MOLECULES
·
2019
·Vol. 24
·期 20
·3718
·
IF 3.06
Mao-Long Chen,Shu-Yang Zhou,Zhou Xu,Li Ding,Yun-Hui Cheng
MIL-100(Fe, Cr) and MIL-101(Cr) were synthesized by the hydrothermal method and applied to the adsorptions of five aromatic amines from aqueous solutions. These three metal-organic frameworks (MOFs) were well characterized by powder X-ray diffraction (PXRD), scanning electron microscope (SEM), transmission electron microscope (TEM), thermogravimetric analysis (TGA) and surface area analysis. The adsorption mechanism of three MOFs and the effects of the structures of MOFs on the adsorption of aromatic amines were discussed. The results show that the cavity system and suitable hydrogen bond acceptor were important factors for the adsorption for five aromatic amines of aniline, 1-naphthalamine, o-toluidine, 2-amino-4-nitrotoluene and 2-nitroaniline: (a) the saturated adsorption capacity of aniline, 1-naphthylamine and o-toluidine on MIL-100(Fe) were 52.0, 53.4 and 49.6 mg/g, respectively, which can be attributed to the intermolecular hydrogen bond interaction and cavity system diffusion. (b) The adsorption capacity of 2-nitroaniline and 2-amino-4-nitrotoluene on MIL-101(Cr) were 54.3 and 25.0 mg/g, respectively, which can be attributed to the more suitable pore size of MIL-101(Cr) than that of MIL-100(Fe, Cr). The MOFs of MIL-100(Fe) and MIL-101(Cr) can be potential materials for removing aromatic amines from aqueous solutions.Keywords:metal-organic framework;adsorption;aromatic amines;aniline;1-naphthalamine;o-toluidine;2-amino-4-nitrotoluene;2-nitroaniline
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
Current Pharmaceutical Analysis
·
2023
·Vol. 19
·期 6
·511-520
·
IF 0.6
Zhang Mengmeng,Zou Qiaogen
Background: Atopic dermatitis (AD) is an allergic skin disease that can be inherited. Crisaborole is a specific drug developed to deal with this disease. The compounds of 4-(4- Bromo-3-formyl-phenoxy)-benzonitrile and 4-(4-(4-bromo-3-formylphenoxy)-3- formylphenoxy) benzonitrile
are the representative impurities in the synthesis of Crisaborole active pharmaceutical in gradient (API). Owing to the genotoxic impurities that could lead to cancer and gene mutations, it is necessary to develop a simple, efficient, sensitive, and accurate method to detect these impurities.
In this study, the 4-(4-Bromo-3-formyl-phenoxy)-benzonitrile and 4-(4-(4- bromo-3-formylphenoxy)-3-formylphenoxy)benzo- nitrile present in Crisaborole API were detected using UPLC-MS/MS. Methods: The separation was made on a ZORBAX Eclipse XDB-Pheny column (4.6 mm ×75mm, 3.5
μm) with the mobile phase of acetonitrile solution containing 0.1% trifluoroacetic acid (A) and water containing 0.1% formic acid (B) in gradient elution mode. Quantification was performed using positive ion electrospray ionization (ESI), and the contents of two compounds were determined
using the multiple reaction monitoring (MRM) modes. Results: The quantitative analytical method was fully validated with respect to linearity (r > 0.9998), sensitivity, precision, accuracy (the average recovery of two impurities was 84.1% to 90.7%), and robustness. Conclusion:
Three batches of samples were detected by UPLC-MS/MS, indicating that the proposed approach was applicable for the quality evaluation of Crisaborole.
研究领域:
药物分析
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皮肤病学
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毒理学
✓ 已验证
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2024
·
IF 4.1
Bo Wang,Peng Li,Zongbo Xie,Zhanggao Le
The photocatalytic hydroxylation of benzene to phenol using low-cost Fe-based materials is of great significance but remains a great challenge for the conversion of benzene in an efficient manner. Here we report a novel method to construct polymeric Fe-BTC-350 with highly dispersed coordinatively unsaturated (CUS) Fe centers by a simple pyrolysis of iron benzene tricarboxylic acid (Fe-BTC) coordination polymer. The CUS Fe centers in Fe-BTC-350 function as Lewis acid sites to accept both electrons and hydroxyl radicals, thus enhancing photocatalytic phenol generation. An optimal phenol yield of 22.7 % has been achieved over optimized Fe-BTC-350 which is 2.8 times that of the Fe-BTC. No evident decay in the activity was found after 4 cycles of consecutive reactions, indicating the robust stability of the photocatalyst. It is expected that the construction of CUS transition metal centers can also be utilized for other photocatalytic radical reactions.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
WATER SCIENCE AND TECHNOLOGY
·
2024
·Vol. 90
·期 10
·2947-2960
·
IF 2.5
Tang Zhi,Yang Sen,Li Yilian,Du Juan,Xiong Yangfu,Fu Shengbo
View large Download slide View large Download slide Close modal Due to rapid urbanization and industrialization, combined pollution caused by BTEX (benzene, toluene, ethylbenzene, and xylene) and heavy metals has become ubiquitous in soils, which would pose serious health risks to humans. However, the effects of heavy metals on the sorption and desorption behaviors of BTEX have not been fully elucidated. In this study, the effects of Cu 2+ and Pb 2+ ions on the sorption and desorption of benzene onto humic acids and black carbons were investigated. The results showed that Cu 2+ and Pb 2+ ions significantly reduced the sorption capacity, slowed down the sorption rate, and made the desorption less hysteretic of benzene on both humic acids and black carbons. Furthermore, the inhibitory effects by Pb 2+ were significantly stronger than those of Cu 2+ . By combining the results of Fourier transform infrared spectroscopy and the site energy distribution model, it can be speculated that the hydration shells of Cu 2+ and Pb 2+ ions partially cover the surface of humic acids and black carbons, blocking their micropores and shielding sorption sites, consequently inhibiting the sorption of benzene. This study highlights that coexisting metal cations can significantly influence the fate of BTEX in soils. The coexistence of Cu 2+ and Pb 2+ ions inhibits benzene sorption and makes desorption less hysteretic onto humic acids (HAs) and black carbon (BCs). The hydration shells of Cu 2+ and Pb 2+ ions hinder the interaction between benzene molecules and the sorption sites. The adsorbed Cu 2+ and Pb 2+ ions block the pores of HAs and BCs and inhibit the pore-filling process of benzene.
研究领域:
环境科学
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土壤学
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产品关联
DOI
PubMed
高影响因子
Catalysts
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2023
·Vol. 13
·期 4
·781
·
IF 3.9
He Sun,Juping Zhang,Kongzhai Li,Hua Wang,Xing Zhu
HighlightsWhat are the main findings?A styrene yield of 91.4% was found for 10% k/CeO2at 500 °C and CO2-O2mixed atmosphere. The excellent catalytic performance of 10% k/CeO2is attributed to the alkali metal oxide modified cerium oxide and carbon dioxide induced oxygen vacancies to promote the dehydrogenation of ethylbenzene.What is the implication of the main finding?The proposed ODH strategy by using oxygen vacancies enriched catalysts offers an important insight into the efficient dehydrogenation of ethylbenzene at mild conditions.AbstractOxidative dehydrogenation (ODH) is an alternative for styrene (ST) production compared to the direct dehydrogenation process. However, ODH with O2or CO2suffers from either over-oxidation or endothermic property/low ethylbenzene conversion. Herein, we proposed an ODH process with a CO2-O2mixture atmosphere for the efficient conversion of ethylbenzene (EB) into styrene. A thermoneutral ODH is possible by the rationalizing of CO2/O2molar ratios from 0.65 to 0.66 in the temperature range of 300 to 650 °C. K modification is favorable for ethylbenzene dehydrogenation, and 10%K/CeO2achieved the highest ethylbenzene dehydrogenation activity due to the enhanced oxygen mobility and CO2adsorbability. The catalyst achieved 90.8% ethylbenzene conversion and 97.5% styrene selectivity under optimized conditions of CO2-4O2oxidation atmosphere, a temperature of 500 °C, and a space velocity of 5.0 h−1. It exhibited excellent catalytic and structural stability during a 50 h long-term test. CO2induces oxygen vacancies in ceria and promotes oxygen exchange between gaseous oxygen and ceria. The ethylbenzene dehydrogenation in CO2-O2follows a Mars-van Krevelen (MvK) reaction mechanism via Ce3+/Ce4+redox pairs. The proposed ODH strategy by using oxygen vacancies enriched catalysts offers an important insight into the efficient dehydrogenation of ethylbenzene at mild conditions.Keywords:ethylbenzene;oxidative dehydrogenation;ceria;CO2
研究领域:
化学工程
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催化科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
·
IF 8.1
Ting Zhang,Weitao Wang,Meng He,Huan Wang,Zhen-Hong He,Yang Yang,Kuan Wang,Zhao-Tie Liu
Imines as valuable chemical intermediates can be synthesized by aerobic photocatalytic oxidation of amines, which is recognized as a promising and green route for imines synthesis. It is attractive to develop solvent-free photocatalytic oxidation of amines with high efficiency, especially with high activity and selectivity, but it is challenging. In the present work, flower-like BiOX/TiO 2 (X = Cl, Br, I) heterojunction was designed for solvent-free photocatalytic oxidation of benzylamine to N-benzylidenebenzylamine. Type II heterojunction of BiOCl/TiO 2 with 67.3 wt% of BiOCl achieved the high formation rate of 6316 µmol∙g −1 ∙h −1 and selectivity of 99 % on BiOCl/TiO 2 . To the best of our knowledge, the activity and selectivity are the highest for solvent-free photocatalytic system. The reason for the varied photocatalytic performances were investigated. The solvent-free photocatalytic mechanism was revealed and proposed. Moreover, the BiOCl/TiO 2 photocatalyst can be used for photocatalytic oxidation of varied benzylamines to imines.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Electrochemical Science
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2023
·
IF 1.5
Shaowen Pei,Xiuping Ju,Jinsheng Zhao,Hongmei Du
Two random copolymers, poly (benzotriazole-indacenodithiophene-benzothiadiazole) (PBTIDBD) and poly (benzotriazole-benzodithiophene-benzothiadiazole) (PBTBDBD) were synthesized and characterized by electrochemistry, spectroelectrochemistry, electrochromic switching, colorimetry and thermal gravimetric analysis. For PBTIDBD, the color of film changed from rosybrown in neutral state to transparent lightgrey in oxidized state. The band gap calculated according to the spectroelectrochemistry data is 1.86 eV, and the response time, optical contrast, coloration efficiency at 1560 nm are 1.04 s, 62.1%, 276.29 cm 2 ∙C -1 , respectively. And, for PBTBDBD, its color changes from rosybrown to transparent grey as it was fully oxidized. The band gap is 1.68 eV, and the response time, optical contrast, coloration efficiency at 1560 nm are 2.68 s, 62.4%, 193.31 cm 2 ∙C -1 , respectively. Both copolymers are stable at a high temperature, and the decomposition temperature of PBTIDBD and PBTBDBD are 463 °C and 326 °C. Both copolymers can be good candidates for electrochromic application.
研究领域:
材料科学
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电化学
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DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2024
·
IF 2.7
Caixia Zhao,Sheng Yang,Tian Fu,Wang Qin,Yaqi Yang,Guoxiang Zou
In order to compare the effect of the monophenyl ring terephthalic acid (TPA) and biphenyl rings 4,4′-oxybisbenzoic acid (OBBA) with ether bond on poly(butylene adipate) (PBA)-based copolyesters properties, two copolyester series poly(butylene adipate- co -butylene terephthalate)s (PBATs) and poly(butylene adipate- co -butylene oxybisbenzoate)s (PBAOs) were synthesized, and comparatively investigated. All the synthesized copolyesters had satisfactory number-average molecular weights in the range of 26,500–73,000 g/mol. For PBATs copolyesters, the crystalline structure gradually transitioned from the monoclinic crystal structure of poly(butylene adipate) to poly(butylene terephthalate) (PBT) with increasing TPA because of the crystalline segments transformation from butylene adipate to butylene terephthalate, while PBAO copolyesters progressively shifted from the crystalline structure of PBA to the amorphous structure of poly(butylene oxybisbenzoate) (PBO) as increasing content of OBBA. The incorporation of either TPA or OBBA comonomers with rigid cyclic structure into PBA chain noticeably increased the glass transition temperature ( T g ). With the same monomer molar ratio, PBAOs because of incorporation of the bicyclic comonomers presented higher T g (range from −24.2 to 49.5°C) than that of PBATs (range from −56.5 to 22.4°C). It was found that copolyesters with bicyclic and ether bond OBBA comonomers exhibited a better flexibility in property than that with monocyclic TPA comonomers.
研究领域:
材料科学
·
高分子化学
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DOI
高影响因子
LIQUID CRYSTALS
·
2013
·
IF 1.959
Lina Zhang,Xinbing Chen,Fengqi Zhao,Xuezhong Fan,Pei Chen,Zhongwei An
Three series of 2-(4′-alkoxybiphenyl-4-yl)-1H-benzimidazole derivatives (nM-x), which possessed 5-nitrobenzimidazole (nM-N series), benzimidazole (nM-H series) or 5-methylbenzimidazole (nM-M series) units at the end of the molecule, were synthesised and characterised by infrared, 1H- and 13C-nuclear magnetic resonance spectra, electrospray ionisation-mass spectrometry and elemental analysis. Their phase transition behaviour was investigated by differential scanning calorimetry, polarising optical microscopy and X-ray diffraction. All the compounds exhibited enantiotropic smectic mesophases with wide temperature domains for a carbon number in the alkoxy chain from 6 to 16, where the mesophase ranges were 14–91°C and 17–99°C during heating and cooling processes for the nM-N compounds, 7–25°C and 8–49°C for the nM-H compounds and 48–81°C and 52–85°C for the nM-M compounds, respectively. The effect of the length of alkoxy chain on mesomorphic properties was discussed. The nM-N and nM-M exhibited a much wider mesophase range whether during heating or cooling process than the corresponding nM-H series, especially for the longer terminal chain (n > 8), which indicated that the substituent in the benzimidazole moiety was helpful in increasing the mesophase stability.
研究领域:
有机化学
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材料科学
✓ 已验证
DOI
高影响因子
ORGANIC PROCESS RESEARCH & DEVELOPMENT
·
2018
·
IF 3.584
Jie Zhang,Lei Wang,Chuang Li,Shaohua Jin,Changhai Liang
Direct selective hydrogenolysis of dibenzofuran (DBF) derived from coal and shale oil to a value-added chemical, ortho-phenylphenol (OPP), with high selectivity (80%) and yield (48%) has been achieved over Pt/MgO at 400 °C and 1.0 MPa by controlling the C–O bond cleavage as well as minimizing the extent of hydrogenation of aromatic rings. Meanwhile, Pt/SiO2, Pt/Al2O3, and Pt/MgO/Al2O3 catalysts were used for the DBF hydrogenolysis and showed lower selectivity for OPP. The influence of reaction parameters has been studied to unveil the optimal reaction conditions. And the phenomenon of OPP dehydrogenation is found over various catalysts for the hydrogenation reaction of OPP. Extensive reactions and catalyst characterizations demonstrated that the OPP selectivity and the dehydrogenation of OPP to DBF follows the order of supports basicity: MgO-900 > MgO > SiO2 > MgO/Al2O3 > Al2O3, which shows that the acid–base properties of supports impact the adsorption and desorption behaviors of DBF and OPP, and results in the disparity of OPP selectivity and the dehydrogenation of OPP. Finally, a plausible reaction pathway and mechanistic understanding are proposed.
研究领域:
催化化学
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能源化学
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产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2021
·
IF 2.694
Jiahai Ding,Wei Guan,Leiyu Zhang,Xiudong Zhang,Chundong Zhang,Lei Wang,Hui Wan,Guofeng Guan
Isobaric binary vapor–liquid equilibrium (VLE) data for ethylbenzene + ethyl benzoate, o-xylene + ethyl benzoate, m-xylene + ethyl benzoate, and p-xylene + ethyl benzoate, as well as the quinary VLE data for ethyl benzoate + o-xylene + m-xylene + p-xylene + ethylbenzene, were measured at 101.33 kPa using a modified Rose still. The thermodynamic consistency test was implemented by using the Herington method. Moreover, the VLE data for ethyl benzoate + o-xylene, ethyl benzoate + m-xylene, ethyl benzoate + p-xylene, and ethyl benzoate + ethylbenzene were correlated using the nonrandom two-liquid (NRTL) and universal quasichemical activity coefficient (UNIQUAC) models using the nonlinear least-square method. The obtained NRTL and UNIQUAC model parameters of the binary systems were utilized to predict the VLE data for the quinary system. It was shown that all the models showed a relatively small deviation from the experimental results, and the quinary predicted values obtained in this way agreed well with the experimental values, indicating that the experimental data were suitable for designing the extractive distillation process of ethyl benzoate with ethylbenzene and xylene isomers.
研究领域:
化学工程
·
热力学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 7
·2890-2896
·
IF 3.288
Yinhui Yang,Meiling Qi,Jinliang Wang
Here we report a novel hexaphenylbenzene (HPB)-based material functionalized with six tetraphenylethylene units (BPT) with unique conformation-driven selectivity for gas chromatographic (GC) separations. It is composed of a neat aromatic hydrocarbon with a rigid propeller-like conformation. As a result, the BPT capillary column exhibited high column efficiency of 5340 plates per m and high-resolution capability for aromatic to aliphatic isomers with excellent intra-day and inter-day repeatability and between-column reproducibility. The results demonstrate the unique conformation-driven selectivity of the HPB-based stationary phase, which is rarely reported for chromatography. Moreover, its application in the determination of isomer impurities in commercial products proved its good potential for practical GC analysis. This work presents a new perspective for developing selective stationary phases by engineering their structures.
研究领域:
分析化学
·
材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）