期刊文献+
共找到4,066篇文章
< 1 2 204 >
每页显示 20 50 100
Enrichment of nervonic acid in Acer truncatum Bunge oil by combination of two-stage molecular distillation,one-stage urea complexation and five-stage solvent crystallization
1
作者 Yingxi Gao Jiayi Shi +4 位作者 Jie Wang Fan Zhang Shichao Tian Zhiyong Zhou Zhongqi Ren 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第7期61-71,共11页
Nervonic acid is the world’s first and only potent substance that can repair damaged nerve fibers and promote nerve cell regeneration with high nutritional value.The wide variety of fatty acids in plant oils and fats... Nervonic acid is the world’s first and only potent substance that can repair damaged nerve fibers and promote nerve cell regeneration with high nutritional value.The wide variety of fatty acids in plant oils and fats with similar structures makes the large-scale separation and purification of high-purity nervonic acid very difficult.A new combined process of molecular distillation,urea inclusion and solvent crystallization was established to prepare high-purity nervonic acid with the mixed fatty acids obtained after saponification and acidification of Acer truncatum Bunge oil as raw materials.First,according to the difference in the mean free path of fatty acids,molecular distillation was used to separate and remove C16 saturated fatty acid of palmitic acid and four C18-C20 fatty acids of stearic,oleic,linoleic,and linolenic acids.The content of C16-C20 fatty acids decreased from 72.92% to 19.22% after two-stage molecular distillation processes,in which the contents of saturated fatty acid of palmitic acid decreased to about 0.5%.Then,according to the difference in carbon chain length and saturation of fatty acid,the contents of C22-C24 saturated fatty acids of tetracosanoic and docosanoic acids decreased to 0.21% and 0.07% by urea inclusion with urea/free fatty acid preparation by saponification(SPOMFs)ratio as 0.6.In addition,all saturated fatty acids were basically separated.Finally,according to the difference in the solubility of fatty acids in solvents,the C18-C20 unsaturated fatty acids of oleic,linoleic,and linolenic acids and C22 unsaturated fatty acid of erucic acid were removed by solvent crystallization.The content of C18-C20 unsaturated fatty acids decreased to less than 5% with pentanol as the solvent after the first stage solvent crystallization.The content of erucic acid decreased to 3.47% with anhydrous ethanol as the solvent after the second to fifth stage solvent crystallization.The combined process of molecular distillation,urea inclusion and low temperature crystallization innovatively adopted an efficient,simple and easy-toindustrial solvent crystallization method to separate erucic and nervonic acids,obtaining nervonic acid with purity of 96.53% and final yield of 47.99%. 展开更多
关键词 Nervonic acid Acer truncatum Bunge Molecular distillation Urea complexation Solvent crystallization
下载PDF
A Systematic Review of Automated Classification for Simple and Complex Query SQL on NoSQL Database
2
作者 Nurhadi Rabiah Abdul Kadir +1 位作者 Ely Salwana Mat Surin Mahidur R.Sarker 《Computer Systems Science & Engineering》 2024年第6期1405-1435,共31页
A data lake(DL),abbreviated as DL,denotes a vast reservoir or repository of data.It accumulates substantial volumes of data and employs advanced analytics to correlate data from diverse origins containing various form... A data lake(DL),abbreviated as DL,denotes a vast reservoir or repository of data.It accumulates substantial volumes of data and employs advanced analytics to correlate data from diverse origins containing various forms of semi-structured,structured,and unstructured information.These systems use a flat architecture and run different types of data analytics.NoSQL databases are nontabular and store data in a different manner than the relational table.NoSQL databases come in various forms,including key-value pairs,documents,wide columns,and graphs,each based on its data model.They offer simpler scalability and generally outperform traditional relational databases.While NoSQL databases can store diverse data types,they lack full support for atomicity,consistency,isolation,and durability features found in relational databases.Consequently,employing machine learning approaches becomes necessary to categorize complex structured query language(SQL)queries.Results indicate that the most frequently used automatic classification technique in processing SQL queries on NoSQL databases is machine learning-based classification.Overall,this study provides an overview of the automatic classification techniques used in processing SQL queries on NoSQL databases.Understanding these techniques can aid in the development of effective and efficient NoSQL database applications. 展开更多
关键词 NoSQL database data lake machine learning acid complex query smart city
下载PDF
Effects of Oleanolic Acid on the Immune Complex Allergic Reaction and Inflammation
3
作者 周重楚 孙晓波 +3 位作者 刘威 高洪波 师海波 苗艳波 《Journal of Chinese Pharmaceutical Sciences》 CAS 1993年第1期69-79,共11页
When oleanolic acid (OA) was administered ig before and after sensitization on d 1 to d 5 and d 11 to d 17,it had no apparent effect on Arthus reaction.When it was administered at 48,24 and 1 h before challenge,howeve... When oleanolic acid (OA) was administered ig before and after sensitization on d 1 to d 5 and d 11 to d 17,it had no apparent effect on Arthus reaction.When it was administered at 48,24 and 1 h before challenge,however,Arthus reaction was significantly inhibited.OA showed markedly suppressive effects on reversible passive Arthus reaction and leukocyte migratory response.It could significantly stabilize erythrocyte membrane,inhibit the swelling of the rat's hind paw induced by in- jecting mycostatin,reduce the acid phosphatase content in the inflammatory exudate,suppress the syn- thesis or release of PGE,histamine,LTB4 and kinin,and the phlogistic action of PGE_2,histamine,5- HT and kinin.In addition,it could decrease the content of malonyldialdehyde (MDA) in hepatic tissue of alcohol-intoxicated mice,and increase the activity of catalase (CAT) in hepatic tissue of mice.OA had no apparent effect on the activity of super-oxide dismutase (SOD) in rat serum,on the content of immune complex in serum of rat with Arthus reaction,on the phagocytosis of monocytc-macrophage system,on the clearance of enzyme-containing immune complex by macrophage,or on the activity of total complement. 展开更多
关键词 Oleanolic acid Immune complex allergic reaction Anti-immune complex allergic reaction INFLAMMATION ANTI-INFLAMMATION
下载PDF
Cu(Ⅱ),Ni(Ⅱ)Complexation with Acid Alizarine Blue B in the Presence of Cetyltrimethylammonium Bromide
4
作者 沈荣 郜洪文 俞汉青 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第2期178-182,共5页
The coordination reactions of Cu(Ⅱ) and Ni(Ⅱ) with acid alizarine blue B (AABB) in the presence of cetyltrimethylammonium bromide (CTAB) micelle were investigated using the microsurface adsorptionspectral co... The coordination reactions of Cu(Ⅱ) and Ni(Ⅱ) with acid alizarine blue B (AABB) in the presence of cetyltrimethylammonium bromide (CTAB) micelle were investigated using the microsurface adsorptionspectral correction technique (MSASC). The aggregation of AABB on CTAB followed the Langmuir isothermal adsorption law. The enrichment of AABB on CTAB sensitized the complexation between Cu(Ⅱ) or Ni(Ⅱ)and AABB. The binding ratio of AABB to CTAB was 1:2.5, and monomeric aggregate, AABB2CTAB5, was formed with an adsorption constant of 5.95×10^5 at 20 ℃ or 2.48×10^5 at 40 ℃. In the ternary complexation, the ratio of AABB:Cu and AABB:Ni were 1:1 and 1:2.5, respectively. Two types of aggregates, Cu2.AABB2·CTAB80 and Ni5.AABB2.CTAB80, were formed. 展开更多
关键词 Microsurface adsorption-spectral correction technique Langmuir aggregation acid alizarine blue B Cetyltrimethylammonium bromide Ternary complex
下载PDF
Synthesis,Characterization and Antibacterial Properties of Rare Earth (Ce^(3+) ,Pr^(3+) ,Nd^(3+) ,Sm^(3+) ,Er^(3+) ) Complexes with L-Aspartic Acid and o-Phenanthroline 被引量:15
5
作者 郁慧 何其庄 +1 位作者 杨静 郑文捷 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第z2期4-8,共5页
Five novel ternary complexes of rare earth ions with L-Aspartic acid (Asp) and o-phenanthroline (Phen) were synthesized in ethanol aqueous solution. Their compositions were characterized by elemental analysis, molar c... Five novel ternary complexes of rare earth ions with L-Aspartic acid (Asp) and o-phenanthroline (Phen) were synthesized in ethanol aqueous solution. Their compositions were characterized by elemental analysis, molar conductance, FT-IR, Raman, UV-VIS and TG-DTA. The compositions of the complexes were confirmed to be: RE( Asp)3PhenCl3·3H2O (RE: Ce3+ , Pr3+ , Nd3+ , Sm3+ , Er3+ ). The antibacterial activity test shows that all these complexes exhibit excellent antibacterial ability against Escherichia coli, Staphylococcus aureus and Candida albicans. The antimicrobial spectrum of the complexes are broad. 展开更多
关键词 complexES O-PHENANTHROLINE L-Aspartic acid antibacterial activity rare earths
下载PDF
ATR-FTIR and XPS study on the structure of complexes formed upon the adsorption of simple organic acids on aluminum hydroxide 被引量:8
6
作者 GUAN Xiao-hong CHEN Guang-hao SHANG Chii 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第4期438-443,共6页
Information on the binding of organic ligands to metal (hydr)oxide surfaces is useful for understanding the adsorption behaviour of natural organic matter on metal (hydr)oxide. In this study, benzoate and salicyla... Information on the binding of organic ligands to metal (hydr)oxide surfaces is useful for understanding the adsorption behaviour of natural organic matter on metal (hydr)oxide. In this study, benzoate and salicylate were employed as the model organic ligands and aluminum hydroxide as the metal hydroxide. The attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra revealed that the ligands benzoate and salicylate do coordinate directly with the surface of hydrous aluminum hydroxide, thereby forming innersphere surface complexes. It is concluded that when the initial pH is acidic or neutral, monodentate and bridging complexes are to be formed between benzoate and aluminum hydroxide while bridging complexes predominate when the initial pH is alkalic. Monodentate and bridging complexes can be formed at pH 5 while precipitate and bridging complexes are formed at pH 7 when salicylate anions are adsorbed on aluminum hydroxide. The X-ray photoelectron (XP) spectra demonstrated the variation of C 1 s binding energy in the salicyate and phenolic groups before and after adsorption. It implied that the benzoate ligands are adsorbed through the complexation between carboxylate moieties and the aluminum hydroxide surface, while both carboxylate group and phenolic group are involved in the complexation reaction when salicylate is adsorbed onto aluminum hydroxide. The information offered by the XPS confirmed the findings obtained with ATR-FTIR. 展开更多
关键词 ADSORPTION aluminum hydroxide benzoic acid complexATION natural organic matter salicylic acid
下载PDF
A Series of Mononuclear Complexes Constructed from Transition Metals and Amino Acid Derived Ligands: Syntheses, Structures and Photoluminescence 被引量:6
7
作者 李新发 曹荣 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第11期1439-1447,共9页
Eight neutral mononuclear complexes constructed from transition metals (M = Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Cd(Ⅱ)) and ligands N-(2-pyridylmethyl)-L-phenylalanine (L-Hpmpa) and N-(2-pyridylmethyl)-L... Eight neutral mononuclear complexes constructed from transition metals (M = Co(Ⅱ), Ni(Ⅱ), Cu(Ⅱ), Zn(Ⅱ), Cd(Ⅱ)) and ligands N-(2-pyridylmethyl)-L-phenylalanine (L-Hpmpa) and N-(2-pyridylmethyl)-L-tyrosine (L-Hpmtyr) have been synthesized by both hydrothermal and conventional room temperature reactions. Four of them have been structurally characterized by single-crystal X-ray diffractions. They are: [Co(L-pmpa)2·2H2O] 1, [Ni(L-pmpa)2·2H2O] 2, [Cu(L-pmpa)2·2H2O] 3 and [Cu(L-pmtyr)2·2H2O] 4. Single-crystal X-ray analysis, IR and elemental analysis revealed that complexes 1, 2 and 3 are isostructural. Powder X-ray diffraction, IR and elemental analysis revealed that complexes 4, 5 (Zn[L-pmtyr]2·2H2O), 6 (Cd[L-pmtyr]2·2H2O), 7 (Co[L-pmtyr]2·2H2O) and 8 (Ni[L-pmtyr]2·2H2O) are isostructural. The photoluminescence properties of L-Hpmtyr ligand, compounds 5 and 6 were also investigated. 展开更多
关键词 amino acid zinc complex cadmium complex PHOTOLUMINESCENCE
下载PDF
Synthesis,Characterization and Fluorescence Properties of Europium,Terbium Complexes with Biphenyl-4-Carboxylic Acid and o-Phenanthroline 被引量:4
8
作者 赵永亮 赵凤英 +1 位作者 李强 高德青 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第z2期18-22,共5页
Two series of solid complexes of europium and terbium with biphenyl 4-carboxylic acid and phen were synthesized and characterized in this report. Their elemental analysis, molar conductivities and TG-DTA studies indic... Two series of solid complexes of europium and terbium with biphenyl 4-carboxylic acid and phen were synthesized and characterized in this report. Their elemental analysis, molar conductivities and TG-DTA studies indicate that the complexes have the composition of Eu(phen)L3·1/2H2O, Eu0.5RE0.5(phen) L3·1/2H2O; Tb (phen) L3·H2O and Tb0.5 RE0.5(Phen)L3·1/2H2O. (RE = Y3+, La3+ and Gd3+; L = biphenyl 4-carboxylic acid; phen = o-Phenanthroline). The studies of their IR, UV 1H NMR and molar conductivities demonstrate that biphenyl 4-carboylic acid is bounded with RE (III ) ion. Rare earth ions coordinate with two nitrogen atoms of phen molecules directly in these rare earth complexes. The fluorescence spectra and fluorescence lifetimes of the rare earth complexes show that the fluorescent intensity and lifetime of a series of europium complexes are longer than those of the series of terbium complexes as having the some ligands. There are better fluorescent intensity and lifetime of hetero-nuclear rare earth complexes than homo-nuclear rare earth complexes for europium complexes. The fluorescence emission intensity of Eu3 + is raised by inert fluorescent rare earth ions (Y3+ , Gd3+ and La3+ ), but in Tb3+ hetero-nuclear rare earth complexes the intensity of Tb3+ ions are quenched by the inert fluorescent rare earth ions. 展开更多
关键词 biphenyl 4-carboxlic acid O-PHENANTHROLINE europium complex terbium complex rare earths
下载PDF
An investigation of oxygen pressure acid leaching of Gacun complex Cu-Pb bulk concentrate 被引量:6
9
作者 Xu, Bin Zhong, Hong Jiang, Tao 《Rare Metals》 SCIE EI CAS CSCD 2012年第1期96-101,共6页
The treatment of the Gacun complex Cu-Pb bulk concentrate with high Zn,Ag,etc.,by oxygen pressure acid leaching was studied.The pri-mary copper and leadminerals in the concentrate are tetrahedrite and galena.The treat... The treatment of the Gacun complex Cu-Pb bulk concentrate with high Zn,Ag,etc.,by oxygen pressure acid leaching was studied.The pri-mary copper and leadminerals in the concentrate are tetrahedrite and galena.The treatment of tetrahedrite was rarely studied,and most of silver occurred in themineral too.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Under these parameters,the result of pilot scale test showed that the leaching percentages of copper and zinc were separately as high as 98.9 wt.% and 94.9 wt.%,while lead and silver were transformed into sulfate and sulfide precipitations,respectively.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by carbonate transformation-silicofluoric acid leaching and thiourea leaching. 展开更多
关键词 nonferrous metallurgy synthetic reclaiming oxygen pressure acid leaching complex Cu-Pb bulk concentrate TETRAHEDRITE
下载PDF
Preparation of Ternary Lanthanide Complexes with Unsaturated Acid and 1,10-Phenanthroline, and Their Anti-Inflammatory Action 被引量:4
10
作者 刘鸿 张惠珍 +1 位作者 曾伟 曾正志 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第S1期46-50,共5页
Four ternary lanthanide complexes with unsaturated acid and 1,10-phenanthroline are prepared in methanol and characterized by elemental analysis, molar conductance, UV, IR, (()~1H) NMR and XPS. The results from this p... Four ternary lanthanide complexes with unsaturated acid and 1,10-phenanthroline are prepared in methanol and characterized by elemental analysis, molar conductance, UV, IR, (()~1H) NMR and XPS. The results from this paper show that the complexes Ln(phen)(SA)_3·2H_2O or Ln(phen)(CA)_3·H_2O (Ln=Ce(Ⅲ), Sm(Ⅲ) and Eu(Ⅲ), (phen=1,10-)phenanthroline, SA=Sorbate and CA=Cinnamate) has better anti-inflammatory effect than cerium nitrate and their gremores are steadier than cerium nitrate gremor. And there is a kind of medicament which can replace the cerium nitrate gremor completely in treating burn. 展开更多
关键词 unsaturated acid 1 10-PHENANTHROLINE ternary lanthanide complexes ANTI-INFLAMMATORY BURN rare earths
下载PDF
Crystal Structure and Luminescence Property of Lanthanide Complexes with 2-Fluorobenzoic Acid and 2,2′-Bipyridine 被引量:4
11
作者 李夏 张卓勇 宋海斌 《Journal of Rare Earths》 SCIE EI CAS CSCD 2005年第5期615-618,共4页
The two compounds of [Ln(2-FBA)3·2,2'-bpy ]2(2-FBA = 2-fluorobenzoato, 2,2'-bpy = 2,2'-bipyridine, Ln = Eu(1 ), Dy(2)) were synthesized and their structures were determined by X-ray diffraction method.... The two compounds of [Ln(2-FBA)3·2,2'-bpy ]2(2-FBA = 2-fluorobenzoato, 2,2'-bpy = 2,2'-bipyridine, Ln = Eu(1 ), Dy(2)) were synthesized and their structures were determined by X-ray diffraction method. Crystallized complexes 1 and 2 are isomorphous, monoelinie system with P21/n space group. The two complexes are binuclear molecule with an inversion center. The two lanthanide ions are linked by four bridged 2-FBA ligands and each lanthanide ion is further bonded to one chelated bidentate 2-FBA ligand and one 2,2'-bipyridine molecule. The coordination number of metal ion is eight. The europium complex exhibits strong red fluorescence. ^5D0→^7Fj(j = 1 - 4) transition emission of Eu^3+ ion was observed. 展开更多
关键词 lanthanide complexes 2-fluorobenzoic acid crystal structure rare earths
下载PDF
Complex behaviour of trivalent rare earth elements by humic acids 被引量:4
12
作者 Geng An chaoResearch Institute of Environmental Engineering,Fushun Petroleum Institute,Liaoning 113001,ChinaZhang Shen Institute of Geography,Chinese Academy of Sciences,Beijing 100101,ChinaHarald Hфiland Department of Chemistry,Univers 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1998年第3期47-53,共7页
The complexation behaviours of trivalent rare earth elements (La, Ce, Ho and Yb) by two types of humic acids were investigated under a specified set of conditions. Humic acids show quite different complexation capaci... The complexation behaviours of trivalent rare earth elements (La, Ce, Ho and Yb) by two types of humic acids were investigated under a specified set of conditions. Humic acids show quite different complexation capacities an conditional formation constants with the REEs. Apparently there are two types of binding sites in the functional groups of humic acid, in which the first binding sites have stronger ability than the second. Cerium shows the largest complexation capacities and highest formation constants among the four REEs with two humic acids, this anomaly may be relative to the distribution pattern of the REEs in seawater. The experimental results were comparable to the values of other metals reported and provided the basic data for environmental geochemistry of rare earth elements. 展开更多
关键词 complex behaviour rare earth elements humic acid.
下载PDF
Investigation on the syntheses and structures of Y^(Ⅲ) complexes with ami-nopolycarboxylic acids (Ⅳ) 被引量:3
13
作者 WANG Jun, ZHANG Xiangdong, LING Xiao, JIA Weiguo, and FAN DaminDepartment of Chemistry, Liaoning University, Shenyang, 110036, China 《Rare Metals》 SCIE EI CAS CSCD 2002年第2期106-112,共7页
This paper deals with the structure of the Y^iii complex withaminopolycarboxylic acids, synthesis and struc- tural determinationof the complex (NH_4)[Y^III(edta)(H_2O)_3] ·3 H_2O (edta =ethylenediaminetetraacetic... This paper deals with the structure of the Y^iii complex withaminopolycarboxylic acids, synthesis and struc- tural determinationof the complex (NH_4)[Y^III(edta)(H_2O)_3] ·3 H_2O (edta =ethylenediaminetetraacetic acid). The crystal and molecularstructures of the (NH_4)[Y^III(edta)(H_2O)_3] ·3 H_2O complex havebeen determined by single-crystal X-ray structure analysis. Thecrystal of the complex (NH_4)[Y^III(edta)(H_2O)_3] ·3 H_2O belongsto orthorhombic crystal system and fdd2 space group. 展开更多
关键词 Y^III aminopolycarboxylic acids complex structure
下载PDF
Solvothermal Syntheses, Crystal Structures, Thermal Stability and Quantum Chemistry of Dinuclear Trialkyltin Complexes Constructed by Camphoric Acid 被引量:3
14
作者 庾江喜 邝代治 +3 位作者 冯泳兰 朱小明 蒋伍玖 张复兴 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2014年第10期1521-1526,共6页
Two dinuclear organotin complexes C8H14(CO2SnCy3)2(1)(Cy = cyclohexyl group) and C8H14[CO2Sn(CH2CMe2Ph)3]2(2) were synthesized by the reactions of camphoric acid with tricyclohexyltin hydroxide and bis[tri(... Two dinuclear organotin complexes C8H14(CO2SnCy3)2(1)(Cy = cyclohexyl group) and C8H14[CO2Sn(CH2CMe2Ph)3]2(2) were synthesized by the reactions of camphoric acid with tricyclohexyltin hydroxide and bis[tri(2-methyl-2-phenyl)propyltin] oxide under solvothermal conditions, and these complexes were characterized by infrared spectra, elemental analyses, and H NMR spectra. The crystal of 1 belongs to the monoclinic system, space group P21/c with a = 1.83478(19), b = 1.52707(18), c = 1.9849(2) nm, β = 122.515(7)°, Z = 4, V = 4.6896(9) nm^3, Dc = 1.324 g/cm^3, μ(MoKα) = 1.103 mm^-1, F(000) = 1952, R = 0.0697 and wR = 0.2040. In addition, thermal stability and quantum chemical calculation of 1 were also studied. 展开更多
关键词 trialkyltin complex camphoric acid solvothermal synthesis structure quantum chemistry
下载PDF
Fluorescence of complexes of EuⅢwith aromatic carboxylic acid-1,10-phenanthroline 被引量:3
15
作者 舒万艮 周忠诚 牛聪伟 《中国有色金属学会会刊:英文版》 CSCD 2001年第5期806-809,共4页
The 1,10 phenan throline aromatic carboxylic acid(benzoic acid and o phthalic acid) binary and ternary complexes of europium were synthesized.The fluorescence and FT IR spectroscopy,elemental analysis,UV spectroscopic... The 1,10 phenan throline aromatic carboxylic acid(benzoic acid and o phthalic acid) binary and ternary complexes of europium were synthesized.The fluorescence and FT IR spectroscopy,elemental analysis,UV spectroscopic studies on these complexes were also performed.These complexes can emit strong red fluorescence of Eu? excited by UV light.At the same excited wavelength,the fluorescence spectra of the complexes were also studied.The results indicated that the fluorescence intensities of ternary complexes are stronger than that of binary complexes.The reason is that phenanthroline has higher electron density and higher orbit scope in the conjugated system and consequently an easier energy transfer to the europium ion,which makes the fluorescence intensity of ternary complexes be stronger than that of binary complexes. 展开更多
关键词 complexes of europium o phthalic acid benzoic acid 1 10 phenanthroline fluorescence spectra
下载PDF
Syntheses and Crystal Structures of Three Ag(Ⅰ) Complexes with Chloro-phenylacetic Acid and Nitrogen Heterocyclic Ligand 被引量:4
16
作者 郝晓敏 谷长生 +3 位作者 纪丽丽 胡世伟 李泳 宋文东 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第9期1362-1370,共9页
Three new coordination polymers {[Ag2(2,4-DCPA)(4,4"-bipy)2(NO3)].(H20)}, (1), [Ag(2,4-DCPA)(bpp)], (2) and {[Ag(4-DCPA)(bpp)]'(H20)}, (3), were synthesized by evaporation methods using 2,4-d... Three new coordination polymers {[Ag2(2,4-DCPA)(4,4"-bipy)2(NO3)].(H20)}, (1), [Ag(2,4-DCPA)(bpp)], (2) and {[Ag(4-DCPA)(bpp)]'(H20)}, (3), were synthesized by evaporation methods using 2,4-dichlorophenylacetic acid (2,4-DCPA), 4-chlorophenylacetic acid (4-DCPA), 4,4"-dipyridyl (4,4"-bipy), 1,3-bis(4-pyridyl)propane(bpp) and AgNO3. Compound 1 crystallizes in monoclinic, space group P21/c with a = 10.035(2), b = 17.796(3), c = 16.448(2) A, fl = 104.086(2)°, V= 2705.9(2) A3, Dc = 1.893 g/cm-3, C28H23C12NsO6Ag2, Mr = 812.15, F(000) = 1608,μ(MoKot) = 1.615 mm-1, Z = 4, R = 0.0310, wR = 0.0832 for 4357 observed reflections (I 〉 20(/)), and R = 0.0362, wR = 0.0873 for all data. Compound 2 crystallizes in monoclinic, space group P21/c with a = 9.840(2), b = 24.971(5), c = 9.3301(2)°, fl = 117.504(2)°, V= 2033.5(7) A3, Dc = 1.666 g/cm3, C2tH19C12N202Ag, Mr = 510.15, F(000) = 1024,/I(MoKa) = 1.273 mml, Z= 4, R = 0.0315 and wR = 0.0680 for 2853 observed reflections (1 〉 20(/)) and R = 0.0454, wR = 0.0736 for all data. Compound 3 crystallizes in monoclinic, space group P21/n with a = 15.472(4), b = 9.000(2), c = 16.262(4) A, fl = 112.049(4)°, V = 2099.0(8) A3, Dc = 1.562 g/cm-3, C2H22C1N203Ag, Mr = 493.73, F(000) = 1000, μ(MoKa) = 1.111 mm-1, Z = 4, R = 0.0296, wR = 0.0821 for 3059 observed reflections (I 〉 2δ-(I)), and R = 0.0398, wR = 0.0986 for all data. The complexes were characterized by elemental analysis, FT-IR, thermogravimetrie analysis (TGA) and X-ray single-crystal structure analysis. Fluorescence properties of complex 3 and PXRD of 1 and 2 have been studied. As a result, in complex 1, the Ag(I) ion is surrounded by two nitrogen atoms from two bipy ligands to form an infinite chain, and adjacent Ag-bipy chains produce "'rungs" of a ladder by silver ions contact. And in complexes 2 and 3, the two-dimensional ,β-sheet like layers are obtained by Ag……Ag interactions. 展开更多
关键词 silver complex chloro-phenylacetic acid crystal structure
下载PDF
Hydrothermal Synthesis and Crystal Structure of a New One-dimensional Nickel(Ⅱ) Complex with 2-Pyridinecarboxyic Acid and 4,4′-Bipyridine Ligands 被引量:4
17
作者 李秀梅 牛艳玲 +3 位作者 王庆伟 刘博 赵霞 李丹 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2009年第3期321-324,共4页
A new metal-organic coordination polymer [Ni[(2-pya)2(4,4′-bipy)]n·6nH2O (2-pya = 2-pyridinecarboxylic acid, 4,4′-bipy = 4,4′-pyridine) 1 has been hydrothermally synthesized and structurally characterize... A new metal-organic coordination polymer [Ni[(2-pya)2(4,4′-bipy)]n·6nH2O (2-pya = 2-pyridinecarboxylic acid, 4,4′-bipy = 4,4′-pyridine) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The complex crystallizes in tetragonal, space group I4 1/α with a = b = 22.5642(19), c = 10.7118(18) A, V = 5453.8(11) A^3, C22H28N4NiO10, Mr= 567.19, Dc = 1.382 g/cm^3, μ(MoKα) = 0.769 mm^-1, F(000) =2368, Z = 8, the final R = 0.0572 and wR = 0.1254 for 1401 observed reflections (I 〉 2σ(I)). It exhibits a one-dimensional chain-like structure by mixed ligands of 2-pyridinedicarboxylic acid and 4,4′-pyridine. 展开更多
关键词 2-pyridinecarboxylic acid nickel(Ⅱ) complex crystal structure
下载PDF
Study on the Structure of Supramolecular Inclusion Complex of β-Cyclodextrin with Retinoic Acid 被引量:3
18
作者 Yan Ling ZHANG Wei Sheng LIU +2 位作者 Yang LI Xue Yi MA Yao Zu CHEN 《Chinese Chemical Letters》 SCIE CAS CSCD 2001年第4期317-320,共4页
Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, F... Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-guest. 展开更多
关键词 Retinoic acid Β-CYCLODEXTRIN Inclusion complex structure
下载PDF
Synthesis and Crystal Structure of a New Copper(II) Complex with 4-Cyanobenzoic Acid 被引量:6
19
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
Synthesis, Characterization and Fluorescence of Terbium(Ⅲ) Complexes with Phenylglyoxylic Acid and 2,2-Dipyridine, 1,10-Phenanthroline, Triphenyl Phosphine Oxide 被引量:2
20
作者 张彦辉 颜剑波 +3 位作者 裴娟 耿啸天 王云友 孙波 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第2期146-149,共4页
Three new complexes TbL3dipy (H2O)2, TbL3phen (H2O) 2 and TbL2 (TPPO) 2NO3 were synthesized (L = phenylglyoxylate ion, dipy = 2, 2-dipyridine, phen = 1,10-phenanthmline, TPPO = Triphenyl phosphine oxide). Elem... Three new complexes TbL3dipy (H2O)2, TbL3phen (H2O) 2 and TbL2 (TPPO) 2NO3 were synthesized (L = phenylglyoxylate ion, dipy = 2, 2-dipyridine, phen = 1,10-phenanthmline, TPPO = Triphenyl phosphine oxide). Elemental analysis, conductivity, IR spectra, and ^1HNMR spectra studies were performed. IR spectra indicate that the carboxylate ion of phenylglyoxylate is coordinated to the Tb(Ⅲ) ion as an unidentate ligand. In ^1HNMR, the signals of different hydrogens in phenylglyoxylate ion shift upfield. The excitation and emission spectra of the three solid complexes were recorded at morn temperature, in which the optimum excitation wavelengths are, 361.0, 359.0 and 367.0 nm for these three complexes, respectively. Four emission bands due to the ^5D4-^7Fj(j = 6, 5, 4, 3) transitions were observed for TbL3dipy(H2O)2(489.0, 545.0, 584.0, 620.0 nm) and TbL3phen(H2O)2(490.0, 544.0, 583.0, 620.0 nm). Under the same conditions, only one emission band due to the ^5D4-^7F5 transition was observed for the complex TbL2(TPPO)2NO3. The emission intensity of TbL3dipy(H2O)2 is the strongest among the three complexes. 展开更多
关键词 TERBIUM complexES phenylglyoxylic acid IR spectra fluorescence spectra rare earths
下载PDF
上一页 1 2 204 下一页 到第
使用帮助 返回顶部