CHINESE JOURNAL OF CHEMICAL PHYSICS
·
2022
·Vol. 35
·期 2
·242-248
·
IF 1.09
Min Yan-jun,Yuan Wen-peng,Yang Dong-yuan,Dai Dong-xu,Yu Sheng-rui,Wu Guo-rong,Yang Xue-ming
The S 1 state decay dynamics of 2-hydroxypyridine following UV excitation at a wavelength range of 276.9−250.0 nm is investigated using femtosecond time-resolved photoelectron imaging technique. Based on pump wavelength dependence of the decay dynamics, a refined decay picture is proposed. At pump wavelength of 276.9 nm, the S 1 state is depopulated through intersystem crossing to lower triplet state(s). At 264.0 nm, both intersystem crossing to lower triplet state(s) and internal conversion to the ground state are in operation. At 250.0 nm, internal conversion to the ground state becomes dominated.
研究领域:
化学动力学
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光物理化学
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DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2024
·
IF 10.8
Ying Chen,Lei Tian,Wen Liu,Yi Mei,Qiu-Ju Xing,Yi Mu,Ling-Ling Zheng,Qian Fu,Jian-Ping Zou,Daishe Wu
Dechlorination of chloropyridines can eliminate their detrimental environmental effects. However, traditional dechlorination technology cannot efficiently break the C–Cl bond of chloropyridines, which is restricted by the uncontrollable nonselective species. Hence, we propose the carbonate species-activated hydrogen peroxide (carbonate species/H2O2) process wherein the selective oxidant (peroxymonocarbonate ion, HCO4–) and selective reductant (hydroperoxide anion, HO2–) controllably coexist by manipulation of reaction pH. Taking 2-chloropyridine (Cl–Py) as an example, HCO4– first induces Cl–Py into pyridine N-oxidation intermediates, which then suffer from the nucleophilic dechlorination by HO2–. The obtained dechlorination efficiencies in the carbonate species/H2O2 process (32.5–84.5%) based on the cooperation of HCO4– and HO2– are significantly higher than those in the HO2–-mediated sodium hydroxide/hydrogen peroxide process (0–43.8%). Theoretical calculations confirm that pyridine N-oxidation of Cl–Py can effectively lower the energy barrier of the dechlorination process. Moreover, the carbonate species/H2O2 process exhibits superior anti-interference performance and low electric energy consumption. Furthermore, Cl–Py is completely detoxified via the carbonate species/H2O2 process. More importantly, the carbonate species/H2O2 process is applicable for efficient dehalogenation of halogenated pyridines and pyrazines. This work offers a simple and useful strategy to enhance the dehalogenation efficiency of halogenated organics and sheds new insights into the application of the carbonate species/H2O2 process in practical environmental remediation.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2024
·
IF 3.7
Zhaoyang Qi,Shiquan Zhong,Huiyun Su,Changshen Ye,Limei Ren,Ting Qiu,Jie Chen
ABSTRACT Dimethyl carbonate (DMC) is a crucial chemical raw material widely used in organic synthesis, lithium-ion battery electrolytes, and various other fields. The current primary industrial process employs a conventional sodium methoxide basic catalyst to produce DMC through the transesterification reaction between vinyl carbonate and methanol. However, the utilization of this catalyst presents several challenges during the process, including equipment corrosion, the generation of solid waste, susceptibility to deactivation, and complexities in separation and recovery. To address these limitations, a series of alkaline poly(ionic liquid)s, i.e. [DVBPIL][PHO], [DVCPIL][PHO], and [TBVPIL][PHO], with different cross-linking degrees and structures, were synthesized through the construction of cross-linked polymeric monomers and functionalization. These poly(ionic liquid)s exhibit cross-linked structures and controllable cationic and anionic characteristics. Research was conducted to investigate the effect of the cross-linking degree and structure on the catalytic performance of transesterification in synthesizing DMC. It was discovered that the appropriate cross-linking degree and structure of the [DVCPIL][PHO] catalyst resulted in a DMC yield of up to 80.6%. Furthermore, this catalyst material exhibited good stability, maintaining its catalytic activity after repeated use five times without significant changes. The results of this study demonstrate the potential for using alkaline poly(ionic liquid)s as a highly efficient and sustainable alternative to traditional catalysts for the transesterification synthesis of DMC.
研究领域:
化学工程
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材料科学
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Xiao Zhu,Shuhui Liu,Ruhui Shang,Xin Chen,Yingjie Xu,Yujun Guo,Baoping Ling
Three novel anion-functionalized proton ionic liquids (ILs) were prepared from superbase 1,5-diazabicyclic [4.3.0]non-5-nonene (DBN) and 2-hydroxypyridine (2-OP), 3-hydroxypyridine (3-OP) and 4-hydroxypyridine (4-OP). Then application of ILs in the CO 2 absorption have been investigated and the effects of temperature, pressure and humidity on the absorption properties of ILs were also studied. Experimental results demonstrated that such ionic liquids can exhibit outstanding reversibility and high CO 2 capacity at room temperature . In order to reveal the influence of position of substituents in anion on the absorption behavior, the physicochemical properties including density ( ρ ), viscosity( η ), and speed of sound ( u ) were measured at T = 298.15–328.15 K, which were used to calculate the molecular volume ( V m ), standard entropy ( S 0 ), lattice energy ( U POT ), isentropic compressibility coefficient ( κ s ) and thermal expansion coefficient ( α p ) of the pure ionic liquids at different temperatures. The results showed that [DBNH][2-OP] with O atom located in the ortho position of N atom appeared lower viscosity and larger free volumes as well as stronger alkalinity , which can endow it excellent CO 2 capture capacity of about 1.4 mol CO 2 /mol IL (about 0.3 g CO 2 /g IL) at 30 ºC. Based on quantum chemical calculation and 13 C NMR as well as FT-IR spectra, the chemical absorption mechanisms of the two active sites was proposed. These results provide important insights into effective strategies for CO 2 capture.
研究领域:
化学
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环境科学
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产品关联
DOI
高影响因子
AMB Express
·
2019
·Vol. 9
·期 1
·1-9
·
IF 2.226
Zhao Shuxue,Hu Chunhui,Guo Lizhong,Li Kuiran,Yu Hao
A 3-hydroxypyridine degrading bacterium, designated strain DW-1, was isolated from petroleum contaminated soil in Liao River China. 16S rRNA-based phylogenetic analysis indicates that strain DW-1 belongs to genus Agrobacterium. The optimal cultivation temperature and pH for strain DW-1 with 3-hydroxypyridine were 30 °C and 8.0, respectively. Under optimal conditions, strain DW-1 could completely degrade up to 1500 mg/L of 3-hydroxypyridine in 66 h. The 3-hydroxypyridine degradation pathway of strain DW-1 was suggested by HPLC and LC–MS analysis. The first reaction of 3-hydroxypyridine degradation in strain DW-1 was α-hydroxylation so that the major metabolite 2,5-dihydroxypyridine was produced, and then 2,5-dihydroxypyridine was transformed by a Fe2+-dependent dioxygenase to form N-formylmaleamic acid. N-Formylmaleamic acid will be transformed to maleic acid and fumaric acid through maleamic acid. This is the first report of the 3-hydroxypyridine degradation pathway and the utilization of 3-hydroxypyridine by a Agrobacterium sp. It may be potentially used for the bioremediation of environments polluted with 3-hydroxypyridine.
研究领域:
微生物学
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环境科学
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产品关联
DOI
PubMed
高影响因子
ENERGY & FUELS
·
2020
·
IF 3.421
Cui-Ping Ye,Rui-Nan Wang,Xia Gao,Wen-Ying Li
To screen the efficient media for CO2 capture of flue gas from power plants, a strategy for improving the CO2 capture capacity by dual functionalized ionic liquids (ILs) with multiple active sites is proposed. Three phosphonium dual functionalized ILs ([aP4443][2-Np], [aP4443][2-Op], and [aP4443][Triz]) have been prepared. The sorption capacities of the synthesized ILs under pure CO2 atmosphere and the supported ILs under different loading amounts from 10 to 50%, temperatures of 30–80 °C, and CO2 partial pressure varied from 10 to 15% were determined. Fourier transform infrared (FTIR) spectroscopy was applied to reveal the interaction between CO2 and ILs, and the pseudo-second-order model and the intraparticle diffusion model were used for a better understanding of the CO2 adsorption behavior. The results showed that a high capacity up to 1.88 mol of CO2/mol of IL for [aP4443][2-Np] is achieved, and 30% IL–MCM-41 can reach 3.19 mmol/g with excellent reversibility under the atmosphere of CO2:N2 (15%:85%) at 30 °C and 0.1 MPa. Raising the temperature or decreasing the CO2 concentration is not conducive to improving the CO2 capacity. FTIR spectroscopy demonstrated that the amino and hydroxyl react with CO2 to form NHCOO– or CO3–. Combined with the activation energy calculation, the kinetic analysis revealed that the CO2 capture of supported ILs is an internal diffusion controlled physical adsorption.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Lei Yuan,Hongshuai Gao,Haiyan Jiang,Shaojuan Zeng,Tao Li,Baozeng Ren,Xiangping Zhang
A novel type of dual-functionalized pyridinium-based ionic liquids (ILs) with acidic protons and hydroxyl groups , were designed and synthesized for ammonia (NH 3 ) absorption. The NH 3 absorption isotherms in dual-functionalized pyridinium-based ILs at temperatures from 303.15 to 343.15 K and pressures up to 600 kPa were computed using gas-liquid equilibrium method. It revealed that 4-pyridinemethanol bis(trifluoromethane)sulfonamide [4-MeOHPy][NTf 2 ] showed the maximum NH 3 solubility of 3.43 mol NH 3 /mol IL at 313.15 K and atmospheric pressure, surpassing any nonmetallic ILs previously reported. Furthermore, the characteristics of isotherms under low pressures behaved an obvious chemical reaction between ILs and NH 3 , and all experimental solubilities were regulated by a reaction equilibrium thermodynamic model (RETM). The thermodynamic properties were further obtained to better understand the NH 3 absorption process. The results indicated that this model endorses the 1:1 (NH 3 -IL) mole ratio of chemical reaction mechanism and the reaction enthalpy is main driving force of NH 3 absorption in ILs.
研究领域:
化学工程
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物理化学
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产品关联
DOI
高影响因子
MICROCHIMICA ACTA
·
2020
·Vol. 187
·期 12
·1-9
·
IF 6.232
Yang Dan,Mei Shiliang,Wen Zhuoqi,Wei Xian,Cui Zhongjie,Yang Bobo,Wei Chang,Qiu Yi,Li Min,Li Hui,Zhang Wanlu,Xie Fengxian,Wang Le,Guo Ruiqian
Dipicolinic acid (DPA) is employed as a significant biomarker to detect Bacillus anthracis , which can do serious damages to the health of human beings. Hence, it is crucial to develop a fast and highly efficient strategy for DPA monitoring. In this work, based on silicon nanoparticles (Si NPs) and terbium metal-organic frameworks (Tb-MOFs), a hybrid structure (Si NPs/Tb-MOFs) as a novel dual-emitting fluorescence probe was fabricated for ratiometric detection of DPA, where blue light-emitting Si NPs (Ex: 280 nm; Em: 422 nm) are encapsulated into green light-emitting Tb-MOFs (Ex: 280 nm; Em: 547 nm). The optical properties and chemical composition of the as-obtained Si NPs/Tb-MOFs were characterized in detail. The Si NPs/Tb-MOFs probe not merely possesses the merits of a facile synthesis method but also is an excellent fluorescence probe. The response time towards DPA is less than 30 s, revealing that the process of detecting DPA can be completed in such a short time. The limit of detection for DPA is 5.3 nM, which is four orders of magnitude lower than an infectious dosage of anthrax spores for human beings (60 μM). This dual-emitting Si NPs/Tb-MOFs probe with interference-free and self-calibrating properties may be a potential candidate for further development in medical diagnosis.
Graphical abstract
研究领域:
生物化学
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医学诊断
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材料科学
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产品关联
DOI
PubMed
高影响因子
International Journal of Nanomedicine
·
2016
·
IF 4.32
Fei Tong,Xiangyuan Tang,Xin Li,Wenquan Xia,Daojun Liu
The aim of this study was to observe the therapeutic effect of insulin-loaded linear poly(ethylene glycol)-brush-like poly(l-lysine) block copolymer poly(ethylene glycol)-b-(poly(ethylenediamine l-glutamate)-g-poly(l-lysine)) (PEG-b-(PELG-g-PLL) on renal ischemia/reperfusion-induced lung injury through downregulating hypoxia-inducible factor (HIF) as compared to free insulin. Sprague Dawley rats were pretreated with 30 U/kg insulin or insulin/PEG-b-(PELG-g-PLL) complex, and then subjected to 45 minutes of ischemia and 24 hours of reperfusion. The blood and lungs were collected, the level of serum creatinine and blood urea nitrogen were measured, and the dry/wet lung ratios, the activity of superoxide dismutase and myeloperoxidase, the content of methane dicarboxylic aldehyde and tumor necrosis factor-α, and the expression of HIF-1α and vascular endothelial growth factor (VEGF) were measured in pulmonary tissues. Both insulin and insulin/PEG-b-(PELG-g-PLL) preconditioning improved the recovery of renal function, reduced pulmonary oxidative stress injury, restrained inflammatory damage, and downregulated the expression of HIF-1α and VEGF as compared to ischemia/reperfusion group, while insulin/PEG-b-(PELG-g-PLL) significantly improved this effect.
研究领域:
药理学
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分子生物学
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病理学
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产品关联
DOI
PubMed
高影响因子
AAPS PHARMSCITECH
·
2020
·Vol. 21
·期 3
·1-10
·
IF 2.401
Li Xin,Lu Chao,Xia Wenquan,Quan Guilan,Huang Ying,Bai Xuequn,Yu Feiyuan,Xu Qian,Qin Wanbing,Liu Daojun,Pan Xin
Protein drugs were considered to be the first choice to treat many human diseases, but their clinical application was usually limited by their short half-life and lack of validated targeted therapy. Here, a series of folate-functionalized poly(ethylene glycol)- b -(poly(2-aminoethyl-L-glutamate)- g -poly(L-glutamic acid))s (FA-PEG- b -(PELG- g -PLGA)s) were designed as tumor-targeted carriers for cationic protein delivery. Compared with traditional copolymers consisting of PEG and linear charged hydrophilic blocks, FA-PEG- b -(PELG- g -PLGA) with brush-like polyelectrolyte segments were beneficial to improving their electrostatic interactions with loading protein molecules, thus increasing drug-loading stability and protecting encapsulated proteins from degradation. The designed polymer brushes could efficiently encapsulate cytochrome C (CytC), a cationic model protein, to form polyion complex (PIC) micelles with an average particle size of approximately 200 nm. An in vitro drug release study showed that the drug-loading stability of the formed PIC micelles was largely improved. The functionalization of the block copolymer carriers with a targeting folate group enhanced the tumor cell growth inhibition and total apoptotic rates induced by CytC. Our results shed light on the unique advantages of brush-like polymer carriers in delivering cationic proteins, and the poly(L-glutamic acid)-based linear-brush diblock copolymers could be applied as a versatile delivery platform for molecular targeting in cancer therapy.
研究领域:
生物材料
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药剂学
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肿瘤学
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产品关联
DOI
PubMed
高影响因子
DALTON TRANSACTIONS
·
2019
·Vol. 48
·期 7
·2300-2307
·
IF 4.052
Xiao-Yan Luo,Xiao-Yan Chen,Rong-Xing Qiu,Bao-You Pei,Yi Wei,Min Hu,Jin-Qing Lin,Jing-Yang Zhang,Geng-Geng Luo
In this work, an efficient strategy for improving CO2 capture based on anion-functionalized ionic liquids (ILs) by reducing cation–anion interactions in ILs was reported. The influence of the cationic species on CO2 absorption was investigated using 2-hydroxyl pyridium anions ([2-Op]) as a probe. CO2 capture experiments indicated that the CO2 absorption capacity in [2-Op] anion-based ILs varied from 0.94 to 1.69 mol CO2 per mol IL at 30 °C and 1 atm. Spectroscopic analysis and quantum chemical calculations suggested that the increase of the CO2 absorption capacity may be ascribed to the reduction of the strength of cation–anion interactions in ILs, and stronger cation–anion interactions would make one CO2 site in the [2-Op] anion inactive. Furthermore, the effect of the cation unit on the anion was evidenced by FT-IR spectra, implying that strong interactions between ions may lead to the decrease of the IR absorption wavenumber of hydroxy pyridium and work against CO2 capture. Following this strategy, it was finally found that [Ph-C8eim][2-Op] (Ph-C8eim = 1-N-ethyl-3-N-octyl-2-phenylimidazolium) with weaker cation–anion interactions exhibited a significant increase in the CO2 uptake capacity, and extremely high capacities of 1.69 and 1.83 mol CO2 per mol IL could be achieved at 30 and 20 °C, respectively. The study presented here would be helpful for further designing novel and effective ILs for advancing CO2 capturing performance.
研究领域:
化学工程
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Bioactive Materials
·
2022
·
IF 16.874
Yi Xiao,Haomin Yi,Jingzhi Zhu,Suhua Chen,Guofang Wang,Yilong Liao,Yuanyuan Lei,Liyin Chen,Xingcai Zhang,Fangfu Ye
Toxicity assessment is a major problem in pharmaceutical candidates and industry chemicals development. However, due to the lack of practical analytical methods for DNA adduct analysis, the safety evaluation of drug and industry chemicals was severely limited. Here, we develop a DNAzyme-based method to detect DNA adduct damage for toxicity assessment of drugs and chemicals. Among 18 structural variants of G4 DNAzyme, EA2 DNAzyme exhibits an obvious DNA damaging effect of styrene oxide (SO) due to its unstable structure. The covalent binding of SO to DNAzyme disrupts the Hoogsteen hydrogen bonding sites of G-plane guanines and affects the formation of the G4 quadruplex. DNA damage chemicals reduce the peroxidase activity of the G4 DNAzyme to monitor the DNA adduct damage by disrupting the structural integrity of the G4 DNAzyme. Our method for genotoxic assessment of pharmaceutical candidates and industrial chemicals can elucidate the complex chemical pathways leading to toxicity, predict toxic effects of chemicals, and evaluate possible risks to human health.
研究领域:
分子生物学
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毒理学
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药学
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化学工程
✓ 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）