学科分类
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269 个结果
  • 简介:介绍了新型多功能稳定剂JAST的合成路线,对该产品的光稳定性和抗氧性进行了讨论。

  • 标签: JAST500 紫外线吸收剂 抗氧剂
  • 简介:Highlyselectivedimerizationofα-methylstyrene(AMS)waseffectedusingaBroenstedacidicionicliquid,[Hmim]^+BF4^-,assolventaswellascatalyst,providingtheindustrialhigh-valueolefin,2,4-diphenyl-4-methyl-1-pentene(1-PT).Thedesireddimer1-PTcouldbeobtainedin90%yieldat96%conversioninthedimerizationofAMSunderoptimizedconditions.Featuresoftheprocedureincludeuseofreadilyavailableionicliquid-catalyst,exclusionofvolatileorganicsolvents,higherselectivityandefficiencyfor1-PT.

  • 标签: 2 4-联苯-4-甲基-l-戊烯 ^+BF4^- 离子性液体 化学结构 催化剂
  • 简介:AnefficientroutetoprepareL-glucoseandL-galactoseisdescribed.TheL-sugarsareachievedbyusingthestrategyofswitchingthefunctionalgroupsatC1andC5ofD-glucoseandD-mannose.TheoxidationandreductionofthesilylenoletheratC1andthelead(IV)tetraacetatemediatedoxidativedecarboxylationatC5arethekeysteps.L-GlucoseandL-galactosearepreparedinaconvenientandinexpensiveway.

  • 标签: 半乳糖衍生物 D-葡萄糖 左旋 合成 D-甘露糖 甲硅烷基
  • 简介:[1]BASFUSP4479906[2]BASFBP1443541[3]BASFDE3618265[4]WangL.,WuZ.,ChinaLeather,26(8),11,(1997)[5]YuanL.,DinY.,ChineseChemistryBulletin,(2),19(1988)[6]KurokiH.,ChemistryofDyeingTheory(ChineseTranslation),TextileIndustryPress,Beijing,89(1982)[7]WangS.,LiP.,WuZ.DyestuffIndustry(Chinese),34(4),1,(1997)[8]Tian,Y.,Wu,Z.,Wang,G.,Zhang,S.J.ChineseChem.Eng.,46,156(1995)[9]Tian,Y.,Wang,G.,Wu,Z.,J.ChineseChem.Eng.,47,75(1996)[10]Lycka,A.,DyesandPigment,32,11(1996)[11]Griffith,J.,ColourandConstitutionofOrganicMolecules,AcademicPress,London,191(1976)

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  • 简介:Poly(4-vinylpyridine)supportednanoparticleofcopper(Ⅰ)iodideisreportedasagreenandrecyclablecatalystfortheregioselectivesynthesisof1,4-disubstituted-1H-1,2,3-triazolesfrombenzylhalides,sodiumazideandterminalalkynesinwater.Thiscatalystcanberecoveredbysimplefiltrationandrecycledupto8consecutiverunswithoutanylossofitsefficiency.

  • 标签: 区域选择性合成 铜纳米粒子 乙烯基吡啶 催化剂 二取代 碘化
  • 简介:Sixnewopticallyactivepoly(amide-imide)s(5a-f)weresynthesizedthroughthedirectpolycondensationreactionofN,N'-(4,4'-diphthaloyl)-bis-L-leucine(3)withsixhydantoinderivatives(4a-f).Triphenylphosphite(TPP)/pyridineinthepresenceofcalciumchloride(CaCl_2)andN-methyl-2-pyrrolidone(NMP)weresuccessfullyappliedfordirectpolycondensation.Thepolycondensationreactionsproduceaseriesofnewpoly(amide-imide)s(5a-f)inhighyields,andinherentviscositybetween0.42and0.55dL/g.Theresultingpoly(amide-imide)s(5a-f)werecharacterizedbyelementalanalysis,viscositymeasurements,thermalgravimetricanalysis(TGAandDTG),solubilitytestandFT-IRspectroscopy.

  • 标签: 光学活性 反应合成 脲衍生物 亮氨酸 亚胺 酰胺
  • 简介:NineteenL-N-2-hydroxyethylaminoacidsandL-N,N-bis(2-hydroxyethyl)aminoacidswerepreparedfromthereactionofchlorohydrinwithL-alanine,L-valine,L-leucine,L-isoleucine,L-phenylalanine,L-serine,L-thrcunine,L-glutamicacid,L-asparticacidandglycine.L-N,N,N’,N’-tetra(2-hydroxyethyl)cystinewaspreparedbythereactionofL-cystinewithchlorohydrin.

  • 标签: hydroxyethyl PHENYLALANINE LEUCINE GLYCINE tetra solubility
  • 简介:Dibromobiphenylreactedwithcynomethylanioninammoniaunderirradiationtoformnucleophilicbis-substitutedproductinhighyieldwithoutsubstantialmonosubstitutedproduct.Quantumyieldsfortheformationsofbis-andmonosubstitutedproductswerefoundtobe85.6and2.3×10-6respectively,whilethecorrespondingpseudo-first-orderrateswere6.9×10-3and5.2×10-10mol.L-1.S-1.Blockupthepossibleelectrontransferof4-brome-4’-cyanomethylbiphenylylradicalanionto4-cyanometbyl-biphenylylradicalandbromineion.

  • 标签: PHOTOCHEMISTRY SRN1 REACTION electron TRANSFER dibromobiphenyl.
  • 简介:Ahomologousseriesof4’-methylphenyl4"-[(4-alkoxy-2,3,5,6-tetrafluorophenyl)ethynyl]-benzoateshavebeensynthesized.Polarizingmicroscopictexturalobservationshowsthatsuchcompoundsexhibitenantiotropicnematicphase.

  • 标签: Liquid crystal 1 4-tetrafluorophenylene SYNTHESIS NEMATIC
  • 简介:Thesynthesisofopen-fiameworkmetalphosphateshasbeenasubjectofintenseresearchowingtotheirinterestingstructuralchemistryandpotentialapplicationsasionexchangers,catalystsandadsorbents.Alargenumberofthesematerialsaresynthesizedinthepresenceoforganicaminesasstructure-directingagents.Recently,manyresearchactivitieshavefocusedonthesynthesisofinorganic-organichybridframeworks.Ascomparedwithinorganicligands,theadvantageofusingorganicmultidentateligandsistheefficacyofrationaldesignofcrystallinesolidsthroughtheircoordinatingpropensitiesandgeometries.

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  • 简介:Thesynthesisandphasebehaviorofaseriesof4’-alkyloxy-4-hydroxybiphenylswerediscribed.Theeffectsofreactionconditionsontheyieldsofproductswereinvestigated.Thecharacterizationsofthermotropicliquidcrystallineproductsforthetypeandthermalpropertiesarediscussedthroughtheuseofdifferentialscanningcalorimetry,polarizingmicroscopy.

  • 标签: crystalline ATTRACTIVE spectrometer PHOTOGRAPH CALORIMETRY melting
  • 简介:Reactionsofthe6-hydroxy-thiopyrano[3,4-c]pyridine-5-carbonitrilederivative1withα-halo-carbonylcompoundsgavetheortho-substitutedintermediates2a-cwhichwereconvertedintofuro[2,3-b]thiopyrano[4,3-d]pyridines3a-cbyfusionofafuranmoietyunderbasicconditions.Furthercyclizationof3a-cledtoafusionofapyrimidinering,yieldingthetetracyclicproducts6,7and8.Inaddition,condensationof6withvariousaromaticaldehydesaffordedthecorrespondingimines9a,b.Mannichreactionof7gaveproducts10a,b.

  • 标签: Synthesis AROMATIC ALDEHYDES products MANNICH reaction
  • 简介:3,5,6,8-Tetrahydro-4H-thiopyrano[4′,3′:4,5]thieno[2,3-d]pyrimidin-4-ones(7)weresynthesizedviathebasecatalyticreactionsofaminesorphenolswithcarbodiimides(5),whichwereobtainedfromtheaza-Wittigreactionsofiminophosphoranes(4)witharomaticisocyanates.

  • 标签: 反应合成 膦亚胺 四氢 噻吩 嘧啶 碳二亚胺
  • 简介:ByusingOH-terminatedpolyaryletherdendrimerandN-Fmoc-glycineasrawmaterials,thedendriticpolyarylether2-aminoacetate(G3-NH2)wassynthesizedviatwostepreactions.G3-NH2asamacroinitiatorforthering-openingpolymerizationofγ-benzylL-glutamateN-carboxyanhydridewasinvestigated.Itisfoundthattheresultingcopolymerspossessedrelativelyhighmolecularweightandnarrowmolecularweightdistribution(1.12

  • 标签: 开环聚合反应 γ-苯甲基L-谷氨酸酯N-羧基酐 多肽 枝晶
  • 简介:ConformationofL-lysineinaqueoussolutionwasinvestigatedbylanthanideshiftprobes(Dy,Ho,Er,TmandYb).Reilley’smethodwasemployedtoseparatethecontactanddipolarcom-ponentsofthe13Cparamagneticshifts.ThisstudyrevealsthatCαshifthasthelargestcontactcon-tributionwhiletheothercarbonshiftsaredominatedbythedipolarcontribution.TheaverageoverallconformationofL-lysineinaqueoussolutionisextendedwiththemolecularbackboneintransform.Inthecomplex,lanthanideioncoordinatestothecarboxylgroupwithLn—Obondlength2.2/nandthewholeligandislocatedoutsidethezero-dipolarshiftconeofthelanthanideion.Theelectronicspindensitydistributionontheligandnucleishowsthatthespinpolarizationisthepredominantmech-anismofthecontactinteractionfornucleiincloseproximitytotheboundlanthanideion.

  • 标签: LANTHANIDE probes LYSINE PARAMAGNETIC PROXIMITY coordinates
  • 简介:ThesolidcomplexesofCr(AA)2Cl3·nH2OofCrCl3withL-α-aminoacids(AA=Val,Len,Thr,Met,Arg,Phe,TryandHis)havebeenpreparedin95?EtOHmedium,andcharacterizedstructurallybyelementalanalysis,chemicalanalysis,IRspectraandTG-DTG.Theconstant-volumecombustionenergiesofthecomplexeshavebeendetermimedbyRBC-Ⅱtyperotating-bombcalorimeter.Thestandardenthalpiesofformationofthecomplexeshavebeencalculatedaswell,hwichare(-2543.16±3.71)(Val),(-2561.32±4.06)(Leu),(-2284.02±2.95)(Thr),(-1418.77±4.60)(Met(,(-3218.91±4.67)(Arg),(-2643.90±5.02)(Phe),(-1707.18±3.23)(Try)and(-2838.05±3.45)(His)kJ/mol,respectively.

  • 标签: 氯化铬 固体配合物 结构表征 热力学
  • 简介:本文通过电化学测量(循环伏安法)和量子化学计算(CNDO/2法)对几种原子簇化合物[(MoS4)2FeL]3-(其中配位体L为O2CH3CN,O2,O)的氧化还原活性进行了研究.实验测量与理论计算所得结果相符.研究结果表明这几种阴离子的还原皆为不可逆的单电子转移过程.它们接受电子的能力按如下次序递增:[(MoS4)2FeO2CH3CN]3-<[(MoS4)2FeO2]3-<[(MoS4)2FeO]3-

  • 标签: 氧化还原活性 Mo-Fe-S MoS4 eL 原子簇 单电子转移