Zhao,Yunshan Wang,Jing Wang,Qian Li,Xinfeng Zhao
The sensitivity, selectivity, and accuracy of immobilized protein-based methods are critically dependent on the strategies employed for protein immobilization. Compared with random immobilization approaches, site-specific covalent methods have emerged as promising alternatives, offering enhanced analytical performance. However, these methods typically require genetic modification of the target protein to incorporate a specific tag or prior purification of the protein, posing significant challenges for immobilizing endogenous proteins. Herein, we address these limitations by using the 5-hydroxytryptamine transporter (5-HTT) as a model system. We designed a probe by conjugating fluvoxamine─a specific ligand of 5-HTT─with either a fluorescent reporter or aminopropyl-modified silica gel through an alkyl linker containing an acyl imidazole moiety as the reactive group. By introducing ligand-directed acyl imidazole (LDAI) chemistry, we achieved selective labeling of 5-HTT in live cells and endogenous 5-HTT immobilization without purification in advance. Labeling experiments confirmed the high specificity and favorable kinetics of the LDAI ligands toward 5-HTT. Chromatographic analysis revealed significant improvements in selectivity (5.7–50.9-fold), resolution (1.2–3.0-fold), and sensitivity (1.0–12.0-fold) for analyzing canonical ligands when using immobilized endogenous 5-HTT, compared to His-tagged and Halo-tagged recombinant proteins. This approach, by substituting fluvoxamine with other ligands in the probe, can be generalized for the labeling and immobilization of a wide range of endogenous proteins, offering a versatile platform for advanced protein-based analytical techniques.
研究领域:
生物化学
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分析化学
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药物化学
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产品关联
DOI
PubMed
高影响因子
Journal of Coatings Technology and Research
·
2023
·Vol. 20
·期 6
·1867-1880
·
IF 2.3
Xue Tao,Yu Caili,Zhou Zhongqun,Zhang Faai
Achieving functional styrene–maleic anhydride (SMA) copolymer dispersant is highly attractive but still remains a challenge. Conventional modified SMA dispersants have complex modification steps, poor performance, and limited applications. Thus, a series of styrene–maleimide (SMI) copolymers with different functionality as amphiphilic dispersants for dispersing nano-SiO 2 in an aqueous solution were synthesized using a simple preparation process. The changes in the maleic anhydride groups during imidization were tracked using FTIR spectroscopy, 1 H-NMR, and GPC. A rotational viscometer and an inverted bottle method were used to measure the viscosity and coagulation time of the nano-SiO 2 aqueous dispersion system, respectively, after adding the SMI dispersants. The particle size, size distribution, and dispersant adsorption amount of the dispersion were analyzed using laser particle size analysis; FTIR spectroscopy and SEM; and TGA, respectively. The results showed that the hydrogen bonds formed between the amino groups in the dispersant and the hydroxyl groups on the SiO 2 surface during stirring allowed the dispersant to be adsorbed onto the SiO 2 surface after being added to the nano-SiO 2 aqueous system. The addition of the SMI dispersant enhanced the steric hindrance and electrostatic repulsion between the nanoparticles, thus making it possible for the SiO 2 nanoparticles not to easily aggregate in water, improving their dispersity and stability. Additionally, the type and amount of SMI dispersant used significantly affected the SiO 2 nanoparticles' ability to disperse in water. This makes SiO 2 particles convenient to use and transport, not produce dust pollution, and easy to store. Graphical abstract
研究领域:
高分子化学
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纳米技术
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材料科学
·
表面化学
·
胶体科学
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2025
·
IF 4.7
Yan-Li Lu,Yue Ma,Xi-Nan Yang,Jie Gao,Xiao-Qian Chen,Xin Xiao,Pei-Hua Ma
In this paper, a crystalline supramolecular organic framework was constructed based on cyclopentanocucurbit[6]uril (CyP 6 Q[6]) and five benzimidazole compounds [2-aminobenzimidazole (G1), 2-methylbenzimidazole (G2), 2-hydroxymethylbenzimidazole (G3), 2-phenylbenzimidazole (G4), 2-(2-pyridyl) -benzimidazole (G5)] through host-guest interaction, with the Single crystal X-ray diffraction analysis showing that CyP 6 Q[6] and Gn(n=1-5) formed 1:1 host-guest inclusion complexes by hydrogen bonding, respectively. The type of substituent (R group) in the guest determines the mode of interaction with CyP6Q[6], where the benzimidazole rings of G1-G4 are encapsulated in the cavity of CyP6Q[6] with the R group located outside its ports, whereas the R group (pyridinyl group) of G5 enters the cavity of CyP6Q[6] with the benzimidazole ring exposed outside its ports. Interestingly, under the ion-dipole interaction, the inclusion complexes form an '8′ shaped supramolecular organic framework by stacking, and due to the different characteristics of the R group and the binding mode, supramolecular channels with different sizes are formed.
研究领域:
超分子化学
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晶体工程
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材料科学
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主客体化学
·
X射线衍射分析
✓ 已验证
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2018
·
IF 2.011
Feng Su,Ziqing Sun,Weike Su,Xianrui Liang
The tautomerism of three benzimidazole compounds: Omeprazole sulfide, 1 , (R)-Lansoprazole, 2 , and Omeprazole sulfone , 3 were investigated by NMR with the effect of variant solvents and temperature. The dielectric constant of the medium and the ability of solvents to form hydrogen bond with the tautomer had a profound effect on the tautomeric equilibration. The chemical shifts and resonance lines of compounds 1–3 differed greatly in different solvent system mainly due to intra- and intermolecular hydrogen bonds. Variable temperature-nuclear magnetic resonance (VT-NMR) experiments showed that at 203 K the two tautomers of compound 1 were separated and determined to be 6:4 and those of compound 3 be 7:3. In contrast, compound 2 presented only one tautomer at the same temperature while the tautomerism was observed again with temperature increasing. The free energy of activation of the tautomeric interchange of compounds 1 – 3 were 13.77 kcal/mol, 13.47 kcal/mol and 13.06 kcal/mol, respectively. Density function theory (DFT) calculations results showed the tautomers of compound 2 had higher energy differences among the three compounds demonstrating only one preferred conformation existed at 203 K. The preferred conformations of compounds 1 and 3 were also given.
研究领域:
化学
·
物理化学
·
光谱学
·
理论化学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）