JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2020
·
IF 2.369
Haigang Liu,Bing Jia,Weizhen Sun,Shihua Dong
Liquid–liquid equilibrium (LLE) data for water + 2-methyl-3-buten-2-ol + (isopropyl ether or 4-methylpentan-2-ol or p-xylene or ethyl acetate) ternary systems was measured at 308.2 K under 101.3 kPa. Distribution coefficients and separation factors were obtained and applied to evaluate the extraction capacity of selected solvents. Furthermore, the experimental LLE data were successfully correlated by the nonrandom two-liquid (NRTL) and universal quasi-chemical (UNIQUAC) models, which showed a root-mean-square deviation (RMSD) of less than 0.78% for all systems.
研究领域:
化学工程
·
热力学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2022
·Vol. 24
·期 20
·12550-12562
·
IF 3.945
Xue Fu,Xiaochen Tang,Tingting Chen,Yingjie Xu,Xiang Luo,Yueqing Lu,Xuming Wang,Dandan Qin,Lin Zhang
The interactions between azole-anion-based ionic liquids (AILs) and 2-methyl-3-butyn-2-ol (MBY) play an important role in AIL-promoted carboxylative cyclization of MBY with CO2. To better understand the interactions between AILs ([P66614][Im], [P66614][4-MeIm], and [P66614][4-BrIm]) and MBY, a detailed investigation from the experimental perspective has been carried out in this study. The results show that the derivative of viscosity (η) with the mole fraction of AIL (xAIL) of AIL + MBY mixtures appears to have the maximum value when xAIL ≈ 0.3, while 1H NMR chemical shifts of P-CH2 of [P66614]+ reach the minimum value at xAIL ≈ 0.3, indicating that [P66614]+ of AILs tend to self-aggregate. The interaction parameters (gji–gii) of the systems obtained from η by the Eyring-UNIQUAC equation are positive, and the difference between the bulk and local composition (xi–xii) is always negative, indicating that AILs can interact with MBY. Moreover, excess molar volumes and isentropic compressibility deviations are all negative deviations and become more negative as the temperature increases, reaching a minimum value at xAIL ≈ 0.30, indicating that azole-based anions can form H-bonds with MBY, and MBY molecules tend to enter the aggregates formed by AILs. Consequently, the cage effect is proposed to describe the interactions between AILs and MBY: MBY first enters the cage formed by the aggregation of [P66614]+, and then forms H-bonds with azole-based anions. Finally, the sizes of the particles of the [P66614][Im] + MBY mixture from dynamic light scattering increase first and then decrease with xAIL, with the maximum of 122 nm at xAIL ≈ 0.25, which confirms the rationality of the cage effect.
研究领域:
化学
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材料科学
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产品关联
DOI
PubMed
高影响因子
Nature Communications
·
2022
·Vol. 13
·期 1
·1-10
·
IF 17.694
Yang Yang,Zhu Xiaojuan,Wang Lili,Lang Junyu,Yao Guohua,Qin Tian,Ren Zhouhong,Chen Liwei,Liu Xi,Li Wei,Wan Ying
Pd catalysts are widely used in alkynol semi-hydrogenation. However, due to the existence of scaling relationships of adsorption energies between the key adsorbed species, the increase in conversion is frequently accompanied by side reactions, thereby reducing the selectivity to alkenols. We report that the simultaneous increase in alkenol selectivity and alkynol conversion is achieved by manipulating interstitial atoms including B, P, C, S and N in Pd catalysts. A negative linear relationship is observed between the activation entropies of 2-methyl-3-butyn-2-ol and 2-methyl-3-buten-2-ol which is highly related to the filling of d -orbital of Pd catalysts by the modification of p -block elements. A catalyst co-modified by B and C atoms has the maximum d charge of Pd that achieves a 17-fold increase in the turn-over frequency values compared to the Lindlar catalysts in the semi-hydrogenation of 2-methyl-3-butyn-2-ol. When the conversion is close to 100%, the selectivity can be as high as 95%.
研究领域:
催化
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化学工程
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材料科学
✓ 已验证
DOI
高影响因子
MOLECULES
·
2013
·Vol. 18
·期 4
·4158-4169
·
IF 2.428
Luhui Ren,Xue Du,Mengnan Hu,Chaoqun Yan,Taigang Liang,Qingshan Li
An asymmetric synthesis of a series of novel 4-methyl-(3'S,4'S)-cis-khellactone derivatives3a–ois reported for the first time. Their structures were confirmed by1H-NMR,13C-NMR and MS. Their cytotoxic activity was evaluated by the MTT assay against three selected human cancer cell lines: HEPG-2 (human liver carcinoma), SGC-7901 (human gastric carcinoma), LS174T (human colon carcinoma). Some compounds showed high inhibitory activity against these human cancer cell lines. Among them, compound3aexhibited strong cytotoxicity, with IC50values ranging from 8.51 to 29.65 μM. The results showed that 4-methyl-cis-khellactone derivatives withS,Sconfiguration could be a potential antitumor agents.Keywords:4-methyl-(3'S,4'S)-cis-khellactone derivatives;asymmetric synthesis;antitumor activity
研究领域:
药物化学
·
肿瘤学
·
有机合成化学
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DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
·
2020
·Vol. 96
·期 1
·48-63
·
IF 2.75
Ling Li,Peng Hong,Anton A Kiss,Hui Tian,Xiaoda Wang,Ting Qiu
BACKGROUND 3-Methyl-3-penten-2-one (3M3P) is an indispensable raw material used for the synthesis of OTNE (octahydrotetramethyl acetophenone), a synthetic ketone fragrance known by commercial trade names, such as Iso E Super® , which is one of the most important ingredients in perfumes. This work is the first to unravel the reaction route and kinetics for the synthesis of 3M3P via the cross-aldol condensation of acetaldehyde with butanone, catalyzed by the heterogeneous acidic ion exchange resin (NKC-9). RESULTS An effective method was developed to evaluate this complex reaction system: the reaction routes were determined experimentally from the product structures detected by Gas Chromatography Mass Spectrometry (GC-MS), and the significance of side reactions were evaluated by the Yoneda group contribution method. The major side reactions are the self-condensation of acetaldehyde (significant even under optimized reaction conditions) and the cross-aldol condensation of acetaldehyde with 3M3P (which could be effectively suppressed at high butanone-acetaldehyde molar ratio). The reaction kinetics was investigated at temperatures of 60–90 °C, catalyst mass fraction of 5 to 15%, and molar ratio of 5–20. At optimized reaction conditions, the yield of 3M3P was up to 90.85%, which is 2.4 times higher than that for the classic homogeneous catalysts (yield <38%). CONCLUSION Acidic ion exchange resin NKC-9 is a high-selective green catalyst for the cross-aldol condensation of acetaldehyde with butanone. Integrating experimental determination and thermomechanical analysis is an effective method to unravel the main reaction routes for a complex system. © 2020 Society of Chemical Industry (SCI)
研究领域:
有机化学
·
催化化学
·
香料化学
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产品关联
DOI
高影响因子
JOURNAL OF ORGANOMETALLIC CHEMISTRY
·
2016
·
IF 2.336
Kun Liu,Kai-Kai Liu,Mu-Jeng Cheng,Ming-Han Han
A combined experimental and theoretical study was conducted to investigate the isomerization of 2-methyl-3-butenenitrile (2M3BN) to 3-pentenenitrile (3PN) and to 2-methyl-2-butenenitrile (2M2BN) catalyzed by nickel diphosphine complexes. Ni(1,4-bis(diphenylphosphino)butane) (dppb) was identified as the most reactive catalyst among the complexes that we examined experimentally. Quantum mechanics (density functional theory) was then used to study the two isomerization mechanisms catalyzed by this complex. We find that for the 2M3BN → 3PN isomerization, the reaction is initiated with C CN bond cleavage, followed by an allyl direct rotation and C CN bond reformation. For the 2M3BN → 2M2BN isomerization, the most energetically favorable pathway begins with C H bond activation, followed by a π-σ-σ-π allyl rearrangement and C H bond reformation. Our proposed mechanism for the 2M3BN → 2M2BN isomerization is slightly different (yet energetically more favorable) than that described in previous studies, where it has been suggested that 2M2BN is obtained through a π-σ-σ allyl rearrangement rather than a π-σ-σ-π type rearrangement. Additionally, we investigated the effect of Lewis acids in the 2M3BN → 3PN isomerization, which has been shown in most experiments to attenuate the reaction. Notably, our calculations indicated that ZnCl 2 , which is used as a model Lewis acid, actually reduces the barriers for all elementary steps. However, the effective kinetic barrier for the isomerization increases from 23.7 (without ZnCl 2 ) to 24.0 kcal/mol because of the formation of a very stable Ni(π-allyl) (CN ZnCl 2 ) intermediate, causing a decrease in the reaction rate. This theoretical result was further confirmed by our own experiments.
研究领域:
有机化学
·
理论化学
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DOI
高影响因子
MATERIALS SCIENCE FORUM
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2020
·
IF 0
Hong Qian Dai,Yuan Lu,Zhi Hin Ou,Min Xu
Fe3O4-APTES-CS2 was prepared by modification of Fe3O4 with 3-aminopropyltriethoxysilane (APTES) and carbon disulfide (CS2). Lipase was covalently bonded to Fe3O4-APTES-CS2 to obtain the immobilized lipase Fe3O4-APTES-CS2-lipase. The textural characteristic of Fe3O4-APTES-CS2-lipase was assessed by scanning electron microscopy. The optimal immobilization conditions were 2.5 mg/mL lipase, pH 7.0, 35 °C, 3 h. The loading amount of lipase was 119.0 mg/g carrier. The immobilization efficiency reached 57%. (R)-(+)-N-acetyl-1-methyl-3-amphetamine was synthesized by Fe3O4-APTES-CS2-Li- pase. The conversion, enantiomeric excess of (R)-(+)-N-acetyl-1-methyl-3-amphet-a- mine and E value reached 36.8%, 98.5% and 132, respectivel.
研究领域:
化学
·
生物化学
·
材料科学
·
催化
✓ 已验证
DOI
JOURNAL OF APPLIED POLYMER SCIENCE
·
2011
·Vol. 124
·期 6
·4915-4919
·
IF 1.24
Nianjun Kang,Zhongjie Du,Hangquan Li,Chen Zhang
Polymethyl(3-glycidyloxypropyl)siloxane (PMGS) was synthesized as a flame-retardant additive, which were cocured with diglycidyl ether of bisphenol-A (DGEBA) using 4,4′-diaminodiphenylsulfone as a curing agent. The structure of PMGS was confirmed through Fourier transform infrared and 1 H-NMR spectra. The cured products were characterized with dynamic mechanical thermal analysis, thermogravimetric analysis, and oxygen index analyzer. With PMGS incorporated, the cured epoxy resin showed better thermal stability, higher limited oxygen index, and higher char yield. At moderate loading of PMGS, the storage modulus and glass transition temperature of the cured epoxy resin based on neat DGEBA were obviously improved. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
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
ADVANCED FUNCTIONAL MATERIALS
·
2024
·
IF 18.5
Wenxin Wang,Ruidong Yang,Qiqi Mao,Xu Mu,Hongjie Yu,Kai Deng,Jianguo Wang,Liang Wang,Hongjing Wang
The utilization of green hydrogen sources in H 2 O for alkynols electrocatalytic semihydrogenation reaction (ESHR) at ambient temperature provides a promising pathway toward the sustainable conversion of alkynols. However, it is still a great challenge to construct specific interfacial structure to adjust the electronic structure of Pd for the purpose of altering the strong adsorption of Pd with active hydrogen to enhance the production of alkenols. Here, the atomically dispersed GaO x -PdMo bimetallene nanoribbons (GaO x -PdMo BNRs) via oxygen bridging Ga atoms is designed to the surface of PdMo BNRs for 2-methyl-3-butyn-2-ol (MBY) ESHR to the synthesis of 2-methyl-3-buten-2-ol (MBE). The GaO x -PdMo BNRs achieve the excellent MBE selectivity (≈97.4%), Faraday efficiency (≈96.1%), and maintain long-term stability. Density functional theory demonstrates that the top electron-enriched Ga atoms and the bottom electron-deficient Pd atoms construct a “pyramidal” interface via the oxygen bridge. The unique surface can effectively activate H 2 O and weaken interaction between catalyst and MBE, thus promoting MBE generation. Moreover, the electron bridge effect between Ga-O-PdMo can induce p-d orbital hybridization to achieve lower the d -band center of surface Pd thus modulating the reactants adsorption. This work provides a strategy to improve ESHR performance by electron bridge effect to modulate interfacial electron distribution.
研究领域:
材料科学
·
催化化学
·
理论计算
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2023
·
IF 2.6
Cheng Xie,Fuyi Sun,Xunke Zhao,Cui Wu,Yuanyuan Che
A transient hot-wire method was used in this work to measure the thermal conductivities of methyl 2-methyl-3-nitrobenzoate (MMN) + acetonitrile, N-bromosuccinimide (NBS) + acetonitrile, and MMN + NBS + acetonitrile in the temperature range of T = (300–340) K. For binary systems, measurements were made for the mass fractions of MMN (ω1) range from 0 to 0.45 and the mass fractions of NBS (ω2) range from 0 to 0.30. For the ternary system, measurements were carried out with the ω1 + ω2 range from 0 to 0.45. The expanded uncertainties of the experimental data were estimated to be 2%, while the confidence level was 0.95 (k = 2). The experimental data were correlated as a function of the mass fraction and temperature using a linear thermal conductivity model. The maximum absolute relative deviation between the experimental values and the calculated results from the fitting model were 0.60, 0.16, and 1.30%.
研究领域:
物理化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Ao Zhuang,Yongjun Bian,Jianwei Zhou,Suna Fan,Huili Shao,Xuechao Hu,Bo Zhu,Yaopeng Zhang
Various attractive materials are being used in bioelectronics recently. In this paper, hydroxymethyl-3,4-ethylenedioxythiophene (EDOT-OH) has been in situ integrated and polymerized on the surface of the regenerated silk fibroin (RSF) film to construct a biocompatible electrode. In order to improve the efficiency of in situ polymerization, sodium dodecyl sulfate (SDS) was adopted as surfactant to construct a well-organized and stable poly(hydroxymethyl-3,4-ethylenedioxythiophene) (PEDOT-OH) coating, whereas ammonium persulfate was used as oxidant. The effects of dosages of surfactant and oxidant, initial pH value, and monomer concentration on the polymerization were studied. Under the optimal conditions, the RSF/PEDOT-OH film exhibited a square resistance of 3.28 × 105 Ω corresponding to a conductance of 6.1 × 10–3 S/cm. Scanning electron microscope images indicated that PEDOT-OH was deposited uniformly on the surface of the RSF film with SDS. Furthermore, Fourier transform infrared spectroscopy confirmed that interactions existed between the peptide linkages of silk fibroin (SF) macromolecules and PEDOT-OH. The RSF/PEDOT-OH film displayed favorable electrochemical stability, biocompatibility, and fastness. This study provides a feasible method to endow conductivity to RSF materials in various forms. In addition, the conductive layer and biocompatible silk substrate make the RSF/PEDOT-OH biomaterial highly suitable for potential applications in bioelectric devices, sensors, and tissue engineering.
研究领域:
生物工程
·
材料科学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2016
·Vol. 21
·期 8
·1071
·
IF 2.465
Liang Cai,Li-Fang Wang,Jun-Ping Pan,Xiang-Nan Mi,Zheng Zhang,Hai-Ju Geng,Jia-Hui Wang,Song-Hui Hu,Wei Zhang,Qin Gao,Wu-Tian Wu,Huan-Min Luo
This study investigated the neuroprotective effects of methyl 3,4-dihydroxybenzoate (MDHB) againstt-butyl hydroperoxide (TBHP) induced oxidative damage in SH-SY5Y (human neuroblastoma cells) and the underlying mechanisms. SH-SY5Y were cultured in DMEM + 10% FBS for 24 h and pretreated with different concentrations of MDHB orN-acetyl-l-cysteine (NAC) for 4 h prior to the addition of 40 μM TBHP for 24 h. Cell viability was analyzed using the methylthiazolyltetrazolium (MTT) and lactate dehydrogenase (LDH) assays. An annexin V-FITC assay was used to detect cell apoptosis rates. The 2′,7′-dichlorofluorescin diacetate (DCFH-DA) assay was used to determine intracellular ROS levels. The activities of antioxidative enzymes (GSH-Px and SOD) were measured using commercially available kits. The oxidative DNA damage marker 8-OHdG was detected using ELISA. Western blotting was used to determine the expression of Bcl-2, Bax, caspase 3, p-Akt and Akt proteins in treated SH-SY5Y cells. Our results showed that MDHB is an effective neuroprotective compound that can mitigate oxidative stress and inhibit apoptosis in SH-SY5Y cells.Keywords:methyl 3,4-dihydroxybenzoate;oxidative stress;apoptosis;neuroprotection;nuclear factor erythroid 2-related factor 2
研究领域:
神经科学
·
药理学
·
细胞生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）