TETRAHEDRON
·
2024
·
IF 2.1
Nan Wang,Yuanyuan Huang,Mengke Wang,Weichun Huang,You Zi
Herein, a new approach for the synthesis of ( Z )- N -alkenyl-2-pyridones from 2-pyridones and propiolates using phosphine catalysis under mild conditions is reported. This dual Z -diastereoselective and N -selective reaction demonstrates excellent selectivity, yielding sole ( Z )- N -alkenyl-2-pyridones. Furthermore, scale-up studies confirm its practical applicability, with consistent efficiencies observed.
✓ 已验证
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2011
·
IF 2.546
Lei Li,Xiaoying Du,Jianping Deng,Wantai Yang
Optically active macroporous poly( N -isopropylacrylamide) (PNIPAM) hydrogels were synthesized via free radical copolymerization of NIPAM, helical macromonomer, and cross-linker N , N ′-methylenebisacrylamide. The helical macromonomer not only contained catechol groups but also vinyl groups in side chains. Polyethylene glycols were used as pore-forming agent to give rise to macroporous structures in the optically active hydrogels. The hydrogels were characterized by FT-IR, SEM, DSC , swelling ratio and circular dichroism spectra analyses and exhibited the expected optical activity and macroporous architectures. The chiral resolution tests demonstrated the preferential adsorption of the hydrogels towards d -tryptophan and d -phenylalanine in the corresponding two amino acid enantiomers .
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Guanwei Zhao,Wei Ma,Hongyu Pang,Ligang Zhang,Yuzheng Wang,Xiaoxue Ren,Kuo Liu,Hongling Yang,Yongchun Liu
Low-temperature catalytic oxidation is a prevalent technology for toluene removal due to its reduced energy demand. In this study, N,N-dimethylformamide (DMF) was used to control the particle size of active metals. The activity tests revealed that Pt nanoparticles with a particle size of 5–15 nm exhibited higher activity for toluene oxidation and maintained good hydrothermal stability on the SBA-15 support. The results suggest that despite the increase of Pt particle size by using DMF, the proportion of Pt 0 and the oxygen activation ability were both increased. The reaction pathway of the toluene oxidation over Pt/SBA-15 was examined in depth by in situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS), proton transfer reaction time-of-flight mass spectrometry (PTR-TOF-MS) and cluster analysis, revealing that the benzyl alcohol, benzaldehyde, and benzoic acid species were primary intermediate products. The benzaldehyde on the larger Pt nanoparticles is conducive to decomposing and generating CO 2 for complete mineralization, promoting the activity of toluene oxidation. This work highlights the significance of DMF-induced size effects in the development of low-temperature oxidation catalysts and understanding of reaction mechanism, guiding the design of new efficient toluene oxidation catalysts.
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Jingru Zhang,Guangxin Yang,Junyu Zhang,Cong Kong,Jun Wang
The misuse of sulfonamide and fluoroquinolone antibiotics leads to pollution of the water environment, necessitating the development of cost-effective and efficient degradation methods. This article presents a one-step hydrothermal method (200℃, 8 h) for the preparation of Fe-N-co-doped biochar/carbon quantum dots (Fe/N/BC/CQDs) as a photocatalytic material. The Fe/N/BC/CQDs was employed for the activation of H 2 O and O 2 , facilitating the degradation of sulfonamide and fluoroquinolone antibiotics, with superoxide radicals, photo-generated holes, hydroxyl radicals, and singlet oxygen dominated the photodegradation process. Under 1 h dark and 8 h natural light conditions, the degradation efficiency of norfloxacin, sulfathiazole, sulfamethoxazole, sulfamonomethoxine, sulfadoxin, sulfamethazine (10 mg/L) by Fe/N/BC/CQDs ranged from 74.21 % to 89.23 %. The potential degradation pathways of sulfonamide and fluoroquinolone antibiotics were proposed based on ultrahigh-performance liquid chromatography tandem high-resolution mass spectrometry analysis of the intermediates. The Fe-N-doped biochar’s hierarchical pore structure enhances synergistic adsorption-catalysis effects, while the incorporated carbon quantum dots (CQDs) broaden solar spectrum utilization, effectively overcoming the high-intensity light dependency common to conventional photocatalysts. Efficient charge separation was achieved through the formation of a p-n heterojunction between Fe-N-co-doped biochar and CQDs. Additionally, the applicability of Fe/N/BC/CQDs in real water systems was confirmed, providing valuable insights for the construction of p-n heterojunction structures to degrade organic pollutants in water.
✓ 已验证
DOI
高影响因子
ChemSusChem
·
2015
·Vol. 8
·期 12
·2066-2072
·
IF 7.657
Yehong Wang,Jian Zhang,Jing Liu,Chaofeng Zhang,Zhixin Zhang,Jie Xu,Shutao Xu,Fangjun Wang,Feng Wang
Graphical CO 2 -mediated reactions: CO 2 -mediated metathesis reactions between amines and DMF to synthesize formamides are described. The N -formylation of amines to formamides is achieved by activating amines, not DMF, via a C N and N H bond metathesis reaction. Using this method, primary, secondary, aromatic, and heterocyclic amines as well as diamines can be obtained with good to excellent formamide yields. Herein, we report CO 2 -mediated metathesis reactions between amines and DMF to synthesize formamides. More than 20 amines, including primary, secondary, aromatic, and heterocyclic amines, diamines, and amino acids, are converted to the corresponding formamides with good-to-excellent conversions and selectivities under mild conditions. This strategy employs CO 2 as a mediator to activate the amine under metal-free conditions. The experimental data and in situ NMR and attenuated total reflectance IR spectroscopy measurements support the formation of the N -carbamic acid as an intermediate through the weak acid–base interaction between CO 2 and the amine. The metathesis reaction is driven by the formation of a stable carbamate, and a reaction mechanism is proposed.
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2021
·
IF 7.92
Jianguo Liu,Shanshan Lin,Jiangming Sun,Longlong Ma
Transition metal-catalyzed semi-hydrogenation of alkynes has become one of the most popular methods for alkene synthesis. Specifically, the noble metal Pd, Rh, and Ru-based heterogeneous catalysts have been widely studied and utilized in both academia and industry. But the supported noble metal catalysts are generally suffering from leaching or aggregation during harsh reaction conditions, which resulting low catalytic reactivity and stability. Herein, we reported the facile synthesis of nitrogen doped graphene encapsulated Pd catalyst and its application in the chemo-selective semi-hydrogenation of alkynes. The graphene layer served as “bulletproof” over the active Pd Nano metal species, which was confirmed by X-ray and TEM analysis, enhanced the catalytic stability during the reaction conditions. The optimized prepared Pd@N/C catalyst showed excellent efficiency in semi-hydrogenation of phenylacetylene and other types of alkynes with un-functionalized or functionalized substituents, including the hydrogenation sensitive functional groups (NO 2 , ester, and halogen).
✓ 已验证
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2015
·Vol. 293
·期 9
·2617-2624
·
IF 1.865
Yan Zhihu,Dai Caili,Zhao Mingwei,Zhao Guang,Li Yuyang,Wu Xuepeng,Liu Yifei,Du Mingyong
Dual-stimulated wormlike micelles regulated by pH and temperature in a surface active ionic liquid system comprising of a cationic surfactant ( N -cetyl- N -methylpyrrolidinium bromide (C 16 MDB)) and an aromatic dibasic acid (pyrocatechol) were investigated. Such a system can be reversibly switched between liquid-like and gel-like states on adjusting the solution pH value. The rheology, light scattering techniques and cryogenic-transmission electron microscopy (cryo-TEM) results show the growth of spherical micelles into long and entangled wormlike micelles was responsible for the changes in flow properties such as high viscosity, shear-thinning behaviour and Maxwell-type dynamic rheology. The nuclear magnetic resonance results reveal the binding capacity of pyrocatechol to C 16 MDB is proposed as the key factor of the unusual rheological and micellar responses of this pH-stimulated system. In addition, with the increase of temperature, molecular motion of surfactant molecules becomes more active, which endow the property of thermo-stimulated to the surface active ionic liquid system.
✓ 已验证
DOI
高影响因子
PREPARATIVE BIOCHEMISTRY & BIOTECHNOLOGY
·
2017
·
IF 1.361
Xiaoyan Li,Chen Qi,Peilian Wei,Lei Huang,Jin Cai,Zhinan Xu
Uridine 5′-diphosphate N-acetylglucosamine (UDP-GlcNAc) is a natural UDP-monosaccharide donor for bacterial glycosyltransferases, while uridine 5′-diphosphate N-trifluoacetyl glucosamine (UDP-GlcNTFA) is its synthetic mimic. The chemoenzymatic synthesis of UDP-GlcNAc and UDP-GlcNTFA was attempted by three recombinant enzymes. Recombinant N-acetylhexosamine 1-kinase was used to produce GlcNAc/GlcNTFA-1-phosphate from GlcNAc/GlcNTFA. N-acetylglucosamine-1-phosphate uridyltransferase from Escherichia coli K12 MG1655 was used to produce UDP-GlcNAc/GlcNTFA from GlcNAc/GlcNTFA-1-phosphate. Inorganic pyrophosphatase from E. coli K12 MG1655 was used to hydrolyze pyrophosphate to accelerate the reaction. The above enzymes were expressed in E. coli BL21 (DE3) and purified, respectively, and finally mixed in one-pot bioreactor. The effects of reaction conditions on the production of UDP-GlcNAc and UDP-GlcNTFA were characterized. To avoid the substrate inhibition effect on the production of UDP-GlcNAc and UDP-GlcNTFA, the reaction was performed with fed batch of substrate. Under the optimized conditions, high production of UDP-GlcNAc (59.51 g/L) and UDP-GlcNTFA (46.54 g/L) were achieved in this three-enzyme one-pot system. The present work is promising to develop an efficient scalable process for the supply of UDP-monosaccharide donors for oligosaccharide synthesis.
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2017
·
IF 1.753
Yun Bai,Po Yang,Tao Wang,Yi Gu
This work aims at probing the formation of hydrogen bonds in the blends of polybenzoxazines and additional hydrogen-bond donor moieties-containing compounds. Based on experimental study and computer simulations, we found that the dominant hydrogen bonds of p -cresol-aniline-based dimer ( p C-a-D) and polybenzoxazines (P p C-a) were OH⋯N while N,N ′-(pyridine-2,6-diyl)diacetamide (DAA) was NH⋯O C hydrogen bond. After blending p C-a-D or P p C-a with DAA, additional hydrogen bonds formed, i.e. , OH⋯O C and OH⋯ NH. Moreover, the total quantity of hydrogen bonds of the blends increased. These results suggested that hydrogen bonds formed between polybenzoxazines and the additional hydrogen-bond donor moieties-containing polymers or compounds, and furthermore would be desirable to foster the promoted performance. This novel insight about polybenzoxazine blends is anticipated to help researchers explore more blends of polybenzoxazines with excellent properties.
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2017
·
IF 4.798
Chunguang Chen,Liangyu Li,Junming Su,Congcong Zhang,Xiang Chen,Tao Huang,Aishui Yu
Although dimethylsulfoxide (DMSO) solvent has been widely researched in rechargeable lithium-oxygen (Li-O 2 ) batteries , high polarization voltage and low rate capability limited its application. In this work, we reported a DMSO-based electrolyte system by adding N, N-dimethylacetamide (DMA) to adjust its physical and electrochemical properties. The ionic conductivity , viscosity, oxygen solubility and diffusion coefficient of the mixed electrolytes as well as their electrochemical performance in Li-O 2 batteries are researched. The electrochemical tests show that the optimized DMSO/DMA volume ratio is 30 to 70 based on the rate performance and polarization voltage of the cell. Compared with that of the pure DMSO-based electrolyte, the cell with the mixed electrolyte shows improved rate capability and reduced charge-discharge over-potential. When increasing current density from 0.2 to 0.5 mA cm −2 , the capability retention improves from 32% to 59%. Meanwhile, the charge-discharge voltage gap drops from 1.4V to 0.9V at a current density of 0.2 mA cm −2 . The improved electrochemical performance could be attributed to low viscosity, high oxygen solubility and diffusion coefficient as well as the low charge-transfer resistance with the mixed electrolyte.
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2017
·
IF 1.179
Lala Rukh Sidra,Nafeesa Mushtaq,Guofei Chen,Xingzhong Fang
A series of poly(N-arylene benzimidazole ether imide) copolymers PEIBIs were prepared from 1H,3′H-5,5′-bis-benzimidazole, bisphenol-A and 4,4′-bis(4-fluorophthalimido)diphenyl ether by nucleophilic displacement polymerization. The resulting copolymers PEIBI(10–90) demonstrated moderate to good solubility in polar aprotic solvents and high glass transition temperatures (Tgs) of 228–336°C, good thermal stability with 10% weight loss temperatures in the range of 503–548°C. All copolymer films showed good mechanical properties with tensile strengths of 101–130 MPa, tensile moduli of 3.3–4.0 GPa, elongations at break of 5–7%, and also presented low water uptake (0.15–0.34%). The wide-angle X-ray diffraction results revealed the amorphous nature of copolymers. The copolymer PEIBI-80 showed good balance in solubility, thermal and mechanical properties.
✓ 已验证
DOI
高影响因子
JOURNAL OF CHROMATOGRAPHIC SCIENCE
·
2017
·Vol. 55
·期 6
·662-668
·
IF 0.984
Ma Xiaowei,Feng Fan,Yang Yang,Dang Xueping,Huang Jianlin,Chen Huaixia
Fe3O4@MIL-100 (MIL, Material Institut Lavoisier) core–shell magnetic microspheres were prepared and applied as the sorbent for the magnetic solid phase extraction (MSPE) of N,N-diethyl-m-toluamide (DEET) in baby toilet water for the first time. The synthesized magnetic metal–organic frameworks were characterized by transmission electron microscope, infrared spectroscopy and thermogravimetric analysis. The functionalized magnetic microparticles showed excellent dispersibility in aqueous solution. The MSPE conditions were investigated in detail. Under the optimized conditions, an MSPE–high performance liquid chromatography method for the determination of DEET was developed. The method was linear in the concentration range from 5 to 500 μg L−1 for DEET in baby toilet water and good linearity (r2 > 0.9998) was obtained for the calibration curve. The limit of detection was 1.5 μg L−1. Both the intra-day and inter-day precisions (relative standard deviations) were <3%.
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）