JOURNAL OF ORGANIC CHEMISTRY
·
2021
·
IF 4.354
Yuxiu Li,Xiangqian Li,Xiaowei Li,Dayong Shi
The straightforward synthesis of α-fluoro-β-arylalkenyl sulfones under transition-metal- and base-free conditions has been described, which displays broad functional group compatibility and high stereoselectivity. In particular, the strategy is also applied to the late-stage modification of complex natural products and drugs.
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2016
·
IF 2.196
Lejun Feng,Danxing Zheng,Weijia Huang
In this work, three new working pairs, {fluoroethane (HFC161) + dimethylether tetraethylene glycol (DMETEG)}, {HFC161 + dimethylether triethylene glycol (DMETrEG)} and {HFC161 + dimethylether diethylene glycol (DMEDEG)}, are proposed for absorption power cycle. The working pairs are assessed from both thermodynamics and thermokinetic perspective. By combining the microcalorimetry and isothermal synthesis methods, an experimental apparatus was developed to simultaneously obtain the microcalorimetry and vapour–liquid equilibrium data. Then, the solubility and absorption enthalpy data of the three new working pairs were sync-measured at 303.15 K by this sync-measurement experimental apparatus. The thermodynamics data indicated that the affinities of the three working pairs increased from strong to weak in the following order: HFC161 + DMETEG > HFC161 + DMETrEG > HFC161 + DMEDEG. Then the thermokinetic parameters of the absorption rate constant and activation energy were analysed based on the thermokinetic experiment at (303.15, 313.15, 323.15, and 333.15) K. As a result, the affinities of the three working pairs are consistent with the previous thermodynamics study. In addition, the intermolecular interactions within the three systems were analysed according to the intermolecular hydrogen bonds; overall, the (HFC161 + DMETEG) system is considered to be the potential option for applications.
研究领域:
化学工程
·
热力学
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产品关联
DOI
高影响因子
LIQUID CRYSTALS
·
2017
·
IF 2.661
Longyan Duan,Dingqian Shi,Pei Chen,Kun Hu,Liyuan Ren,Xinbing Chen,Zhongwei An
Series of laterally multifluorinated heterocyclic compounds, 2-(2ʹ,3-difluoro-4ʹ-alkoxy-1,1ʹ-biphenyl-4-yl)-benzoxazole derivatives (nPF(2)PF(3)Bx), are prepared and characterised. They mainly display enantiotropic nematic mesophases with wider mesophase ranges of 12–107°C (heating process) and 22–134°C (cooling process) than the corresponding analogues. The enhanced nematic mesophase stability is achieved via slightly increasing inter-ring twist angle with inter-ring lateral fluorine substitute in biphenyl unit, as well as through improving the molecular polarity with multifluorine substitutes. Meanwhile, two inter-ring lateral fluorine atoms lead to a decrease in melting/clearing points and a wide nematic mesophase range, which makes it possible for heterocyclic mesogens nPF(2)PF(3)Bx to use in nematic liquid crystal display mixtures.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
CORROSION SCIENCE
·
2020
·
IF 6.479
Cheng Li,Yuan Li,Xiao Wang,Sicheng Yuan,Dan Lin,Yanji Zhu,Huaiyuan Wang
It is difficult for ordinary coatings to meet the long-term anti-corrosion requirements of modern industry. Incorporating high-performance fillers into those coatings is considered as an effective way to solve the problem. Herein, a new hydrophobic fluoro-substituted polyaniline (PFAN) filler with high-performance was successfully synthesized. Results showed that the filler synthesized at 0 ℃ exhibited nearly two-dimensional micro-fibrous morphology and good solubility in some common solvents. Results also revealed that the fabricated filler could passivate iron and prevent electrolyte penetration. All these advantages endowed the epoxy coating containing 3 wt% PFAN with exceptional long-term anti-corrosion performance.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2022
·
IF 6.206
Cheng Li,Xiao Wang,Meng Zhang,Yue Sun,Yexiang Cui,Yanji Zhu,Huaiyuan Wang
Inert inorganic anti-corrosion fillers enjoy the advantages of stable performance, but most of them face the problems of poor compatibility and disability. Therefore, strategies about addressing the above problems need to be developed. Herein, based on interface enhancement strategy, one typical inert inorganic filler h-BN was armed with fluoro-substituted polyaniline (PFAN). To this end, diazotization reaction was utilized to introduce aniline group to h-BN, and emulsion polymerization was employed to grow the micro-size copolymer of aniline and 2-fluoroaniline. Benefitting from the above interface enhancement attempt, the compatibility of h-BN with resin was enhanced, which was explained by the chemical armed PFAN participated in the curing process of epoxy. Moreover, the disability of h-BN was also improved owed to this interface armor. Therefore, combining the fully developed barrier properties of h-BN with passivate ability of PFAN, the coating containing a small addition amount (0.9 wt%) of the composite fillers to epoxy coatings significantly improved their long-term corrosion resistance , which was confirmed by the EIS result that its low frequency impedance value was maintained above 10 10 and was about 10 3 times larger than that of pure EP coating after being immersed in 3.5 wt% NaCl solution for 120 days.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
LIQUID CRYSTALS
·
2014
·
IF 2.349
Kun Hu,Yiwei Xu,Pei Chen,Aiai Gao,Weisong Du,Xinbing Chen,Zhongwei An
Series of fluorinated compounds, 2-(3′,5′-difluoro-4′-alkoxybiphenyl-4-yl)-benzoxazole derivatives (nFBx), were prepared and characterised. Their phase transition behaviour was investigated by differential scanning calorimetry and polarising optical microscopy. In the case of carbon atoms in the alkoxy chain between 4 and 10, they exhibited enantiotropic mesophases with the mesophase ranges of 12–119°C and 23–152°C on heating and cooling for compounds bearing different substituents (H, CH3, Cl, and NO2). With the exception of nitro-substituted compounds, the nFBx series displayed intense photoluminescence emission at 380–385 nm in methylene chloride solution when they were excited at their absorption maxima. Compared to non-fluorinated analogues, fluorinated compounds nFBx (apart from nitro-substituted compounds) exhibited much lower melting points, but comparable or slightly narrower mesophase ranges during both heating and cooling, which were attributed to the disruption of the side-to-side intermolecular packing caused by the two lateral fluoro substituents.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 8
·期 4
·2066-2073
·
IF 10.733
Chuankai Fu,Yulin Ma,Shuaifeng Lou,Can Cui,Lizhi Xiang,Wei Zhao,Pengjian Zuo,Jiajun Wang,Yunzhi Gao,Geping Yin
Succinonitrile (SN)-based electrolytes are attractive due to their considerable ionic conductivity and high oxidative stability. However, the spontaneous chemical side-reactions between SN and Li-metal restrict the extensive applications of such electrolytes in next-generation advanced Li-metal batteries. Herein, we report a novel SN-based electrolyte SN–DLi–FEC which combines the dual-salt (lithium bis(trifluoromethane sulfonimide) (LiTFSI) and lithium difluoro(oxalato)borate (LiODFB)) and the fluoroethylene carbonate (FEC) additive. Compared with other SN-based electrolytes such as SN–SLi–FEC (single salt combined with FEC), SN–DLi–FEC can form a more stable and durable organic–inorganic composite SEI film rich in the B–F bond and LiF on the surface of the Li-metal anode. As a result, interfacial compatibility of the SN-based electrolytes and the Li-metal anode can be significantly enhanced. Moreover, SN–DLi–FEC shows high oxidation resistance, high ionic conductivity and good thermal stability. The LiCoO2 (LCO)/Li battery equipped with SN–DLi–FEC exhibits excellent electrochemical performances at room temperature (RT) and high temperature, and high thermal safety. The novel SN-based electrolyte prepared in this work could be a promising candidate providing better reliability and safety for the development of Li-metal batteries.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2024
·Vol. 14
·期 3
·258
·
IF 2.4
Yanjie Huang,Kanghua Chang,Jie Yao,Xueyong Guo,Chen Shen,Shi Yan
To enhance both the mechanical properties of hydroxyl-terminated polybutadiene (HTPB) binder and the combustion efficiency of aluminized propellants, 2,2,3,3,4,4,5,5-octafluoro-1,6-hexanediol (OFHD) was employed as a chain extender to impart mechanical regulation to the HTPB binder. Mechanical testing showed that the mechanical properties of fluoride-modified HTPB polyurethane (FPU) were significantly improved: the peak tensile strength of the optimized samples reached 1.99 MPa, and the elongation at break attained 486%. The structural characterization of the FPUs was conducted using Fourier transform infrared (FTIR) spectroscopy. Thermogravimetry-mass spectrometer (TG-MS) analysis revealed that the initial thermal decomposition temperature of the FPU shifted from 170 °C to 162 °C, accompanied by the release of fluorine-containing fragments during decomposition. Analysis of the combustion residue indicated that the addition of OFHD can reduce the agglomeration of aluminum (Al) powder in aluminized propellants. Dynamic pressure characteristics results showed an augmented pressurization rate under argon and oxygen atmospheres, increased by 18.67% and 37.29%, respectively. Heat release tests indicated that the aluminized propellants with the addition of OFHD had a higher combustion heat, being increased by 6.57%. The binder system is expected to be applied in aluminized propellants to improve the mechanical properties and combustion efficiency of Al powder.
研究领域:
推进剂化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Yinghui Hu,Dongyu Hao,Bowen Tao,Fang Wang,Dakang Wang,Ruiqing Fan,Debin Xia,Ping Wang,Yulin Yang,Aimin Pang,Kaifeng Lin
In this study, three fluoro-containing ferrocene compounds (Fc-Fx) with different fluorine and Fc contents were prepared and then be coated on the surface of nanoaluminum (nAl) to increase the combustion performance of nAl and the anti-migration performance of Fc. By removing the aluminium oxide (Al 2 O 3 ) shell and instead constructing a new Fc-Fx shell with a thickness of 5–30 nm on the surface of nAl, the obtained nAl@Fc-Fx nanocomposites showed enhanced performances in i) anti-migration and ii) combustion performances owing to the Al-F interaction and the intimate contact between nAl and Fc-Fx. Among all three nAl@Fc-Fx nanocomposites, nAl@Fc-F2 with the longest fluorine chain could shorten the ignition delay time from 1.83 s to 1.03 s and nAl@Fc-F3 with highest Fc content could decrease the decomposition temperature of ammonium perchlorate to 328 °C. When the nAl@Fc-Fx nanocomposites were applied in the propellants, a shorter migration length (0.1–0.4 cm) was achieved as compared with the physically mixing nAl/Fc compound (3.0 cm), which was beneficial to enhancing their burning performance. This work demonstrated that nAl@Fc-Fx nanocomposites had great potential to be applied in solid rocket propellants.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
CRYSTENGCOMM
·
2018
·Vol. 20
·期 39
·5964-5968
·
IF 3.304
Bang-Chang Zhu,Wei-Hui Fang,Perumal Emayavaramban,Lei Zhang,Jian Zhang
We herein report the synthesis and structures of two salicylate-stabilized polyoxo-titanium clusters (PTCs) with and without fluorine, namely, H2[Ti13(μ3-O)7(μ2-O)4(Sal-F)9(OiPr)14] (PTC-95, H2Sal-F = 5-fluorosalicylic acid) and H2[Ti14(μ3-O)8(μ2-O)4(Sal)8(OiPr)18]·HOiPr (PTC-96, H2Sal = salicylic acid). Structural analyses indicated that PTC-95 is a fairly compact structure made up of a quadrangular prism with an appended linear Ti3 cluster and two additional Ti atoms. PTC-96 possesses an arch bridge-shaped structure linked by two Ti4(μ3-O)2 and two Ti3(μ3-O) clusters. Apart from the intrinsic structural features, their diverse photocurrent response properties and photocatalytic activities towards dye degradation were also demonstrated.
研究领域:
无机化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
LIQUID CRYSTALS
·
2016
·
IF 2.244
Dingqian Shi,Kun Hu,Pei Chen,Aiai Gao,Weisong Du,Ran Chen,Xinbing Chen,Zhongwei An
Fluorine is widely used as a lateral substituent to modify the physical properties of liquid crystals. Here, laterally monofluorinated compounds, 2-(4ʹ-alkoxy-2-fluorobiphenyl-4-yl)-benzoxazole derivatives (nPPF(2)Bx) bearing different substituents (H, CH3, NO2, coded as nPPF(2)BH, nPPF(2)BM and nPPF(2)BN, respectively) at 5-position, were synthesised and characterised. It is interesting to note that these only display enantiotropic nematic mesophases with mesophase ranges of 12–28°C and 13–45°C on heating and cooling for nPPF(2)BH, 46–97°C and 62–120°C for nPPF(2)BM and 82–108°C and 87–113°C for nPPF(2)BN, which are very different from the corresponding monofluorine-substituted analogue (compounds I) with enantiotropic smectic or smectic/nematic mesophases. The enhanced nematic mesophase is attributed to the reduced π–π interaction/conjugation resulting from the twisted structure of the molecule caused by the introduction of a fluorine atom into the inter-ring of the biphenyl unit. These results suggest that modification of the monofluorine substituent position is an effective method to improve the nematic mesophase in benzoxazole-liquid crystals.
研究领域:
材料科学
·
有机化学
✓ 已验证
DOI
高影响因子
MOLECULAR CRYSTALS AND LIQUID CRYSTALS
·
2020
·
IF 0.512
Gege Jin,Yongmin Guo,Limin Wu,Yi Li,Baozong Li,Yonggang Yang
Three series of meta-perfluoroalkylphenol esters are synthesized. Both SmA and SmC phases are identified. Their clearing points increase with increasing the perfluorocarbon chain length, while decrease with increasing the alkoxy chain length. Comparison of the 3-tridecafluorohexylbenzoates and 3-tridecafluorohexylphenol esters, the 3-tridecafluorohexylbenzoates show higher clearing points, indicating that the direction of the ester bond plays an important role in the thermostability of the liquid crystalline phases. Moreover, it was proposed that the compounds with short and long alkoxy chains packed into different structures.
研究领域:
材料化学
·
分子结构研究
✓ 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）