学科分类
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383 个结果
  • 简介:多代替的dihydrofurans是为自然产品和药品的合成的珍贵中介。可观的注意集中于发展有效并且为他们的准备的regioselective方法。把K2CO3用作一个底,与fur-2-oylmethyltriphenylarsonium溴化物1的反应和乙醇2-acetyl-3-arylacrylate2在在房间温度的tetrahydrofuran,我们发现一个有效协议被完成综合trans-3-aryl-4-carbethoxy-2,3-dihydro-2-fur-2-oyl-5-methylfurans3在有高stereoselectivity的好产量。化合物3的结构被红外,1HNMR,MS和HRMS证实。为3的形成的机制被建议。

  • 标签: 选择性铅版合成 叶立德 氢化砷 二氢呋喃
  • 简介:Treatmentof4-amino-3-(1-aryl-5-methyl-1,2,3-triazol-4-yl)-5-mercapto-1,2,4-triazoles/2-amino-5-(1-aryl-5-methyl-1,2,3-triazole-4-yl)-1,3,4-thiadiazoleswithbenzaldehyde,acetoneandω-bromoacetophenonewastestedandcompared.ThetitlecompoundsSchiffbases,amides,imidazolo[2,1-b]-1,3,4-thiadiazolesand7H-s-triazolo[3,4-b]-1,3,4-thiadiazineshavebeenconfirmedbyelementalanalyses,^1HNMR,IRandMSspectra.AllthecompoundshavealsobeenscreenedfortheirantibacterialactivitiesagainstB.subtilis,S.aureusandE.coli.

  • 标签: 合成 抗菌活性 4-氨基-3-(1-芳基-5-甲基-1 2 3-三唑-4-基)-1 3 4-噻重氮 衍生物
  • 简介:Thioglycolicacid(TGA)-stabilizedCdTenanocrystals(NCs)werepreparedwithsodiumtelluriteastelluriumsource,whichavoidsthecumbersomeprocessesassociatedwithH2TeorNaHTesources.FluorescentCdTe/SiO2compositesweresynthesizedbyasol-gelmethodwithouttheexchangeofsurfaceligands.ThephasestructureofCdTeNCswasinvestigatedbyX-raydiffractometry.Forcomparison,somecharacterizationsweredoneforboththeCdTeNCsandthecomposites.CdTeNCsandCdTe/SiO2compositeswerecharacterizedwithTEM,digitalcameraandfluorescencespectrophotometer.ThestabilityofCdTeNCsandthecompositeswereinvestigatedinphosphate-bufferedsaline(PBS)bufferandthefluorescentpropertiesofthecompositeswerediscussedindetail.

  • 标签: 复合材料 荧光性质 CdTe纳米晶 合成 磷酸盐缓冲液 透射电子显微镜
  • 简介:ThephotodegradationreactionrateofCHCl3inTiO2particulatesuspensionwasimperovedsignificantlybyHCl-treatment.TheeffectofHCl-treatmentonthephotocatalyticactivityofTiO2wasstrdiedinaPECcellbyusingIntensity-ModulatedPhotocurrentSpectroscopy(IMPS).ThemagntudeofphotocurrentresponseandthecharacteristicfrequenciesoftheupperandlowersemicirclesinthecomplexplaneofIMPSresponsewereanalyzed,andtheccathodicandanodicreactionprocessesofphotogeneratedholesandelectronswerediscussed.Theincreasesinthecathodicandanodicphotocurrentresponseandinthetimeconstantsofbothcathodicandanodicreactionprocessesofphotogeneratedholesandelectronswerediscussed.TheincreasesinthecathodicandanodicphotocurrentresponseandinthetimeconstantsofbothcathodicandanodicreactionprocessesindicatethatHCl-treatmentleadstotheimprovementofthephotocatalyticactivityofTiO2andachangeofthephotocatalytickineticmechanism.

  • 标签: TIO2 IMPS 二氧化钛晶体 三氯甲烷 化学处理 催化剂
  • 简介:2-Oxoderivativesofglycosides,called2-ketoglycosidesorglycoside2-uloses,arebiologicallyimportantincarbohydratemetabolismandareveryusefulinsynthesisofbranched-chainsugarsandaminosugars.Verylittleisknownoftheirchemistrybecauseofthehighsusceptibilityofthesecompoundstodegradationinsolution,andinparticulartheirinstabilitytobase.Thusitisimportanttostudythereactivitiesof2-ketoglycosides.Inapreviouspaper,wereportedthetransformationof2-ketoglycosidesinpyridinesolution.Duringthetransformationof2-and3-ketoglycosides,ademethoxylationreactionoftheenolintermediatewasshowntotakeplacesimultaneouslywitheliminationtogivehex-1-enopyran-3-ulose.

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  • 简介:Thecomplexes(PhCH2)2Sn(MBT)2(2)and(PhCH2)3Sn(MBT)(3)(HMBT:2-mercaptobenzothiazole)havebeensynthesizedandcharacterizedbyelementalanalyses,andIR,^1H,^13C,^119SnN-MRspectrometriesandX-raydiffraction.Studiesonthecrystalstructuresof2and3showthatHMBTactsasbidentateligandthroughchelationofNandSatoms.Complex2containsasix-coordinatetinatomwiththeaxialangleC(15)-Sn(1)-C(22)129.6(2)°.Andthetinenvironmentofcomplex3isadistortedcis-trigonalbipyramidwithC(8)-Sn(1)-N(1)158.80°.

  • 标签: 合成 晶体结构 苄基锡衍生物 2-巯苯噻唑 二齿配位基 氮原子
  • 简介:CO2-copolymerbasedpolyurethanefoamsweresynthesizedandcharacterizedinthispaper.Thefoamswerefoundtohavehigherstrengthandlowerheatofcombustionthantheconventionalpolyetherpolyurethanefoams.Theymayfindwideapplicationsinmanyfields.

  • 标签: 合成 CO2 环氧化物 共聚物 聚氨酯泡沫 聚碳酸酯
  • 简介:hePhotocatalyticcharacterizationofTiO2supportedonactivecarbonwasinvestigatedforphotocatalyticdecompositionofdichloroaceticacid.ItwasfoundthatTiO2/ACexhibitedahigherphotocatalyticactivitythanpureTiO2.ThereasonisthatactivecarbonactingaspowerfuladsorbentsupportsmakeshighconcentrationenvironmentsoforganicpollutantmoleculesaroundTiO2particles.

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  • 简介:在这研究,一新(乙烯基氯化物)(PVC)poly,为Ho3+离子的膜传感器作为ionophore基于N-phenyl-2-(thiophen-2-ylmethylene)hydrazinecarbothioamide(PHC)被准备。这个传感器与阳离子的变化比较向钬离子表明了好选择和敏感,包括碱,碱的地球,转变和重金属离子。电极的反应性质上的膜作文和pH的效果被调查。详细,建议传感器展出了Nernstian行为(与20.4的一个斜坡??洀????x

  • 标签: 膜传感器 离子测定 膜制备 钬离子 苯基 噻吩
  • 简介:Inthiswork,acidfunctionalizedmulti-wallcarbonnanotubes(MWCNTs)weremodifiedwithimidazolium-basedionicliquids.Theselectiveoxidationofvariousalcoholswithhydrogenperoxidecatalyzedby[PZnMo_2W_9O_(39)]~(5-),ZnPOM,supportedonionicliquids-modifiedwithMWCNTs,MWCNTAPIB,isreported.Thiscatalyst[ZnPOM@APIB-MWCNT],wascharacterizedbyX-raydiffraction,scanningelectronmicroscopy(SEM)andFT-IRspectroscopicmethods.Thisheterogeneouscatalystexhibitedhighstabilityandreusabilityintheoxidationreactionwithoutlossofitscatalyticperformance.

  • 标签: 多壁碳纳米管 离子液体 催化剂 多金属氧酸盐 氧化改性 H2O2
  • 简介:TwonewintercalationcompoundsFe0.90PS3(phen)0.41(1)(phenstandsfor1,10-phenanthrolineincludingapartof1,10-phenanthrolineH+)andFe0.83PS3(bipy)0.34(2)(bipystandsfor2,2’-bipyridineH+)weresynthesizedbythereactionofthelayeredFePS,with1,10-phenanthrolineor2,2’-bipyridineinthepresenceofaniliniumchloride.Theywerecharacterizedbyelementalanalyses,powderX-raydiffraction(XRD),infraredspectroscopy.Thelatticespacingoftheintercalatewasexpandedby0.90nmforFe0.90PS3(phen)0.41and0.57nmforFe0.83PS3(bipy)0.34withrespecttothepristineFePS3,indicatingthattheringplaneoftheguestsisperpendiculartothelayerofthehost.TheUV-visabsorptionspectraofthefiltrateinpreparationoftheintercalatesindicatethat1,10-phenanthrolineor2,2’-bipyridinealsoactsasacomplexingagenttoremoveintralamellarFe2+ionsintothesolutionduringintercalation.Themagneticpropertiesof1and2werestudied.

  • 标签: INTERCALATION FePS3 1 10-PHENANTHROLINE 2 2’-bipyridine
  • 简介:存取2-substituted-N1-carbethoxy-2,3-dihydro-4(1H)的一条灵巧、有效、新奇的途径-quinazolinones是被代替的N-carbethoxyanthranilamide的冷凝作用用p-toluenesulfonic酸在refluxing2,2,2-trifluoroethanol或hexafluoroisopropanol与烷基,aromatic或异种aromatic醛开发催化剂。

  • 标签: 三氟乙醇 六氟异丙醇 氟溶剂 溶剂效应 喹啉氮杂化合物
  • 简介:Anumberofnaphthalenedonorcompoundsthatpossessanadamantanaminebindingmoietyandan(OCH2CH2)n(nn1,2,3,4,6,8)spacerweresynthesized.Thefluorescencequenchingbetweenthesedonorsubstratesandmono-6-O-p-nitrobenzoyl-β-cyclodextrin(pNBCD)andmono-6-O-m-nitrobenzoyl-β-cyclodextrin(mNBCD)wasstudiedindetail.Itwasfoundthatveryefficientfluorescencequenchingcouldoccurinthesesupramolecularsystems.Thisquenchingwasattributedtothephotoinducedelectrontransferinsidethesupramolecularassemblybetweenthenaphthalenedonorsandcyclodextrinacceptors.DetailedStern-VolmerconstantsweremeasuredandtheywerepartitionedintodynamicStern-Volmerquenchingconstantsandstaticbindingconstants.Itwasdemonstratedthatthebindingconstantsbetweenallthenaphthalenecompoundsandcyclodextrinsarethesameastheypossessthesamebindingsite,i.e.,adamantanamine.

  • 标签: 光致电子转移 Host-Guest化合物 2-萘基-(乙烯氧基)n-金钢石 单-6-O-p-硝基苯甲酰基-β-环式糊精 单-6-O-m-硝基苯甲酰基-β-环式糊精
  • 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
  • 简介:过量臼齿的卷VmEand运动学的粘性为丙烯乙二醇monomethyl醚(1-methoxy-2-propanol)的二进制混合物作为作文的一个函数被测量了,MeOCH2CH(哦)我,丙烯乙二醇monoethyl醚(1-ethoxy-2-propanol),EtOCH2CH(哦)我,丙烯乙二醇monopropyl醚(1-propoxy-2-propanol),PrOCH2CH(哦)我,丙烯乙二醇monobutyl醚(1-butoxy-2-propanol),BuOCH2CH(哦)我,和丙烯乙二醇tert丁基醚(1-tert-butoxy-2-propanol),t-BuOCH2CH(哦)我与1-butanol臼齿的体积是的过量为系统2-butanol+1-methoxy-2-propanol,和+1-propoxy-2-propanol越过为有1-butanol的所有系统的全部范围ofcomposition否定、积极,为为系统2-butanol+1-ethoxy-2-propanol,和+1-tert-butoxy-2-propanol的系统2-butanol+1-butoxy-2-propanol,和变化符号否定。从试验性的数据,在从xii的动态粘性的偏差被计算了。两过量臼齿的卷和粘性偏差被方法用一个Redlich-Kister类型多项式方程相关为二进制系数和标准错误的评价最少平方。

  • 标签: 过剩摩尔量 混合物 烷氧基 化学反应
  • 简介:热行为,机制和在一个规划温度的模式的标题混合物的发热的第一阶段的分解反应的运动参数借助于DSC,TG-DTG和红外被调查了。反应机制被建议。在微分形式,明显的激活精力(Ea)和这反应的pre指数的因素(A)的实验运动模型功能是(1-)?1.119,211.3kj/mol和1020.2s?1分别地。混合物的热爆炸的批评温度是202.2爠慥瑣潩?㈠低??湡敧漠??????????????鈿酌顛鱎?????疞????陴?陴?T

  • 标签: DECOMPOSITION GLYCOLURIL KINETICS mechanism