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500 个结果
  • 简介:Cobaltandnickelcomplexes(1a-1dand2a-2d,respectively)supportedby2-imidate-pyridineligandsweresynthesizedandusedfor1,3-butadienepolymerization.ThecomplexeswerecharacterizedbyIRandelementanalysis,andcomplex1awasfurthercharacterizedbysingle-crystalX-raydiffraction.Thesolidstatestructureofcomplex1adisplayedadistortedtetrahedralgeometry.Uponactivationwithethylaluminumsesquichloride(EASC),allthecomplexesshowedhighactivitiestoward1,3-butadienepolymerization.Thecobaltcomplexesproducedpolymerswithhighcis-1,4contentsandhighmolecularweights,whilethenickelcomplexesdisplayedlowcis-1,4selectivityandtheresultingpolymershadlowmolecularweights.Thecatalyticactivitiesofthecomplexeshighlydependedontheligandstructure.Withtheincrementofpolymerizationtemperature,thecis-1,4contentandthemolecularweightoftheresultingpolymerdecreased.

  • 标签: 1 3-BUTADIENE Late-transition metal Cis-1 4-polybutadiene Pyridine-2-imidate
  • 简介:Thecrystalstructureof[Ni(TAAB)(py)2](BF4)2,whereTAABisthetetradentatemacrocyclicligandtetrabenzo[b,f,j,n][1,5,9,13]tetraazacyclohexadecine,hasbeendeterminedfromX-raydiffractionanalysis.Thecrys.taibeiongstomonoclinic,spacegroupP21/nwithcellparameters

  • 标签: MONOCLINIC shaped BRIDGED PYRIDINE BENZALDEHYDE editorial
  • 简介:Novelpyrimidinenucleoside-3,5-dicyanopyridinehybrids(4)orpyridineattachedacylureas(5)wereselectivelyandefficientlypreparedfromthereactionof2'-deoxyuridin-5-yl-methylenemalononitrile(1),malononitrile(2)andthiophenol(3)orfromanunexpecteduracilring-openingandpyridinering-formingsequenceviathereactionof1and3.Itisthefirsttimesuchasequencehaseverbeenreported.

  • 标签: 嘧啶核苷 尿嘧啶 吡啶 序列 环形 环和
  • 简介:Thegeometricalstructuresof2-(2-hydroxyphenyl)pyridine(PP)anditsprotonationstateswereoptimizedbymeansoftheB3LYP/6-31G(d)method.Foralltheselectedsystems,theexistenceofH-bondisinfavorofthestabilityofthesystems.Onthebasisoftheoptimizedgeometricalstructures,theirelectronicspectrumpropertieswerestudiedbytime-dependentdensityfunctionaltheory(TD-DFT)methosdviaahybridfunctionofB3LYPand6-31G(d)basisset.TheTD-DFTcalculationresultpredictstheabsorptionspectrumofPPat324nm(3.82eV),whichisinverygoodagreementwiththeexperimentalvalueof322nm(3.85eV)determinedinsolventchloroform.TheabsorptionspectraofthetwoprotonationstatesbothexertaredshiftinvariouspHmedia.

  • 标签: 理论研究 电子光谱 密度 2-(2-羟苯基)嘧啶 光谱性质
  • 简介:ANOVELREDUCTIVETETRAALLYLATIONOFPYRIDINE¥XianMouZENG;JiaQiang;CAIandYiJianGU(DalianinstituteofChemicalPhysics,AcademiaSinica1...

  • 标签:
  • 简介:Aseriesofcopper(Ⅱ)complexeswithpyridineN-oxide-2-ylmethylidened-ithiocarbazatesasligandsweresynthesizedandcharacterizedbyIRspectra,electronicspectraandmagneticmomentsmeasurementatroomtemperature.Variabletemperaturemagneticsusceptibilites(3-300K)offourcomplexsweremeasuredandfittedwiththeBleaney-Bowersdimerequationbyconsideringthemagneticinteractionbetweenmolecules.Thefittingresultsshowtheexistenceofintramolecularferromagneticinteractionsandintermolecu-laranti-ferromagneticinteractionsinthesecopper(Ⅱ)complexes.

  • 标签: PYRIDINE N-oxide-2-ylmethylidenedithiocarbazate Copper(Ⅱ) complex MAGNETIC SUSCEPTIBILITY
  • 简介:Inthiswork,DSCandSEMstudiesindicatethation-ligandinteractioncanbeutilizedtoenhancetheinteractionofpoly(styrene-block-2-vinylpyridine)[P(S-b-2VP)]andpolyethylenebasedionomer(Surlyn).Thecompatibilityforthisblendingsystemcanbeimprovedbythisspecialinteractionand20/80wtistheoptimumblendingcompositionwithgoodcompatibility.FTIRresultsfurthercertifythatstronginteractionsexistintheblendingsystem.

  • 标签: 聚(苯乙烯-B-2-乙烯基嘧啶) 相容性 离子交联聚合物 离子配位键交互作用.
  • 简介:Thecrystalandmolecularstructureofcopper(Ⅱ)dimericcomplexofS-methyl-B-N-(pyridineN-oxide-2-ylmethylidene)dithiocarbazatewithacetonitrile,[CuL(CH3CN)]2(ClO4)2,wasdeterminedbyX-raydiffraction.ThecomplexcrystalizesinmonoclinicsystemwithspacegroupP21/n,a=7.685(2),6=20.160(6),c=10.847(5)A,B=107.89(3),Z=2,Dc=1.788g/cm3,F(000)=835.8,u=18.17cm-1(Moka,R=0.057.EachCu(Ⅱ)ioninthecomplexissurroundedbyadistortedsquarepyramidal.ThebasalplaneiscomprisedofS,NandOatomsofoneligandtogetherwithaNatomofthesolvent--acetonitrile,whiletheaxialpositionisoccupiedbytheSatomoftheotherligand.ThebondlengthofCu-S(bridging)is3.038A.andCu-Cudistanceis3.700A.

  • 标签: COMPLEX of Cu (Ⅱ) Crystal and
  • 简介:Aseriesofsulfonatedpolyimides(SPIs)containingpyridinegroupswerepreparedbydirectpolycondensationfrom1,4,5,8-naphthalenetetracarboxylicdianhydride(NTDA),4,4'-diaminodiphenylether-2,2'-disulfonicacid(ODADS)and4-(4-methoxy)phenyl-2,6-bis(4-aminophenyl)pyridine(DAM).Theresultingcopolymersdisplayedgoodsolubilityincommonorganicsolvents.Flexible,transparent,toughmembraneswereobtainedviasolutioncasting.Allthefilmsshowedhighthermalstabilitywithdesulfonationtemperatureover300℃.TheyexhibitedprominentmechanicalpropertieswithYoung'smodulusaround2.0GPa.Highprotonconductivity(0.23S/cmat100%RH)wasalsoobserved.Moreimportantly,thenewmaterialsexhibitedlowwateruptake(30wt%-75wt%at80℃)andimprovedwaterstability,whichwereattributedtotheacid-baseinteractionbetweensulfonicacidandpyridinefunctionalgroups.

  • 标签: 磺化聚酰亚胺 膜材料 吡啶 质子交换 二氨基二苯醚 氨基苯基
  • 简介:CuSpinealmicrospherescongregatedfrominterleavingnanoflakeswiththicknessof40to200nmweresynthesizedbyapyridine-solvothermalprocessviathereactionbetweencupricchloride(CuCl2·2H2O)andthioacetamide(TAA,CH3CSNH2).TheproductswerecharacterizedbyX-raydiffractionandscanningelectronmicroscopy.UV-Visabsorptionspectrum,excitationandphotoluminescencespectraofCuSpinealmicrosphereswereobtainedatroomtemperaturetoinvestigatetheiropticalproperties.ApossiblegrowthmechanismontheformationofCuSpinealmicrospheresisproposed.ThefactorsinfluencingtheevolutionofmorphologiesofCuScrystalsincludingthedosageofthereactants,surfactant,andsulphur-sourcewerealsoanalyzed.

  • 标签: 溶剂热合成 CUS 松果体 吡啶 CH3CSNH2 硫代乙酰胺
  • 简介:新奇的肼单体,pyridine-2,6二度((4-aminophenyl)thioureido)羰基(PATC)高效地被综合并且有各种各样的芳香的dianhydrides的polymerized。因而,(pyridinethiourea-imide)poly,有好热性质的s(PPTI)和火焰retardancy被制作。PATC和PPTI的结构被FTIR描绘,<啜class=“a-plus-plus”>1H-NMR,<啜class=“a-plus-plus”>13与元素的分析,crystallinity,organosolubility,固有的粘性和胶化浸透一起的C-NMR光谱学色析法的大小。包含C=S,CONH和元的PPTI在聚合物脊梁代替了pyridine一半显示出非结晶的自然并且在高度极的器官的溶剂并且甚至在象tetrahydrofuran(THF)那样的不太极的溶剂是容易地可溶的。聚合物在0.911.16dL/g的范围有固有的粘性,分子的重量在6800077000g/mol之间被发现。PPTI的电的性质以在频率的一个范围上经常的电介质被估计。他们的热稳定性被在范围发现的10%重量损失温度决定519563在组之中未改变。1/1-sGC子单元的蛋白质层次从中年的比较w相?盼?盼在RCC被减少吗??

  • 标签: 高性能聚合物 合成效率 硫脲基 吡啶基 玻璃化转变温度 高热稳定性
  • 简介:Inthispaper,wehavestudiedtheadsorptionpropertiesofgoldbyα-alkylsubstitutedpyridineresin(BPR)inalkalinesolution.ThesingleanddualcomponentkineticmasstransferprocessofAu(I),Ag(I)andothermetalcyanideionswerealsoinvestigated.Theresultsobtainedshowthatthemasstransferratesofthecyanideionsintheresinphasearecloselyrelatedtothemolarratioandtheconfigurationofmetalcyanideions.TheelutionkineticsofAu(I)andothercyanideionsbyNH4SCNhasbeeninvestigatedsystematically.TheintraparticlediffusioncoefficientandactivationenergyofAu(I),Ag(I),Ni(I)Fe(Ⅲ)cyanideanionsweredeterminedinCI,NO3,OH-typeBPRresinatdifferenttemperatures.ItisfoundfromtheexperimentalresultsthatthemechanismforextractingAu(I),Ag(I)andothermetalcyanideanionsbyBPRresinbelongstoionexchangeprocess.Thedifferenceofactivationentropyofsomemetalcyanideanions(ΔS-ΔS^-)wasevaluated.

  • 标签: α-烷基取代嘧啶树脂 氰化物溶液 黄金提取
  • 简介:在这个工作,综合体新热地稳定(amide-imide)poly,有在n丁基甲基imidazolium溴化物的悬挂的2-pyridyl-1,3,4-oxadiazole单位的s作为反应媒介被报导了。新二羟基的酸从肼的反应被导出,2-(5-(3,5-diaminophenyl)-1,3,4-oxadiazole-2-yl)pyridine(POBD),和trimellitic酸酐。聚合物在丁基甲基imidazolium溴化物从diimide二酸(DIDA)和不同的芳香的肼的反应被准备,[bmim][Br],面对triphenyl亚磷酸盐(TPP)作为没有需要任何额外的部件的压缩代理人。poly准备了(amide-imide)s被FTIR描绘,元素的分析,并且通过模型混合物的合成。准备聚合物是可溶的在极并且aprotic溶剂例如DMF,DMSO,NMP和DMAc。聚合物答案的固有的粘性在在0.125g/dL的集中在集中的H2SO4测量在的0.521.33dL/g的范围(25

  • 标签: 芳香二胺 离子液体 酰亚胺 恶二唑 吡啶基 酰胺
  • 简介:Thepolymerizationofethylenebytwoiron-basedcatalysts,{[2,6-ArN=C(Me)2C5H3N]FeCl2}(Ar=2,6-C6H3-Me21;2,6-C6Hv3(i-Pr)v2Ⅱ)hasbeeninvestigated.CatalystⅡproduceshighermolecularweightpolyethylene(PE)andbroadenedpolydispersitiesrelativetocatalystⅠunderanalogousconditionsandallpolymersarelinear.Thekineticprofileswithironcatalystsshowedasmoothpatternduringbothratebuild-upandratelowering,whicharedifferentfromthemetallocenecatalysts.ThepolymerizationactivityincreaseswithAl/Fevalueandanoptimumtemperaturerangeat40~45℃wasobserved.ThemolecularweightofPEdecreaseswiththeincreaseofAl/Feratioandriseofpolymerizationtemperature.

  • 标签: ETHYLENE POLYMERIZATION Transition metal CATALYST
  • 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:新奇的有点芳香的肼,N-(4-(4-(2,6-diphenylpyridine-4-yl)含苯氧基)苯基)-3,5-diaminobezamide(DPDAB),与4-经由3,5-dinitrobenzoylchloride的芳香的亲核的替换被综合(4-(2,6-diphenylpyridine-4-yl)含苯氧基)苯胺(DPPA),由催化钯的肼列在后面减小。这单体被用来commerically与几基于反应准备polyimides(PI)avaiabletetracarboxylicdianhydrides象pyromellaticdianhydride(PMDA)那样,benzophenonetetracarboxylicacidedianhydride(BTDA)和自行车[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylicdianhydride(BCDA)。这些PI在0.340.76dL/g的范围有固有的粘性并且在各种各样的aprotic显示出好溶解度极的溶剂。PI的眼镜转变tempratures(Tgs)在184302的范围

  • 标签: 芳香二胺 聚酰亚胺 热稳定性 吡啶 三芳基 非质子极性溶剂