Catalysts
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2023
·Vol. 13
·期 5
·915
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IF 3.9
Xiaofeng Yu,Chunjie Shi,Yueling Cheng,Yejing Zhu,Renyuan Song,Shengfei Hu
Methyl benzoate (MB) compounds are prepared by reacting various benzoic acids with methanol using an acidic catalyst. In this study, the solid acids of zirconium metal solids fixed with various substances were studied. We determined that zirconium metal catalysts with fixed Ti had the best activity. The catalytic synthesis of a series of MB compounds using titanium zirconium solid acids was studied. The direct condensation of benzoic acid and methanol using a metallic Lewis acid without other auxiliary Bronsted acids is reported for the first time.Keywords:methyl benzoate;solid acid;catalysis
研究领域:
有机化学
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催化化学
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
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2020
·
IF 5.065
Xiao Feng,Tingting Chen,Yuqiao Yin,Yingjie Xu
By a comparative study of the concentration-dependent IR spectra of methyl benzoate (MB)/methanol- d 4 and MB/ n -hexane mixtures, it is found that the infrared wavenumber ( υ ˜ ) of ester group (O C O) of MB in the former system decreased exponentially with the increase of mole fraction of MB ( x 1 ), while that of the latter system decreased linearly, suggesting that H-bonding interaction plays an important role in the microstructure of MB/methanol- d 4 mixture. Therefore, to explore the microstructure and characterize the strength of H-bonding interaction of MB/methanol mixture, the excess infrared wavenumber of a group ( υ ˜ group E ) is proposed, showing that υ ˜ O − D E of methanol- d 4 presents an S shape with a minimum value at x 1 ≈ 0.4 and a maximum value at x 1 ≈ 0.8, respectively. Furthermore, the absolute value of υ ˜ O − D E (| υ ˜ O − D E |) of the former is greater than that of the latter, suggesting that H-bonding interaction in methanol- d 4 molecules is stronger than that between methanol- d 4 and MB. While both υ ˜ C = O E and υ ˜ C − O E of MB show a negative deviation with minimum values at x 1 ≈ 0.4, and | υ ˜ C = O E | is larger than | υ ˜ C − O E |, indicating that C O is directly involved in H-bonding interaction with O D, resulting in the change of υ ˜ C − O E through the electronic conjugation effect. To confirm the microstructure obtained from IR spectra, densities, speeds of sound , and viscosities of MB/methanol mixture are measured and excess properties are calculated. The results show that both excess molar volumes and isentropic compressibility deviations have a negative deviation with a minimum value at x 1 ≈ 0.4, which is good consistent with x 1 corresponding to the minimum value of υ ˜ O − D E , υ ˜ C = O E , and υ ˜ C − O E , respectively. Moreover, viscosity deviations exhibit a negative deviation with a minimum value at x 1 ≈ 0.8, which is good consistent with x 1 corresponding to the maximum value of υ ˜ O − D E .
研究领域:
物理化学
·
光谱学
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高影响因子
JOURNAL OF STORED PRODUCTS RESEARCH
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2024
·
IF 2.7
Junli Xiao,Jianbo Jin,Shanyi Chen,Jianfeng Zhang,Peijian Cao,Li-Juan Mao,Ran Li
The cigarette beetle, Lasioderma serricorne (F.), presents a significant management challenge as a stored product pest. The beetle's increasing resistance to conventional fumigants necessitates the search for alternative solutions to mitigate losses in agro-based industries. Here, we constructed a small molecule compounds library containing twenty-eight methyl benzoate-related compounds (MBCs) and evaluated their repellent and toxic effects against cigarette beetles by Y-tube olfactometer behavioral assays, free-choice box assays and fumigation assays. We found that six MBCs (methyl 3-methoxybenzoate, methyl benzoate, methyl 3-formylbenzoate, methyl 2-aminopyridine-3-carboxylate, methyl 2-aminobenzoate and methyl 4-amino-2-methoxybenzoate) act as repellents for cigarette beetles. Notably, methyl benzoate (MeBA) was effective across a broader range of concentrations (200–4000 ppm) compared to other MBCs. Four compounds (methyl 3-formylbenzoate, methyl 2-aminopyridine-3-carboxylate, methyl 2-aminobenzoate and methyl 4-amino-2-methoxybenzoate) required higher minimum concentrations (500–4000 ppm) than MeBA for repellence, while methyl 3-methoxybenzoate was effective at a concentration (10 ppm) lower than that for MeBA. Mixtures of MeBA with methyl 3-methoxybenzoate and methyl 3-formylbenzoate enhanced the repellent effect against cigarette beetles when compared to MeBA alone. Additionally, exposure to varying concentrations of MeBA, methyl 3-methoxybenzoate, methyl 3-formylbenzoate, and methyl 2-aminobenzoate resulted in 100% mortality of cigarette beetles. Our findings indicate that specific MBCs offer the potential for their use as repellents and fumigants for this problematic stored product pest.
研究领域:
昆虫学
·
害虫管理
·
农业科学
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2019
·
IF 5.107
Qianhui Mao,Qi Li,Huimin Li,Shoujun Yuan,Jibiao Zhang
This study investigated the reactivity and mechanism of paraben oxidization by chlorine dioxide. Degradation kinetics of methylparaben (MeP) and propylparaben (PrP) followed pseudo-first-order kinetics, and were studied in a pH range of 4.0–7.0 at 15 ± 1 °C. The k app values were 84.3 M −1 ·s −1 and 83.2 M −1 ·s −1 for MeP and PrP, respectively, when pH value was 5.0 and the temperature was 15 ± 1 °C. The rate constants depended on the solution pH, temperature, humic acid, and HCO 3 – concentrations. At pH values of 4–5.0, k app increased slowly, while at a pH value of 7.0, k app increased rapidly. The reaction rate constants increased with increasing temperature. Furthermore, the reaction rate was inhibited by humic acid addition, while the reaction rate increased after addition of HCO 3 – . Two main degradation products were identified by GC–MS and the reaction pathways were proposed.
研究领域:
环境科学
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化学工程
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2024
·
IF 5.3
Xin Hu,Yang Guo,Feng Xia,Shangwu Ding,Zhong Chen,Xiaohong Cui
Micellar solubilization is considered as a key factor affecting the recovery efficiency in chemically enhanced oil recovery (cEOR). However, it is poorly understood how polymers in surfactant-polymer (SP) flooding influences the micellar solubilization. Guar gum (GG) and hydroxyethyl cellulose (HEC) are two important and widely used polysaccharide polymers. In this work, the effect of GG and HEC on the solubilization of a crude oil model compound methyl benzoate (MB) in anionic sodium dodecyl sulfate (SDS) micelles and the underlying mechanism were explored at the molecular scale by NMR spectroscopy. GG and HEC slightly increased the MB solubility in SDS micelles but did not change the solubilization capacity. No correlation peak was observed to demonstrate the attractive interaction between polymer and SDS. After examination, there is weak electrostatic repulsion between HEC/GG and SDS, which made the polymer independent from SDS micelles and was unable to participate in the formation of micelles to alter micellar structure and solubilization behavior. Although the solubility of MB was slightly increased, this increase should originate from weak molecular interactions between polymers, surfactants and hydrophobic molecules, including hydrogen bonding, van der Waals forces and hydrophobic interactions, etc. In summary, without strong electrostatic attraction between polymer and surfactant, the solubilization of polymers and the solubilization of micelles proceed independently, resulting in that the solubilization capacity of SDS micelles was not improved.
研究领域:
化学工程
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石油工程
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分子生物学
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DOI
高影响因子
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