Reaction Chemistry & Engineering
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2024
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IF 3.4
Minmin Liu,Bingxi Song,Yanhui Hu,Xianglei Meng,Renzheng Jiang,Yanyan Diao,Yuting Song
Following the principle of sustainable and green development, the environmentally friendly and highly efficient manufacturing of fluorine chemical products is becoming an unavoidable development trajectory. Ionic liquid catalysts have shown great potential to replace traditional metal salt catalysts, which cause environmental pollution, in the dimerization of perfluorinated olefins. In this study, a series of strong nucleophilic thiocyanate ionic liquids with various cationic structures were designed and synthesized. The catalytic activity of 4-dimethylaminopyridine (DMAP) ionic liquids exceeded that of reported catalysts, being 2.4 times higher than that of traditional metal salt catalysts, and 1.5 times higher than that of imidazole ionic liquids reported in the literature. Under the optimal reaction conditions, the high turnover frequency (TOF) value of the [C6DMAP][SCN] catalyst performance reaches 325.04 h−1. Based on the experimental results, density functional theory (DFT) and XPS analysis, the excellent catalytic performance of [C6DMAP][SCN] can be attributed to the dual active sites of anions and cations, and a dual-activation reaction mechanism is further proposed. This study not only expands the application of ionic liquid in the hexafluoropropylene dimerization reaction but also helps establish a more efficient, green, and sustainable catalytic process for hexafluoropropylene dimerization.
研究领域:
化学工程
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绿色化学
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材料科学
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产品关联
DOI
高影响因子
Arabian Journal of Chemistry
·
2017
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IF 4.553
Bibimaryam Mousavi,Somboon Chaemchuen,Suphot Phatanasri,Cheng Chen,Cheng Zeng,Rakesh Ganguly,Serge Zhuiykov,Francis Verpoort
Glycerol can be converted to valuable products such as epichlorohydrin which is an important intermediate applied in various industries. For example, dioxane derivatives, which are important pharmaceuticals, can be obtained from epichlorohydrin. In the present study, ZIF-8, ZIF-67, MIL-100, and UiO-66 were applied for the direct cyclodimerization of epichlorohydrin. These MOFs were selected because they were already applied as active catalysts in ring opening of epoxides. Among them, ZIF-8 showed the highest activity and selectivity in the absence of any solvent or co-catalyst. Using ZIF-8 as a catalyst, the cyclodimer product (1,4-dioxane 2,5-bis-chloromethyl) was obtained in a yield of about 70% which was significantly superior to previous homo or heterogeneous catalysts for this reaction. Due to ZIF-8 structure and the proposed mechanism, the cyclodimerization reaction catalyzed either by the defects in the structure and/or on the surface. Furthermore, acidic-basic characteristics were also in play. The NH 3 and CO 2 temperature-programed desorption technique were utilized to identify the active sites and thereby reaction mechanism. Moreover, because of similar properties of ZIF-8 to zeolites, the activity of commercial ZSM-5 for the same reaction was also investigated in this work.
研究领域:
化学工程
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材料科学
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DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
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2018
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IF 2.891
Xueqin Wei,Xingke Yu,Yuxue Zhang,Wenting Liang,Jiecheng Ji,Jiabin Yao,Ming Rao,Wanhua Wu,Cheng Yang
A series of primary-face- or secondary-face-modified β-cyclodextrins (CDs) 7 - 11 were prepared for mediating the enantiodifferentiating [4 + 4] photocyclodimerization reactions of 2-anthracenecarboxylic acid (AC). The complexation behavior of these hosts with AC was studied by 1 H NMR, UV–vis, circular dichroism spectroscopy and ITC titration. The product distribution and product’s ee turned out to be a critical function of the skeleton and periphery modifications of β-CD. The combined yields of slipped cyclodimers 5 and 6 were greatly enhanced in the presence of modified β-CDs. In contrast to native β-CD and other β-CD derivatives, host 9, in which a phenyltriazolyl group was introduced on the primary face of β-CD, afforded antipodal cyclodimer 6 in a much higher enantioselectivity of 46% ee. The influence of temperature and salt additives were investigated in depth. Intriguingly, product chirality was switched by temperature in the presence of 6 M CsCl. Under an optimized condition, host 8 gave slipped cyclodimer 6 in 70% ee, which is the highest enantioselectivity ever reported for the slipped cyclodimer.
研究领域:
有机化学
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超分子化学
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DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2018
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IF 3.141
Wenhua Xu,Yuanhai Su,Yang Song,Minjing Shang,Li Zha,Qinghua Lu
Cyclobutanetetracarboxylic dianhydride (CBDA) was prepared by photodimerization of maleic anhydride in capillary microreactors within Taylor flow under UV irradiation. Both inert gas and ultrasound were introduced into this photochemical process to avoid the potential channel clogging resulting from the CBDA deposition. Higher input power of the Hg lamp, lower reactant concentration, longer residence time, and smaller inner diameter of the capillary were found to result in higher CBDA yield. The yield of CBDA could reach as high as 66.3% at an actual residence time of 30 min in the capillary microreactor with 0.5 mm inner diameter. According to the analysis of energy conversion, only low effective photoelectric transformation efficiencies could be achieved in this photochemical process. However, the photonic efficiency for this photodimerization carried out in capillary photomicroreactors was much higher compared to batch photoreactors and was comparable with that for other photochemical transformations using similar photomicroreactors and light sources.
研究领域:
化学工程
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光化学
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产品关联
DOI
高影响因子
Journal of Flow Chemistry
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2022
·Vol. 12
·期 1
·91-100
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IF 3.264
Xu Wenhua,Pan Yizhe,Chen Liuyang,Su Yuanhai,Shang Minjing,Lu Xuemin,Lu Qinghua
The combination of continuous-flow microreactors and photoreaction is one of the important researches in flow chemistry. Dimethyl-substituted cyclobutanetetracarboxylic dianhydride (DM-CBDA) was prepared through photodimerization in photomicroreactors and applied in the preparation of polyimide films. It was found that ethyl acetate as the solvent and an appropriate concentration of substrate could benefit this photodimerization process in the capillary photomicroreactor. Higher photonic efficiency and higher DM-CBDA yield were obtained in the photomicroreactor as compared to batch photoreactors. DM-CBDA was applied to prepare the colorless transparent polyimide films, which showed a high polymerization activity for the preparation of poly(amic acid) with high molecular weight. A PI film of DM-CBDA/ODA with the UV cutoff wavelength of 295 nm, the glass transition temperature of 376 °C, and the elongation at break of 11.3% was prepared. This work broadens the application of photomicroreactors for the preparation of polyimide monomers in flow chemistry and its films with good transparent, thermal and mechanical properties.
研究领域:
材料化学
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高分子科学
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产品关联
DOI
高影响因子
Nature Communications
·
2024
·Vol. 15
·期 1
·1-11
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IF 14.7
Li Wei,Zhang Menghang,Sun Xinyi,Sheng Chuanchao,Mu Xiaowei,Wang Lei,He Ping,Zhou Haoshen
Li-CO 2 batteries offer a promising avenue for converting greenhouse gases into electricity. However, the inherent challenge of direct electrocatalytic reduction of inert CO 2 often results in the formation of Li 2 CO 3 , causing a dip in output voltage and energy efficiency. Our innovative approach involves solid redox mediators, affixed to the cathode via a Cu(II) coordination compound of benzene-1,3,5-tricarboxylic acid. This technique effectively circumvents the shuttle effect and sluggish kinetics associated with soluble redox mediators. Results show that the electrochemically reduced Cu(I) solid redox mediator efficiently captures CO 2 , facilitating Li 2 C 2 O 4 formation through a dimerization reaction involving a dimeric oxalate intermediate. The Li-CO 2 battery employing the Cu(II) solid redox mediator boasts a higher discharge voltage of 2.8 V, a lower charge potential of 3.7 V, and superior cycling performance over 400 cycles. Simultaneously, the successful development of a Li-CO 2 pouch battery propels metal-CO 2 batteries closer to practical application.
研究领域:
电化学
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材料科学
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能源存储
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产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2023
·Vol. 25
·期 14
·5438-5448
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IF 9.8
Shiqi Huang,Xianglei Meng,Yanzhao Gao,Minmin Liu,Junjie Zhang,Yu Zhou,Yuting Song,Yanyan Diao
According to the requirements of sustainable green development, the efficient green synthesis of fluorine chemical products is an inevitable trend. In this work, we used ionic liquids as an effective catalyst in an important fluorochemical reaction – hexafluoropropylene dimerization for the first time. The effects of ionic liquids with different spatial positions, substituents and nucleophilic anions on the catalytic performance of hexafluoropropylene dimerization were systematically studied. The results showed that the strong nucleophilic trisubstituted thiocyanate imidazole ionic liquid [C6mmim][SCN] had the highest activity under the optimum reaction conditions, the turnover frequency (TOF) was 108.36 h−1 and the selectivity was 97.96%. Compared with the traditional metal salt catalyst system, the catalytic activity of ionic liquids was double. In addition, based on the XPS analysis results and density functional theory (DFT), a possible reaction mechanism was proposed. The effective catalytic activity of ionic liquids was mainly attributed to the strong nucleophilicity of anions and the weak interaction between cations and anions. This work will successfully provide a green synthesis route for hexafluoropropylene dimerization and further promote the efficiency and greening of fluorine chemical reactions.
研究领域:
化学工程
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催化
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绿色化学
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氟化学
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产品关联
DOI
高影响因子
International Journal of Electrochemical Science
·
2025
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IF 2.4
Tong Li,Baokang Jin,Changpeng Lv,Xuemei Shen,Mei Yang
Quinone is a bioactive compound present in some traditional Chinese medicines and participates in numerous biological processes. The carbonyl group in quinone serves as the active center in electrochemical reactions, functioning as an excellent carrier of electron transfer. In this study, in situ Fourier transform infrared (FT-IR) spectroelectrochemistry enables the real-time tracking of three-dimensional (3D) information at molecular level of different substances throughout the electrochemical process. The detection of absorption peaks corresponding to dimerization and hydrogen bonding in the Fourier transform infrared 3D spectra proves that the electrochemical reduction of duroquinone (DQ) in anhydrous acetonitrile involves dimer formation and development of intramolecular hydrogen bonds within monovalent anion radicals. Con sistent with these findings, cyclic voltammetry reveals two pairs of redox peaks and one irreversible anodic peak. Surprisingly, ionic liquids with complex structures of ions, such as 1-butyl-3-methylimidazolium tetrafluoroborate (BMIMBF 4 ) and 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF 6 ), make the reduction simpler. Conversely, the transformation of DQ to DQ •- and subsequently to DQ 2- without dimer or hydrogen bond occurring, as clearly observed in the infrared cyclic voltabsorptometry (CVA) and derivative cyclic voltabsorptometry (DCVA). DQ undergoes a straightforward, sequential two-step, one-electron transfer process facilitated by the unique composition of ionic liquids, potentially prompting further evaluation of the roles of cations and anions in ionic liquids.
研究领域:
电化学
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光谱学
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分析化学
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物理化学
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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）