简介:Reactionofglycinewithphosphorustrichlorideinpresenceoftriethylaminehasurnishedtheovelspirohydridophosphorane.Itsstructurehasbeencharacterizedbyelementalanalysis,n.m.r.spectraandmassspectrum.Thecompoundreactedwithphenylisothiocyanatetogive2-phenyliminothiazolid-5-one.
简介:TheNb-bromomethylderivative(2)ofgelsemine,aquaternaryammoniumsalt,wasfoundtoberecalcitranttowardHofmanntypealkalinedegradationwhichhasbeensuccessfulinothercases.Instead,are-distributionoftheN-methylgrouptookplace,givingriseto3a,1,3band3c,indescendingorderofRfvalues.
简介:Sixnewcompounds,α,β-KaHb[GeW9M3(H2O)3O37].xH2O(M=Al,Ga,In;a+b=7)andα-K9H5[Ge2W18Ga6(H2O)3O74].20H2O,weresynthesizedfromthelacunaryprecursorsαandβ-GeW9O3410-andcharacterizedbyelementalanalysis,spectroscopyandelectrochemistry.Tungsten-183NMRspectraofthetitlecomplexesconsistoftwolineswithintensityratio2:1asexpectedfortrisubstitutedheteropolyanions.Theintensityratioofα-Gacompoundis1:2,whichisdifferentfromothers(2:1).WiththehelpofFABmassspectrum,weconcludedthatitisadimerwithD3h,structureinaqueous,andtheothersexistbymonomerswithC3cstructures.
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简介:TheelectrochemicalformationofMg-LialloyswasinvestigatedinamoltenLiCl-KCl(58-42mol%)eutecticmeltat723K.ThecyclicvoltammogramforaMoelectrodeshowedthattheelectroreductionofLi~+proceedsinasinglestepandthedepositionpotentialofLimetalwas-2.40V(vs.Ag/AgCl).ForMgelectrode,theelectroreductionofLi~+takesplaceatlesscathodicpotentialthanthatattheMoelectrodewhichwascausedbytheformationofMg-Lialloys.PhaseofthedepositedMg-Lialloyscouldbecontrolledbytheelectrolysispotential,andthesampleswerecharacterizedbyX-raydiffractionandscanningelectronmicroscopy.Theresultsshowedthatα-Mgandβ-Liphaseswereobtainedat-2.35and-2.55V,respectively.
简介:Itwasfoundthatphosphorylationofsmallpeptidecouldimprovethesensitivityinmassspectrometry.DensityfunctionaltheorycalculationsshowedthattheenergyfortheprotonationofN-(O,O′-dimethyl)phosphorylglycylglycineislowerthanthatofglycylglycine.Thesecouldhelptounderstandingtheexperimentalresults.
简介:STUDIESONHETEROMACROCYCLICPOLYETHER(XIV)THESYNTHESISOFSELENACROWNETHERWITHHYDROXYGROUPANDDISELENA-AZA-CROWNETHERHanShengXu;Ju...
简介:Arapidandeffectivemethod,solidphaseextractioncoupledwithhighperformanceliquidchromatography(SPE-HPLC),wasappliedtotheseparationandanalysisofginsenosides.WatersOASISHLBwasusedforconcentratingandpurifyingsamplesandAlltimaC_(18)(53mm×7mm,3μm)chromatographycolumnwasusedforseparatingginsenosideRg_1,Re,Rb_1,Rc,Rb_2andRd.Theseginsenosideswereanalyzedwithin20mininourgradientelutionprocessandtheequilibriumtimeofthechromatographycolumncostonly5min.Moreover,therewasnoobviousbaselinedriftinourexperiment.Thismethodwasusedtoanalyzethecontentsofginsenosidesindifferentginsengproductsforqualitycontrol.Fourginsengproductswerestudied,includingtwokindsofcapsules,onekindoftabletandonekindofinjection.Theresultsshowthatthemethoddevelopedinthispaperhadgoodaccuracy,linearityandprecision.Therefore,thismethodcouldbeappliedinqualitycontrolofginsengproducts.
简介:TwospeciesofN-arylpyrazolescontainingactiveaminogroupweresynthesized.AndformylationsofN-arylpyazolescontainingaminoindifferentpositionofpyrazoleringsusingVilsmeier-Haackreactiongaveaseriesofusefulpyrazoleintermediates.Theimportantfeaturesofthisprotocolwerecheapmaterials,easyprocess,mildreactionconditionsandgoodyieldofproducts.
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简介:THEREACTIONOFp-NITROPHENYLSULFONYLACETONITRILEWITHα,β-UNSATURATEDESTERSANDNITRILES¥GuoRenYUEandZhengZhang(DepartmentofChemist...
简介:Amain-chainliquidcrystallineionomer(MLCI)containingsulfonicgroupwassynthesizedbyaninterfacialcondensationreaction.TheMLCIwasblendedwithpolybutyleneterephthalate(PBT)andpolypropylene(PP).MLCIinteractedwithboththedispersed(PP)phaseandthematrix(PBT)phasetomodifytheinterfacialinteractionofPBTandPP.Differentialscanningcalorimetry(DSC),scanningelectronmicroscopy(SEM)andFTIRimagingsystemanalysisdemonstratedthesignificanceofinterfacialinteractioninthepolymerblends.MLCIbroughtaboutgoodadhesionattheinterfacial,whichreducedthedispersephasesizeandenabledafinePPphaseatmatrix.ThemechanicalpropertiesoftheternaryblendswereimprovedwhenaproperamountofMLCIwasadded.Thiswasattributedtoenhancedadhesionattheinterface,whichinvokedbettermechanicalpropertiesintheblends.
简介:Condensationofmethyl7-methylcoumarin-4-acetate(2)withprimaryaminesandwithan-thranilicacidgave7-methyl-2-oxo-N-aryl-2H-[1]-benzopyran-4--acetamide(4a—d)and(7),respectively.Compound7underwentcyclizationtogive2-(7-methyl-2-oxo-2H-[1]-benzopyran-4-yl)-methyl-4H-3,1-benzoxazin-4-one(3).Thereactionof3witharomaticaminesgavethecorrespondingquinazolonederivatives5whichtautomerisestothethermodynamicallymorestableisomer6,whereasitsreactionwithGrignardreagentsandaromaticaldehydesgave8a,8b,and9a,9b,respectively.
简介:InanefforttoutilizeNMRtechniquefortheanalysisofthestructuralcomponentsofwoodandbiomassessuchaslignin,wemadeacomparativestudyoflignincontentsofseveraltypesoflignocellulosicmaterialsbothbeforeandafterenzymatichydrolyses.Tothisend,EucalyptusGlobulus,Norwaysprucethermomechanicalpulp(TMP)cornstoverandEucalyptuskraftpulpwereball-milledandtreatedwithcellulasetopreparematerialswithhighlignincontents.Thesematerialswereanalyzedvia31PNMRinionicliquids.Theresultsshowthatthecontentsofvariousfunctionalgroupsforthelignocellulosicmaterialsafterenzymatichydrolysesaregenerallyinagreementwiththosefromtheircorrespondingenzymaticmildacidolysisliginins(EMALs),indicatingthat31PNMRanalysisoflignocellulosicmaterialsinionicliquidsisapromisingmethodforquantitativecharacterizationoflignocellulosicmaterials.