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.
简介:ByusingOH-terminatedpolyaryletherdendrimerandN-Fmoc-glycineasrawmaterials,thedendriticpolyarylether2-aminoacetate(G3-NH2)wassynthesizedviatwostepreactions.G3-NH2asamacroinitiatorforthering-openingpolymerizationofγ-benzylL-glutamateN-carboxyanhydridewasinvestigated.Itisfoundthattheresultingcopolymerspossessedrelativelyhighmolecularweightandnarrowmolecularweightdistribution(1.12
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.
简介:Tetrazole-1-aceticacidwasfoundtoserveasasuperiorligandforCuI-catalyzedN-arylationofimidazoleswitharyliodidesunderalowcatalystloading(5mol%ofCuI).AvarietyofaryliodidescouldbeaminatedtoprovidetheN-arylatedproductsingoodtoexcellentyieldswithouttheneedofaninertatmosphere.
简介:Startedfrom5-hydroxy-2-pentanone,(R)(E)-3,7-dimethyl-2-octene-1,8-dioicacid,callosobruchusicacid,wassynthesizedviafivestepswithD-(-)-camphorsultamasthechiralauxiliary.Itwasofgoodopticalpurityandyield.
简介:(R)-N-乙酰四氢噻唑-2-硫酮-4-羧酸在三乙胺存在下同乙酰氯反应得到光学活性产物(R)-N-乙酰四氢噻唑-2-硫酮-4-羧酸.用半经验的量子化学方法研究反应物及产物的电子结构和反应热焓.
简介:AnefficientroutetoprepareL-glucoseandL-galactoseisdescribed.TheL-sugarsareachievedbyusingthestrategyofswitchingthefunctionalgroupsatC1andC5ofD-glucoseandD-mannose.TheoxidationandreductionofthesilylenoletheratC1andthelead(IV)tetraacetatemediatedoxidativedecarboxylationatC5arethekeysteps.L-GlucoseandL-galactosearepreparedinaconvenientandinexpensiveway.
简介:ReactionsofCuSCNwithtetramethylthiuramdisulfideinCH3CNinthepresenceofstyreneandN,N,N',N',N'-pentamethyldiethylenetriaminegaverisetoanewcopper(Ⅰ)complexofN,N'-dimethyldithio-cabamate{[Cu(S2CNMe2)]2}n.ThetitlecompoundcrystallizedinthetriclinicP-1spacegroupwithlatticeparametersα=0.7610(4)nm,b=0.8911(4)nm,c=0.9268(5)nm,α=68.66(1)°,β=83.88(2)°,γ=79.31(2)°,V=0.5748(5)nm^3,Z=2.Thecompoundhasaunique1DchainstructurecomposedofCuSCSCuSCSeight-memberedringsandapairofCu-Sbonds,thestructureofwhichhasbeendeterminedbysingle-crystalX-raycrystallography.Theisolationofthiscompoundmayprovidesomehelpfulinformationforthecauseoftheinductionperiodsofthereverseatomtransferradicalpolymerization.
简介:ThepropertiesofPbn(n=2―30)clustersincludingbindingenergies,seconddifferencesinenergy,andHOMO-LUMOgaps,especiallyfragmentationenergiesandionizationpotentials,havebeenstudiedbyabinitiocalculation.ThemainfragmentationproductsofPbn+areshowntobePb+Pbn-1+forn≤14andtwosmallclusterfragmentsforlargeroneswithn>14.ThePb13+appearsfrequentlyastheproductsinthefragmentationsoflargeclusters.Also,thecalculatedionizationpotentialsoftheclustersareconsistentwiththeexperimentdata.
简介:Aseriesofaromaticimineswerereducedtocorrespondingaminesinexcellentyieldsby2-phenyl-N,N-dimethylbenzimidazoline(PDMBI)photochemicallyinthepresenceofmagnesiumperchloride(Mg(ClO4)2).AMg2+mediatedphotoinducedelectrontransfermechanismwasproposed.
简介:Thetwocompounds,2,2-dimethyl-4-S-(N,N-dimethyldithiocarbamato)-5-(1,2,4-triazol-l-yl)-propione(1)and2,2-dimethyl-4-S-(N,N-diethyldithiocarbamato)-5-(1,2,4-triazol-1-yl)-3-propione(2),werepreparedbyreactingN,N-dialkyldithiocarbamatesodiumwith2,2-dimethyl-4-bromo-5-(1,2,4-triazol-1-yl)-propione.Theirstructureswereidentifiedbyelementalanalysis,IRand^1HNMRspectroscopy.Thestructureof1hasbeendeterminedbyX-raysinglecrystalstructureanalysis.ItcrystallizesinmonoclinicsystemwithspacegroupP21/c,a=1.2315(3)nm,b=1.2057(2)nm,c=1.2532(3)nm,β=118.55(3)°,Z=4,V=1.6345(6)nm^3,Dc=1.221g/cm^3,μ=0.324mm^-1,F(000)=640,finalR1=0.0449.ThereisobviouspotentiallyweakC—H...Nintermolecularinteractioninthecrystal,whichstabilizesthecrystalstructure.Theresultofthebiologicaltestshowedthatthetwocompoundshavefungistasisandplantgrowthregulatingactivities.
简介:Aggregationofsomenitrogen-containingheterocycliccompoundshavebeeninvestigatedbymeansoffluorescencespec-troscopyinaqueousoraquiorganobinarymixturesofdifferentΦvaluesforthefirsttime.TheaggregatorsstudiedareN-butylcarbazole(CBZ-4),N-octylcarbazole(CBZ-8),N-do-decylcarbazole(CBZ-12),andN-hexadecylcarbazole(CBZ-16).Theiraggregatingtendencieshavebeenevaluatedbymeasuringtheircriticalaggregateconcentrationvalues(CAgC’s).OurresultsindicatethattheN-alkylcarbazoles,justliketheanthracenederivativeswithdifferentchain-lengths,canalsobeusedasfluorescenceprobesforevaluatingaggregatingtendenciesorCAgCvalues.
简介:采用HF/DFT的混合泛函PBE0和UPBE0优化了配合物[Os(PH3)2(CN)2(N^N)](其中N^N=2,2′-吡啶)的基态和激发态结构.在基态和激发态结构的基础上,利用含时密度泛函理论(TD-DFT)方法,结合极化连续介质(PCM)模型分别计算了它在二氯甲烷(1)、甲醇(2)、气态(3)和乙腈(4)溶液中的吸收和发射光谱.研究结果表明:优化得到的几何结构参数和相应的实验值符合得非常好.在极性较大的溶剂(2和4)中Os—P(1)和Os—C(1)键较长,Os—N(3)键较短,溶剂的极性会影响配合物的电子云分布.配合物在1-4溶剂中的最低能吸收和发射均来自分子轨道68→71的激发,该激发被指认为[d(Os)+π(CN)+π(N^N)→π*(N^N)]的跃迁具有混合的MLCT/LLCT特征.配合物在1-4溶剂中的最低能吸收和发射分别在471,410,488和445nm以及598,536,634和545nm,表明随着溶剂极性的逐渐增大(3〈1〈4〈2),最低能吸收和发射发生明显的蓝移.这显示出通过改变溶剂极性可以调节配合物的发光颜色.
简介:Usingfourβ-cyclodextrinderivatives,2,6-di-O-benzyl-3-O-heptanonyl-β-CD,2,6-di-O-benzyl-3-O-octanonyl-β-CD,2,3-di-O-benzyl-6-O-heptanonyl-β-CD,and2,3-di-O-benzyl-6-O-octanonyl-β-CD,aschiralstationaryphasesofcapillarygaschromatography(CGC),theenantiomersofSharplessepoxideswerewellseparated.Theenantiomerexcessvalues(e.e.%)ofsomechiralSharplessepoxideswerealsodeterminedsuccessfullyusingtheseCDs.
简介:SodiumdithioniteinitiatedsulfinatodehalogenationofBrCF2CF2Risstudied.