期刊文献+
共找到132篇文章
< 1 2 7 >
每页显示 20 50 100
Fixed-Bed Column Adsorption Modeling of MnO4- Ions from Acidic Aqueous Solutions on Activated Carbons Prepared with the Biomass
1
作者 Charly Mve Mfoumou Francis Ngoye +3 位作者 Pradel Tonda-Mikiela Mbouiti Lionel Berthy Bouassa Mougnala Spenseur Guy Raymond Feuya Tchouya 《Open Journal of Inorganic Chemistry》 CAS 2023年第2期25-42,共18页
Activated carbons calcined at 400˚C and 600˚C (AC-400 and AC-600), prepared using palm nuts, collected in the town of Franceville in Gabon, were used to study the dynamic adsorption of MnO<sub>4</sub>-<... Activated carbons calcined at 400˚C and 600˚C (AC-400 and AC-600), prepared using palm nuts, collected in the town of Franceville in Gabon, were used to study the dynamic adsorption of MnO<sub>4</sub>-</sup> ions in acidic media on fixed bed column and on the kinetic modeling of experimental data of breakthrough curves of  MnO<sub>4</sub>-</sup> ions obtained. Results on the adsorption of MnO<sub>4</sub>-</sup>  ions in fixed-bed dynamics obtained on AC-400 and AC-600 adsorbents beds indicated that the AC-400 bed appears to be the most efficient in removing MnO<sub>4</sub>-</sup>  ions in acidic media. Indeed, the adsorbed amounts, the adsorbed capacities at saturation and the elimination percentage of MnO<sub>4</sub>-</sup>  ions obtained with AC-400 (31.24 mg;52.06 mg·g<sup>-1</sup> and 41.65% respectively) were higher compared to those obtained with AC-600 (9.87 mg;16.45 mg·g<sup>-1</sup> and 17.79% respectively). The breakthrough curves kinetic modeling revealed that the Thomas model and the pseudo-first-order kinetic model were the most suitable models to describe the adsorption of MnO<sub>4</sub>-</sup>  ions on adsorbents studied in our experimental conditions. The results of the intraparticle diffusion model showed that intraparticle diffusion was involved in the adsorption mechanism of MnO<sub>4</sub>-</sup>  ions on investigated adsorbents and was not the limiting step and the only process controlling MnO<sub>4</sub>-</sup>  ions adsorption. In contrast to AC-400, the intraparticle diffusion on AC-600 bed plays an important role in the adsorption mechanism of MnO<sub>4</sub>-</sup>  ions. 展开更多
关键词 acidic Media MnO4 style=margin-left:-6px >- BIOMASS Activated Carbon Dynamic Adsorption Kinetics Models
下载PDF
Chlorogenic acid alleviates hypoxic-ischemic brain injury in neonatal mice 被引量:4
2
作者 Lu-Yao Li Qi Wang +9 位作者 Lu Deng Zhen Lin Jing-Jing Lin Xin-Ye Wang Tian-Yang Shen Yi-Hui Zheng Wei Lin Pei-Jun Li Xiao-Qin Fu Zhen-Lang Lin 《Neural Regeneration Research》 SCIE CAS CSCD 2023年第3期568-576,共9页
Recent studies have shown that chlorogenic acid(CGA),which is present in coffee,has protective effects on the nervous system.However,its role in neonatal hypoxic-ischemic brain injury remains unclear.In this study,we ... Recent studies have shown that chlorogenic acid(CGA),which is present in coffee,has protective effects on the nervous system.However,its role in neonatal hypoxic-ischemic brain injury remains unclear.In this study,we established a newborn mouse model of hypoxic-ischemic brain injury using a modified Rice-Vannucci method and performed intraperitoneal injection of CGA.We found that CGA intervention effectively reduced the volume of cerebral infarct,alleviated cerebral edema,restored brain tissue structure after injury,and promoted axon growth in injured brain tissue.Moreover,CGA pretreatment alleviated oxygen-glucose deprivation damage of primary neurons and promoted neuron survival.In addition,changes in ferroptosis-related proteins caused by hypoxic-ischemic brain injury were partially reversed by CGA.Furthermore,CGA intervention upregulated the expression of the key ferroptosis factor glutathione peroxidase 4 and its upstream glutamate/cystine antiporter related factors SLC7A11 and SLC3A2.In summary,our findings reveal that CGA alleviates hypoxic-ischemic brain injury in neonatal mice by reducing ferroptosis,providing new ideas for the treatment of neonatal hypoxic-ischemic brain injury. 展开更多
关键词 chlorogenic acid ferroptosis glutathione peroxidase 4 lipid peroxidation neonatal hypoxic-ischemic brain injury NEURONS NEUROPROTECTION oxidative stress oxygen-glucose deprivation system Xc^(-)
下载PDF
Δ4-3-oxosteroid-5β-reductase deficiency: Responses to oral bile acid therapy and long-term outcomes 被引量:7
3
作者 Mei-Hong Zhang Kenneth DR Setchell +3 位作者 Jing Zhao Jing-Yu Gong Yi Lu Jian-She Wang 《World Journal of Gastroenterology》 SCIE CAS 2019年第7期859-869,共11页
BACKGROUND Disorders of primary bile acid synthesis may be life-threatening if undiagnosed,or not treated with primary bile acid replacement therapy. To date, there are few reports on the management and follow-up of p... BACKGROUND Disorders of primary bile acid synthesis may be life-threatening if undiagnosed,or not treated with primary bile acid replacement therapy. To date, there are few reports on the management and follow-up of patients with Δ4-3-oxosteroid 5β-reductase(AKR1 D1) deficiency. We hypothesized that a retrospective analysis of the responses to oral bile acid replacement therapy with chenodeoxycholic acid(CDCA) in patients with this bile acid synthesis disorder will increase our understanding of the disease progression and permit evaluation of this treatment regimen as an alternative to the Food and Drug Administration(FDA) approved drug cholic acid, which is currently unavailable in China.AIM To evaluate the therapeutic responses of patients with AKR1 D1 deficiency to oral bile acid therapy, specifically CDCA.METHODS Twelve patients with AKR1 D1 deficiency, confirmed by fast atom bombardment ionization-mass spectrometry analysis of urine and by gene sequencing for mutations in AKR1 D1, were treated with differing doses of CDCA or ursodeoxycholic acid(UDCA). The clinical and biochemical responses to therapy were monitored over a period ranging 0.5-6.4 years. Dose adjustment, to optimize the therapeutic dose, was based on changes in serum biochemistry parameters,notably liver function tests, and suppression of the urinary levels of atypical hepatotoxic 3-oxo-Δ4-bile acids measured by mass spectrometry.RESULTS Physical examination, serum biochemistry parameters, and sonographic findings improved in all 12 patients during bile acid therapy, except one who underwent liver transplantation. Urine bile acid analysis confirmed a significant reduction in atypical hepatotoxic 3-oxo-Δ4 bile acids concomitant with clinical and biochemical improvements in those patients treated with CDCA. UDCA was ineffective in down-regulating endogenous bile acid synthesis as evidenced from the inability to suppress the urinary excretion of atypical 3-oxo-Δ4-bile acids. The dose of CDCA required for optimal clinical and biochemical responses varied from 5.5-10 mg/kg per day among patients based on maximum suppression of the atypical bile acids and improvement in serum biochemistry parameters, and careful titration of the dose was necessary to avoid side effects from CDCA.CONCLUSION The primary bile acid CDCA is effective in treating AKR1 D1 deficiency but the therapeutic dose requires individualized optimization. UDCA is not recommended for long-term management. 展开更多
关键词 Δ4-3-oxosteroid--reductase DEFICIENCY Mass SPECTROMETRY BILE acid synthesis DISORDER Chenodeoxycholic acid Ursodeoxycholic acid
下载PDF
Effects of ω-3 fatty acids on toll-like receptor 4 and nuclear factor-κB p56 in lungs of rats with severe acute pancreatitis 被引量:12
4
作者 Bin Wang Xiao-Wei Wu +4 位作者 Mei-Xia Guo Min-Li Li Xiao-Bing Xu Xin-Xin Jin Xiao-Hua Zhang 《World Journal of Gastroenterology》 SCIE CAS 2016年第44期9784-9793,共10页
AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 5... AIM To determine the effects of ω-3 fatty acids(ω-3FA) on the toll-like receptor 4(TLR4)/nuclear factor κB p56(NF-κBp56) signal pathway in the lungs of rats with severe acute pancreatitis(SAP).METHODS A total of 56 Sprague-Dawley rats were randomly divided into 4 groups: control group, SAP-saline group, SAP-soybean oil group and SAP-ω-3FA group. SAP was induced by the retrograde infusion of sodium taurocholate into the pancreatic duct. The expression of TLR4 and NF-κBp56 in the lungs was evaluated by immunohistochemistry and Western blot analysis. The levels of inflammatory cytokines interleukin-6 and tumor necrosis factor-alpha in the lungs were measured by enzyme-linked immunosorbent assay. RESULTS The expression of TLR4 and NF-κBp56 in lungs and of inflammatory cytokines in serum significantly increased in the SAP group compared with the control group(P < 0.05), but was significantly decreased in the ω-3FA group compared with the soybean oil group at 12 and 24 h(P < 0.05).CONCLUSION During the initial stage of SAP, ω-3FA can efficiently lower the inflammatory response and reduce lung injury by triggering the TLR4/NF-κBp56 signal pathway. 展开更多
关键词 Severe acute pancreatitis ω-3 fatty acids Lung injury Toll-like receptor 4 Nuclear factor-κB p56 CYTOKINE
下载PDF
An efficient route towards R-2-phenoxypropionic acid synthesis for biotransformative production of R-2-(4-hydroxyphenoxy)propionic acid 被引量:3
5
作者 Haiyan Zhou Yizuo Li +4 位作者 Rui Jiang Xianlin Wang Yuanshan Wang Yaping Xue Yuguo Zheng 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第4期315-323,共9页
R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2p... R2(4hydroxyphenoxy)propionic acid(RHPPA)is a key intermediate for the synthesis of classic herbicides with high selectivity against grassy weed.The main route for RHPPA biosynthesis is to hydroxylate the substrate R2phenoxypropionic acid(RPPA)at C4 position with microbes.In order to provide sufficient RPPA for the industrial production of RHPPA,an effective RPPA synthesis method was established and optimized in this work.The synthesis process mainly consisted of two steps:(1)synthesis of S2chloropropionic acid from Lalanine via diazotization and chlorination reactions;and(2)synthesis of RPPA from S2chloropropionic acid and phenol via etherification reaction.The optimal reaction conditions were as follows:HCl:NaNO_(2):KI:LAla=2.0:1.2:0.7:1.0(in molar),125℃reflux for 1.5 h,with KI as catalyst,and KI:S2chloropropionic acid:phenol=0.075:1.2:1.0(in molar).Under these conditions,an improved molar conversion rate(74.9%,calculated in phenol)was achieved.After extraction using anionic exchange resin Amberlite IRA400(CI),RPPA product with a purity of 95.08%was obtained.The purified RPPA was identified and evaluated in the application of the biotransformative production of RHPPA.The results indicated that the synthesized RPPA supported the RHPPA biosynthesis with a comparable yield as that of the standard RPPA.The RPPA synthesis method provided herein exhibited the advantages of low price and easy availability of raw materials,less toxicity of reagents,simple manipulations,and low equipment/instrument requirements. 展开更多
关键词 R-2-phenoxypropionic acid R-2-(4-hydroxyphenoxy)propionic acid BIOSYNTHESIS S-2-chloropropionic acid
下载PDF
1D Lanthanide Coordination Polymers Based on 3-(Pyridin-4-yl)benzoic Acid: Syntheses, Structures and Luminescent Properties 被引量:4
6
作者 肖雪英 韦永勤 +1 位作者 郑文旭 吴克深 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2011年第11期1543-1550,共8页
ABSTRACT Four novel 1D lanthanide coordination polymers with formula [Ln(3,4-pybz)3(HzO)2. H2O]n (Ln = 1 Sm; 2 Eu; 3 Tb; 4 Dy, 3,4-Hpybz = 3-(pyridin-4-yl)benzoic acid) have been synthesized by hydrothermal re... ABSTRACT Four novel 1D lanthanide coordination polymers with formula [Ln(3,4-pybz)3(HzO)2. H2O]n (Ln = 1 Sm; 2 Eu; 3 Tb; 4 Dy, 3,4-Hpybz = 3-(pyridin-4-yl)benzoic acid) have been synthesized by hydrothermal reactions of lanthanide oxide and 3-(pyridine-4-yl) benzoic acid. Single-crystal X-ray diffraction shows that the four compounds are isostructural. They all crystallize in a monoelinic system, space group P1^-. They have a doubly carboxylate-bridged infinite-chain structure with alternating Ln-(carboxylate)2-Ln linkages and one chelating carboxylate group on each metal center. The Ln ion also combines to two water molecules to form an eight-coordinate square antiprismatic geometry. The pyridine nitrogen atoms of the ligand do not coordinate to the metal centers but direct the formation of a 3D network through hydrogen bonding with coordinated water molecules. The photoluminescent properties of 2 and 3 have been also studied. 展开更多
关键词 lanthanide coordination polymer 3-(pyridine-4-yl) benzoic acid HYDROGEN-BONDING photoluminescence
下载PDF
Synthesis, Structure and Photoluminescence of a New Cd(Ⅱ) Coordination Polymer Based on 4-(Carboxymethoxy)-benzoic Acid and 1,10-Phenanthroline Derivative 被引量:6
7
作者 孔治国 张艳娜 刘福义 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第8期1175-1179,共5页
A new ID coordination polymer, [Cda(L1)2(L2)2].H2O (1, H2L1 = 4-(carboxy- methoxy)benzoic acid and L2 = 2-(4-fluorophenyl)-I H-imidazo[4,5-f][1,10]phenanthroline), has been hydrothermally synthesized and cha... A new ID coordination polymer, [Cda(L1)2(L2)2].H2O (1, H2L1 = 4-(carboxy- methoxy)benzoic acid and L2 = 2-(4-fluorophenyl)-I H-imidazo[4,5-f][1,10]phenanthroline), has been hydrothermally synthesized and characterized by elemental analysis and single-crystal X-ray diffraction. It crystallizes in triclinic, space group P1 with a = 9.985(5), b = 10.768(5), c = 12.512(5) A, a = 68.959(5), β = 80.354(5), γ = 79.663(5)°, V= 1227.4(10) A3, Z = 1, C56H36Cd2F2N8O11, Mr = 1259.73, Dc = 1.704 g/cm3, F(000) = 630, μ(MoKa) = 0.949 mm-1, R = 0.0261 and wR = 0.0655. The L1 anions link the neighboring Cd(II) atoms to form a 1D double chain structure. The L2 ligands are alternately located on both sides of the double chains. More interestingly, the lateral L2 ligands from adjacent double chains are paired to furnish strong π-π interactions, yielding a 2D supramolecular layer. N-H...O, O-H...N and O-H...O hydrogen bonds further stabilize the structure of 1. The luminescent property of 1 was studied in solid state at room temperature. 展开更多
关键词 crystal structure coordination polymer 4-(carboxymethoxy)benzoic acid2-4-flnorophenyl)-lH-imidazo[4 5-f] [ 1 10]phenanthroline
下载PDF
Hydrothermal Syntheses and Crystal Structures of Six Complexes Constructed from 1,3,5-Benzenetricarboxylic Acid and 4'-(4-Pyridyl)-2,2':6',2''-terpyridine Mixed Ligands 被引量:4
8
作者 乔宇 王炫博 +4 位作者 周艳凤 刘力辉 车广波 刘春波 刘晓腾 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2017年第8期1381-1394,共14页
Six new transition metal complexes, [Zn(HBTC)(PYTPY)]n·n PYTPY(1), [Cu(HBTC)(PYTPY)]n·n PYTPY(2), [Co(HBTC)(PYTPY)]n·n DMF(3), [Mn(HBTC)(PYTPY)]n·n DMF(4), [Cd(HBTC)(PYTP... Six new transition metal complexes, [Zn(HBTC)(PYTPY)]n·n PYTPY(1), [Cu(HBTC)(PYTPY)]n·n PYTPY(2), [Co(HBTC)(PYTPY)]n·n DMF(3), [Mn(HBTC)(PYTPY)]n·n DMF(4), [Cd(HBTC)(PYTPY)(H2O)]n·2nH2O(5), and [Co(HBTC)(PYTPY)(H2O)2](6),(H3BTC = 1,3,5-benzenetricarboxylic acid, PYTPY = 4'-(4-pyridyl)-2,2':6',2''-terpyridine, DMF = N,N?-dimethylformamide), have been synthesized and characterized by elemental analysis, IR and X-ray single-crystal diffraction. Complexes 1~5 all feature one-dimensional chain structures, and complex 6 exhibits a zero-dimensional structure. Complexes 1~5 present three-dimensional(3D) supramolecular frameworks via π-π stacking interactions, whenas 6 has also a 3D supramolecular structure assembled by hydrogen bonding. Meanwhile, complexes 1 ~ 6 exhibit the thermal stabilities and photoluminescent properties. 展开更多
关键词 transition metal complex 1 3 5-benzenetricarboxylic acid 4'-4-pyridyl)-2 2' 6' 2''-terpyridine crystal structure
下载PDF
Synthesis and Crystal Structure of a New Copper(II) Complex with 4-Cyanobenzoic Acid 被引量:6
9
作者 LI Yan WU A-Qing +3 位作者 ZHENG Fa-Kun GUO Guo-Cong LU Can-Zhong HUANG Jin-Shun 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2005年第11期1281-1285,共5页
A new Cu(Ⅱ) complex [Cu(4-cba)(1,10-phen)(H2O)2](NO3) (4-Hcba = 4-cyanobenzoic acid) has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100 ℃ and structurally characteriz... A new Cu(Ⅱ) complex [Cu(4-cba)(1,10-phen)(H2O)2](NO3) (4-Hcba = 4-cyanobenzoic acid) has been synthesized by solvothermal reaction in an ethanol/water mixed solution at 100 ℃ and structurally characterized by single-crystal X-ray diffraction. Crystallographic data: C20H16CuN4O7, Mr= 487.91, triclinic, space group PI, a = 7.8420(2), b = 9.1070(2), c = 15.1140(6) A, a = 76.889(9), β = 81.332(11), γ = 74.844( 11)°, V = 1009.89(5) A^3, Z = 2, Dc = 1.605 g/cm^3, F(000) = 498, μ = 1.134 mm^-1, the final R = 0.0379 and wR = 0.0865 for 2977 observed reflections with 1 〉 2σ(Ⅰ). The Cu(Ⅱ) atom is coordinated by two terminal water molecules, one chelating 1,10-phen molecule and one monodentate 4-cba ligand to form a slightly distorted square pyramid. The title complex molecules are connected through hydrogen bonds and π-π stacking interactions to generate a 2D layered network. The thermogravimetric analysis of the title complex has also been discussed. 展开更多
关键词 copper(Ⅱ) complex 4-cyanobenzoic acid crystal structure hydrogen bonds π-π stacking
下载PDF
Crystal Structure, Thermal Behavior and Luminescence of a New Copper Coordination Polymer Constructed with 4-(Carboxymethoxy)-benzoic Acid 被引量:3
10
作者 WANG Xiu-Yan LI Guan-Ting +3 位作者 WANG Heng SONG Yu LIU Dong-Xue XU Zhan-Lin 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2019年第4期629-634,共6页
A new Cu(Ⅱ) coordination polymer, [Cu(L1)(L2)](1), was synthesized under hydrothermal conditions(H_2L1 = 4-(carboxymethoxy)benzoic acid, L2 = 2-(4-fluorophenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline). Crystallograph... A new Cu(Ⅱ) coordination polymer, [Cu(L1)(L2)](1), was synthesized under hydrothermal conditions(H_2L1 = 4-(carboxymethoxy)benzoic acid, L2 = 2-(4-fluorophenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline). Crystallographic data for 1: triclinic, space group P1 with a = 9.750(5), b = 10.148(5), c = 12.869(5) ?, α = 104.904(5), β = 102.133(5), γ = 95.219(5)°, V = 1188.7(10) ?~3, Z = 2, C_(28)H_(17)FN_4O_5Cu, Mr = 572.01, D_c = 1.598 g/cm^3, F(000) = 582, μ(MoKa) = 0.977 mm^(-1), R = 0.0474 and w R = 0.1144. The TGA behaviors and luminescence of 1 have been studied in detail. The L1 dianions link neighboring Cu(Ⅱ) atoms in a bis-chelating mode, yielding a one-dimensional chain structure along the b axis. The L2 ligands are attached on one side of the chain through chelating the Cu(Ⅱ) atoms, and are stacked with those of an adjacent chain through π-π interactions, yielding a layer structure. Additionally, the N–H???O hydrogen bonds further stabilize the structure of 1. 展开更多
关键词 crystal structure COORDINATION polymer 4-(carboxymethoxy)benzoic acid copper(Ⅱ) LUMINESCENT property
下载PDF
Syntheses, Structures and Photoluminescence of the Cadmium(Ⅱ) and Copper(Ⅱ) Complexes Based on 4'-(4''-Pyridyl)-2,2':6',2''-terpyridine and 1,4-Benzenedicarboxylic Acid Ligands 被引量:3
11
作者 张兴晶 王璐瑶 +2 位作者 尉兵 张文通 车广波 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第7期1069-1079,共11页
Two new metal-organic complexes [Cd2(1,4-BDC)(4-pytyp)(H2O)4]·(1,4-BDC)(1) and [Cu2(1,4-BDC)(4-pytyp)2(H2O)2]·(1,4-BDC)·8H2O(2)(4-pytyp = 4'-(4''-pyridyl)-2,2':6',2''-terp... Two new metal-organic complexes [Cd2(1,4-BDC)(4-pytyp)(H2O)4]·(1,4-BDC)(1) and [Cu2(1,4-BDC)(4-pytyp)2(H2O)2]·(1,4-BDC)·8H2O(2)(4-pytyp = 4'-(4''-pyridyl)-2,2':6',2''-terpyridine, 1,4-H2 BDC = 1,4-benzenedicarboxylic acid) have been synthesized under hydrothermal conditions and characterized by elemental analysis, infrared analysis and X-ray single-crystal diffraction. The scrutiny of single-crystal structure reveals that complex 1 forms to a 3D supramolecular network linked by π-π stacking interactions and hydrogen bonds. X-ray diffraction analysis reveals that complex 2 exhibits a 3D supramolecular network linked through complicated hydrogen bonds. The thermogravimetric analysis and photoluminescent properties of 1 and 2 are discussed in detail. 展开更多
关键词 cadmium(Ⅱ) complex copper(Ⅱ) complex 4-4''-pyridyl)-2 2':6' 2''-terpyridine 1 4-benzenedicarboxylic acid crystal structure
下载PDF
A Study on Side Reactions of Hydroxyethylation of 3-Nitro-4- chlorobenzenesulfinic Acid with Ethylene Oxide 被引量:2
12
作者 Zhen Tang DONG Zu Wang WU +2 位作者 Zhi Wei WANG Yun De WANG Yin Zhou YU 《Chinese Chemical Letters》 SCIE CAS CSCD 2006年第5期613-616,共4页
The reaction of 3-nitro-4-chlorobenzenesulfinic acid and ethylene oxide to obtain 2-nitro-4-(β-hydroxyethylsulfonyl)chlorobenzene had been studied. Except hydroxyethylation on the sulfur atom of 3-nitro-4-chloroben... The reaction of 3-nitro-4-chlorobenzenesulfinic acid and ethylene oxide to obtain 2-nitro-4-(β-hydroxyethylsulfonyl)chlorobenzene had been studied. Except hydroxyethylation on the sulfur atom of 3-nitro-4-chlorobenzenesulfinic acid to form the target product, 2-nitro-4-(β- hydroxyethylsulfonyl)chlorobenzene, there presented three kinds of side reactions: 1. Condensation and elimination of HCI to form biphenyl sulfone derivatives; 2. Addition to give bisulfonyl ethane derivative via vinyl sulfone; and 3. Hydroxylethylation on O-atom to produce hydroxylethylsulfinate due to the tautomerism of sulfinic acid. 展开更多
关键词 Hydroxyethyl-2-nitrochlorobenzene-4-sulfinate 3-nitro-4-chlorobenzenesulfinic acid 2-nitro-4-(β- hydroxyethylsulfonyl)chlorobenzene.
下载PDF
A Green Synthesis of 2-Ethylanthraquinone by Dehydration of 2-(4'-ethylbenzoyl) benzoic Acid over Solid Acid Catalysts 被引量:1
13
作者 Ren Shu XU Xin Wen GUO Gui Ru WANG Zhu Xia ZHANG 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第12期1587-1589,共3页
The dehydration of 2-(4'-ethylbenzoyl) benzoic acid (BE acid) to 2-ethylanthraquinone (2-EAQ) was investigated over solid acid catalysts. The results showed that H-beta zeolite catalyst modified by dilute HNO3 ... The dehydration of 2-(4'-ethylbenzoyl) benzoic acid (BE acid) to 2-ethylanthraquinone (2-EAQ) was investigated over solid acid catalysts. The results showed that H-beta zeolite catalyst modified by dilute HNO3 solution exhibited an excellent performance. In our study, the conversion of BE acid can reach 96.7%, and the selectivity to 2-EAQ is up to 99.6%. 展开更多
关键词 2-ETHYLANTHRAQUINONE 2-4-ethylbenzoyl) benzoic acid H-BETA DEHYDRATION
下载PDF
Enantioselective esterification of(R,S)-2-(4-methylphenyl)propionic acid via Novozym 435:Optimization and application 被引量:1
14
作者 Xin Yuan LujunWang +2 位作者 Panliang Zhang Weifeng Xu Kewen Tang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第7期1816-1823,共8页
This paper reports on the resolution of(R,S)-2-(4-methylphenyl)propionic acid(MPPA)enantiomers by enzymatic esterification in organic solvent.Novozym 435(CALB)has the best catalytic performance compared with other lip... This paper reports on the resolution of(R,S)-2-(4-methylphenyl)propionic acid(MPPA)enantiomers by enzymatic esterification in organic solvent.Novozym 435(CALB)has the best catalytic performance compared with other lipases.Of the alcohols screened,n-hexanol is the best acyl acceptor and gives the highest enzyme activity and enantioselectivity in n-hexane.Response surface methodology(RSM)was used to evaluate the influence of the factors,such as temperature,enzyme amount,substrate concentration and reaction time on the substrate conversion(c)and enantiomeric excess(ee).The correlation coefficient R2 for enantiomeric excess and the conversion are 0.9827 and 0.9910,respectively,indicating that can accurately predict the experimental results.By simulation and optimization,the optimal conditions were obtained,involving 600 mmol·L^-1 MPPA concentration(0.60 mmol),850 mmol·L^-1 hexanol concentration(0.85 mmol),58 mg enzyme amount,75℃temperature and 4.5 h reaction time,respectively.Under the optimized conditions,the experimental values of conversion and enantiomeric excess were 89.34%and 97.84%,respectively,which are in good agreement with the model predictions. 展开更多
关键词 (R S)-2-(4-Methylphenyl)propionic acid Novozym 435 ESTERIFICATION kinetic resolution Response surface methodology
下载PDF
Synthesis and Crystal Structure of 4-(4,6-dimethoxyl -pyrimidin-2-yl)-3-thiourea Carboxylic Acid Methyl Ester 被引量:1
15
作者 HUANG Jie SONG Ji-Rong REN Ying-Hui XU Kang-Zhen MA Hai-Xia 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 北大核心 2006年第2期168-172,共5页
The title compound 4-(4,6-dimethoxylpyrimidin-2-yl)-3-thiourea carboxylic acid methyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in eth... The title compound 4-(4,6-dimethoxylpyrimidin-2-yl)-3-thiourea carboxylic acid methyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single crystals suitable for X-ray measurement were obtained by recrystallization with the solvent of dimethyl formamide at the room temperature. The structure was characterized by elemental analysis and IR and determined by X-ray diffraction analysis' Crystallographic data: C9H12N4O4S, Mr = 272.29, monoclinic, space group C2/m with a = 1.6672(3), b = 0.66383(12), c = 1.1617(2) nm, β = 109.275(2)°, V = 1.2136(4) nm^3, Dc = 1.490 g/cm^3,μ = 0.281 mm^-1, F(000) = 568, Z = 4, R1 = 0.0341and wR2 = 0.1042. 展开更多
关键词 4-4 6-dimethoxylpyrimidin-2-yl)-3-thiourea carboxylic acid methyl ester synthesis X-ray diffraction
下载PDF
A One-dimensional Cd(Ⅱ)Coordination Polymer Constructed from 1,4-Benzene-dicarboxylic Acid and 3-(2,6-Di(pyrazin-2-yl)pyridin-4-yl)-1H-indole:Synthesis,Structure and Photoluminescence 被引量:2
16
作者 谢玲 卢丽萍 朱苗力 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第10期1606-1614,共9页
A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-... A new coordination polymer {[Cd(C_(21)H_(14)N_6)(C_8H_4O_4)]·H_2O}_n(1) was synthesized by an elaborate design via the reaction of 3-(2,6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole(bppi),1,4-benzene-dicarboxylic acid(H2bdc) and cadmium(Ⅱ) nitrate in CH_3OH/H_2O mixed solvents. Complex 1 crystallizes in orthorhombic,space group Ccca with a = 20.012(4),b = 31.881(6),c = 19.808(4) ?,V = 12638(4) ?~3,Z = 16,C_(29)H_(20)CdN_6O_5,M_r = 644.91,D_c = 1.356 g·cm^(-3),μ = 0.735 mm^(-1),F(000) = 5184,GOOF = 1.046,the final R = 0.0405 and wR = 0.1063 for 6870 observed reflections(I 〉 2σ(I)). The Cd(Ⅱ) centre is hepta-coordinated by three N and four O atoms from one bppi terminal ligand and two bdc2– ligands,respectively,displaying a capped trigonal prism geometry. Structure extension gives coordination polymeric chains,in which the bdc2– linkers connect Cd(Ⅱ) cations into a one-dimensional(1D) coordination polymer along the c axis,giving zigzag chains with the Cd···Cd separation of 11.178(1) ?. The adjacent bppi terminal ligands in the chains are anti-periplanar conformation. The three-dimensional(3D) structure is stabilized by π···π stacking and hydrogen-bonding interactions to form a supramolecular self-penetrating network with 1D channels. In 1,there are voids 2999.7 ?~3 with 23.7% of per unit cell volume. Thermal analysis indicates that the framework of 1 is stable until 651 K and the photoluminescence of 1 in the solid shows very weak fluorescence at 382 and 560 nm upon excitation at 310 nm. 展开更多
关键词 1 4-benzenedicarboxylic acid 3-(2 6-di(pyrazin-2-yl)pyridin-4-yl)-1H-indole one-dimensional cadmium(Ⅱ) coordination polymer π···π stacking interactions photoluminescence
下载PDF
Syntheses, Crystal Structures and Properties of Two Metal-organic Complexes Based on 5-(4-Pyridyl)-methoxyl Isophthalic Acid 被引量:1
17
作者 陶兆林 覃玲 郑和根 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第7期1067-1075,共9页
Two new metal-organic frameworks, [Co3L2(NO2)2(H2O)2],, (1) and{[Ni(L)(H2O)5] (H2O)2.DMF}, (2, H2L = 5-(4-pyridyl)-methoxyl isophthalic acid), have been synthesized by the hydrothermal method and chara... Two new metal-organic frameworks, [Co3L2(NO2)2(H2O)2],, (1) and{[Ni(L)(H2O)5] (H2O)2.DMF}, (2, H2L = 5-(4-pyridyl)-methoxyl isophthalic acid), have been synthesized by the hydrothermal method and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis (TGA) and X-ray crystallography. Compound 1 crystallizes in the monoclinic system with space group P2/c and adopts a slightly distorted octahedral configuration. In compound 1, the 2D bilayered structures are linked by O-H...O and O-H...N hydrogen bonds to form a 3D framework. Compound 2 crystallizes in the monoclinic system with space group P2/n, and the central nickel atoms are octa-coordinated with five O atoms from coordinated water molecules and one N atom from one H2L ligand. The abundant O-H…O hydrogen bonds and π…π interactions link the molecules into a 3D framework. In addition, compounds 1 and 2 exhibit strong ultraviolet absorption in the solid state at room temperature. 展开更多
关键词 5-4-pyridyl)-methoxyl isophthalic acid 2D bilayered structure hydrogen bond π…π stacking
下载PDF
A Zn(Ⅱ) Coordination Polymer Based on a Flexible Polycarboxylate Ligand 5-(4-Hydroxypyridinium-1-ylmethyl)-isophthalic Acid: Synthesis, Structure, and Property 被引量:1
18
作者 李付安 杨维春 李青彬 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2018年第4期645-652,共8页
A Zn(Ⅱ) supramolecular coordination polymer, {[Zn2(L)2(m-bix)(H20)]6H2O}n(1), with an interesting 1D→2D polythreading array from a flexible and angular organic aromaticpolycarboxylate ligand 5-(4-hydroxyp... A Zn(Ⅱ) supramolecular coordination polymer, {[Zn2(L)2(m-bix)(H20)]6H2O}n(1), with an interesting 1D→2D polythreading array from a flexible and angular organic aromaticpolycarboxylate ligand 5-(4-hydroxypyridinium-l-ylmethyl)isophthalic acid (H2L), and N-donorligand 1,3-bis(imidazol-l-ylmethyl)benzene (m-bix), has been obtained under hydrothermalconditions and characterized by elemental analysis, powder X-ray diffraction (PXRD), IR, thermalgravimetric analyses (TGA) and single-crystal X-ray diffraction. In 1, the Zn(Ⅱ) center has twocoordination geometries. One exhibits a trigonal bipyramidal coordination sphere, and the other isa tetrahedral geometry; L2- has two different coordination modes, with one connecting three Zn(Ⅱ)ions through two monodentate carboxylate groups and the monodentate hydroxyl group, and theother bridging two Zn(Ⅱ) ions through two carboxylate groups. The L2- anions connect the Zn(Ⅱ)centers forming an infinite 1D tubular structure. These 1D tubes are interconnected by the m-bixspacers to form a 2D framework. Such 2D layers are further assembled into a 3D supramolecularnetwork via hydrogen bonds. Meanwhile, the luminescent property of 1 has also been investigatedin detail. 展开更多
关键词 5-4-hydroxypyridinium-1-ylmethyl)isophthalic acid 1 3-bis(imidazol-1-ylmethyl)benzene ZINC PXRD 1D→2D polythreading array
下载PDF
Syntheses and Crystal Structures of Two Zn(Ⅱ) Coordination Polymers Constructed with 4,4'-(Dihydroxymethylene)dibenzoic Acid
19
作者 秦兰 许兰平 韩磊 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2013年第1期113-119,共7页
Two new isomorphous metal-organic coordination polymers, [Zn(dhmdb)(2,2'- bpy)]n 1 and [Zn(dhmdb)(1,10-phen)]n 2, have been obtained under hydrothermal reactions from 4,4'-(dihydroxymethylene)dibenzoic ac... Two new isomorphous metal-organic coordination polymers, [Zn(dhmdb)(2,2'- bpy)]n 1 and [Zn(dhmdb)(1,10-phen)]n 2, have been obtained under hydrothermal reactions from 4,4'-(dihydroxymethylene)dibenzoic acid (H2dhmdb), Zn(NO3)2·6H2O and 2,2'-pyridine or 1,10- phenanthroline, respectively. Compounds 1 and 2 have been characterized by FT-IR spectroscopy, thermal analysis and single-crystal X-ray diffraction. The zigzag chains of 1 and 2 are linked into three-dimensional supramolecular networks by both O–H…O hydrogen bonds and π…π stacking interactions. Crystal data for 1: ZnC25H18N2O6, Mr = 507.78, orthorhombic, space group Pbca, a = 14.031(3), b = 10.826(2), c = 27.343(6), V = 4153.5(14)3, Z = 8, Dc = 1.624 g/cm3, F(000) = 2080, μ = 1.231 mm-1, R = 0.0699 and wR = 0.1829. Crystal data for 2: ZnC27H18N2O6, Mr = 531.80, orthorhombic, space group Pbca, a = 13.796(3), b = 10.809(2), c = 28.612(6), V = 4266.8(15)3, Z = 8, Dc = 1.656 g/cm3, F(000) = 2176, μ = 1.203 mm-1, R = 0.0454 and wR = 0.1399. 展开更多
关键词 coordination polymers crystal structures zigzag chains 4 4-(dihydroxymethylene)dibenzoic acid
下载PDF
Two 3D Metal-organic Frameworks with 4-Fold [2+2]-type Interpenetrated hms Nets Based on a Flexible Tricarboxylic Acid
20
作者 樊义康 谢斌 +4 位作者 谢峰 吴威平 邹立科 那仁.格日勒 魏健 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2016年第4期605-614,共10页
Two 3D 4-fold interpenetrated metal-organic frameworks, [Mn(L)(bpy)]n (1) and [Cu(HL)(bpy)]n (2)(H3L = 4,4',4''-(benzene-1,3,5-triyl-tri(methyleneoxy)) tribenzoic acid, bpy = 4,4′-bipyridine), we... Two 3D 4-fold interpenetrated metal-organic frameworks, [Mn(L)(bpy)]n (1) and [Cu(HL)(bpy)]n (2)(H3L = 4,4',4''-(benzene-1,3,5-triyl-tri(methyleneoxy)) tribenzoic acid, bpy = 4,4′-bipyridine), were synthesized under hydrothermal conditions, and characterized by element analyses, IR spectra, thermogravimetric analyses, X-ray powder diffraction and magnetic property studies. The single-crystal X-ray analyses revealed that 1 and 2 are homogeneous. 1 crystallizes in monoclinic, space group Cc with a = 26.794(2), b = 11.6346(10), c = 21.4614(18) ?, β = 91.570(2)°, V = 6687.9(10) A^3, Z = 8, Mr = 736.59, D = 1.463 g·cm^(-3), μ = 0.458 mm^-1c, R(int) = 0.0524, F(000) = 3040, the final R = 0.0844 and wR = 0.2266 for 8092 observed reflections(I 〉 2σ(I)). 2 crystallizes in monoclinic, space group Cc with a = 27.609(12), b = 11.126(10), c = 21.490(9) ?, β = 92.131(2)°, V = 6597(5) A^3, Z = 8, Mr = 746.21, Dc = 1503 g·cm^(-3), μ = 0.726 mm^-1, R(int) = 0.0542, F(000) = 3080, the final R =0.0681 and wR = 0.1831 for 6777 observed reflections(I 〉 2σ(I)). Two compounds are 3D [2+2]-type 4-fold interpenetrated frameworks with(6^3)(6^9.8) hms topology. The magnetic study of compound 2 shows the presence of weak antiferromagnetic interaction between the Cu^Ⅱ ions in 2. 展开更多
关键词 metal-organic frameworks 4 4 4''-(benzene-1 3 5-triyl-tri(methyleneoxy)) tribenzoic acid 4-fold interpenetration hms networks
下载PDF
上一页 1 2 7 下一页 到第
使用帮助 返回顶部