Advanced-Organic-Chemistry1-高等有机化学课件.ppt

AdvancedOrganicChemistry(1)高等有机化学（I）Instructor:JingKuiYANGCollegeofChemistryandChemicalEngineeringGraduateUniversityofCAS(GUCAS)1AdvancedOrganicChemistry(1)AdvancedOrganicChemistry(1)Chapt1:OrganicReactionMechanism(3-4)Chapt2:SolventsEffects(5)NationalHolidayDay(6)SolventsEffects(7)Chapt3:Stereochemistry(9,10,11)Chapt4:Organicreactionactiveintermediatesanddetermination.(12,13)Chapt5:ConcertedReaction(14)Chapt6:OrganicPhotochemistryandElectrochemistry(15,16A)Chapt7:CatalyticReactionandMechanism(16A,17)2AdvancedOrganicChemistry(1)CChapt4:Organicreactiveintermediates有机活性中间体Freeradicals(自由基)Ionradicals(Cationradical,anionRadicals)离子自由基Carbene(卡宾),Nitrenes(乃春)Benzyne(arynes)(苯炔)Carbocations(CarbonCation)(碳正离子)Carbanions(CarbonAnion)(碳负离子)Antiaromaticcompounds(反芳香化合物)Strainedrings(张力环)Introduction,Properties,Preparations,Reactions,Determination3Chapt4:OrganicreactiveinteAdvanced-Organic-Chemistry1-高等有机化学课件Advanced-Organic-Chemistry1-高等有机化学课件NobelPrizeforChemistryin1994GeorgeOlah,1927-,Hungary(匈牙利）USAUniversityofSouthernCaliforniaLosAngeles,CA,USABiographyfor his contribution to carbocation chemistry6NobelPrizeforChemistryin1OthersNobelPrizeforChemistryin1999infemtosecondspectroscopyAhmedH.Zewail,1946-,EgyptandUSACaliforniaInstituteofTechnologyPasadena,CA,USANobelPrizeforChemistryin1992inTheTheoryofelectrontransferreactionsMarcus,1923-Montreal,CanadaandUSACaliforniaInstituteofTechnologyPasadena,CA,USAAlsoin1967,19837OthersNobelPrizeforChemisReactiveIntermediates:TheMethodsTheFieldofReactiveIntermediatesisahighlyinterdisciplinaryfieldthatrequiresthecombinationofamultitudeofmethodstraditionalspectroscopicmethodsultrafastspectroscopicmethodselectrochemistrycomputationalchemistrysyntheticchemistryphotochemistrykineticsbiochemistryIntelligence/Imagination8ReactiveIntermediates:TheMeReactiveIntermediates:TheCompoundsWhatunifiesthesedisciplinesanddefinesthefieldisthesimplequestionof:Howshortlivesspeciesdeterminetheoutcomeofchemicalreactions(生命力多短的片段决定反应的结果).Thereactionsinquestioncaninthemselvescomefromtotallydifferentfields.Studiesofthevisualprocessintheeyesretina(视网膜),explosionsorgrowthofmaterialthroughCVDprocesses.Mechanisticresearchnearlysynonymous(同意,等同于)withresearchintoreactiveintermediatesbecausethemajorityofchemicalreactionsinvolveshortlivedintermediates.CVD:ChemicalVaporDeposition(化学气相沉积法）9ReactiveIntermediates:TheCohttp:/chiuserv.ac.nctu.edu.tw/htchiu/cvd/home.html/CVDChemicalVaporDepositionischemicalreactionswhichtransformgaseousmolecules(precursor),intoasolidmaterialintheformofthinfilmorpowder,onthesurfaceofasubstrateGasSolidmaterialssubstrate10http:/chiuserv.ac.nctu.edu.twRadicalsCarbeniumcationCarbeniumanionsSextetspecies(六电子体系)(carbenes,nitrenesetc)16VEtransitionmetalcomplexesAntiaromaticcompoundsStrainedringsBiochemicalreactionsfrequentlyinvolvespeciesfromthelistaboveand,inaddition,unusuallyreactiveintermediatesthatowetheirhighreactivitytotheviolationofmoresubtlestabilitycriteria.Examples:11RadicalsExamples:11carbenes,nitrenes,silylenes,freeradicals,radicalions,diradicals,carbocations,carbanions,N,S,O,P,Si等及其他两性元素有相似可能性12carbenes,nitrenes,silylenes,中间体稳定性不一样someverystablecanbeisolated,butothers(highlyreactivity)donotTwotypesofOrganicReactions:1),StepwiseReactions(分步反应):可以分出中间体2),ConcertedReaction(协同反应)理想状态:没有中间体(?)MyHypothesis:toofastandveryhighreactivityandcannotbecheckedbycurrentinstrument?13中间体稳定性不一样TwotypesofOrganic(活性中间体)14(活性中间体)141515电荷转移复合物(ChargeTransferComplex,CTC)ElectronTransfer,ET16电荷转移复合物(ChargeTransferComple多重性2I+1I000117多重性2I+1I17HaloniumionEnolate/enol/Ynol(烯醇或炔醇)diradicalsOxireneBenzyne(苯炔)18HaloniumionEnolate/enol/Ynol(keteneisocyanateYlide(叶立德)KetylRadical羰游离基16VE19keteneisocyanateYlide(叶立德)KetyCation/AnionRadical(阳/阴离子自由基)20Cation/AnionRadical(阳/阴离子自由基只作参考21只作参考21222223232424http:/www.pacifichem.org/c_symposia/c_symp_9.htm25http:/www.pacifichem.org/c_syAngewandteChemieInternationalEditionVolume37,Issue24,1999,3340-3350DynamicBehaviorofOrganicReactiveIntermediates(p3340-3350)BarryK.CarpenterAbstract|FullText:PDF(Size:301K)只做参考!“OrganicReactiveIntermediates,Chem.Rev.1992,92,1611-1647.26AngewandteChemieInternationaKeywordsComputerchemistry;Diradicals;Kinetics;Moleculardynamics;Supercriticalfluids;Computerchemistry;Diradicals;Kinetics;Moleculardynamics;SupercriticalfluidsAbstractAnunexpectedyesistheanswertheauthorgivestothefollowingquestions:Ifareactiveintermediatewasfacedwithtwoequallyhighenergybarrierstoproductformation,couldthekineticproductratioeverbeanythingotherthan1:1?Ifthetwobarrierswereofunequalheight,couldthereeverbeapreferencetoformtheproductthatcorrespondstothehigherbarrierpathway?Thebasisforthisyesaretheresultsfrommoleculardynamicssimulationsandexperimentsthatsuggestthattheinterpretationofreactionmechanismsbystatisticalmodelsisnotalwayscorrect.只做参考!27KeywordsComputerchemistry;DChapt4.2FreeRadicals(自由基)有未成对（unpaired)电子的中性原子、基团或分子。NeutralChemicalspeciesthathaveasingleunpairedelectron反应特点：与溶剂极性无关易在气相生成不被酸或碱催化取代基效应与离子型反应不同(既可被吸电子，也可被供电子基团稳定？）一般没有很好的线性自由能关系（或特别小0）对杂质非常敏感：O2，NHR1R2，SH，PhOH(可形成不 活泼的自由基，可用于反应机理判断）有特定的电子自旋（ESR/EPR）或核磁（CIDNP）共振谱28Chapt4.2FreeRadicals(自由基)有Firstusedby:Lavoisierin18thcenturytodesignatesomepolyatomicfragmentofamoleculewhichremainsunchangedduring1ormorechemicaltransformations.1849,Frankland,believedbutreallyproducemixturegases.1900MosesGombergPh3CCl+Hg/PhH=Ph3C.-Dimeryellowcolour1927:Paneth/Hofeditz;1937,Kharasch(RadicalChainmechanism),Hey/Waters:Proposingaradicalmechanism30yearslater,theorysuggested,andmoreandmorefreeradicalsreactionsfoundastheimportantintermediatesinmanyreactionsHistoryofRadical29Firstusedby:Lavoisierin1Deepviolet(紫)crystalsBlueCrystalsRed-Brownliquid30Deepviolet(紫)crystalsBlueCrStructureofOrganicFreeRadicalsMostoftheOrganicFreeRadicalshavethefollowingstereostructure:SP3SP2(planarconformation)(unpairedelectroninPorbit)G=2.5KJ/mol31StructureofOrganicFreeRadiG=2.5KJ/molistoosmall,turnoverofitisveryeasy,somanyfreeradicalreactionofachiralcompoundswillgivetheraceme(外消旋体)Stabilityofradicals:Moresubstitutes,morestableR3C.R2CH.RCH2.Reason:Hyperconjugation32G=2.5KJ/molistoosmall,turInsolution:severaldaysAssolid:Stableupto300oC33Insolution:33TheProductionofFreeRadicalsThermolysis(热解)Photolysis(光解)Oxidation_Reduction(氧化还原)34TheProductionofFreeRadicalESR:ElectronSpinResonance电子自旋共振谱EPR:ElectronParamagneticResonance电子顺磁共振谱CIDNP:ChemicallyInducedDynamicnuclearPolarization化学诱导动态核极化（核磁）ENDOR:Electron_NuclearDoubleResonanceSpectroscopy电子和核双重共振谱自由基的检测手段和仪器35ESR:ElectronSpinResonance自由基波谱特征有未成对电子的顺磁性未成对电子在磁场中有两种可能的能态：其能量差E随外磁场的增加而增加E=h=gH光谱分裂因子玻尔磁子外磁场强度当外场符合上述关系时即发生能量吸收产生磁能级间跃迁(Landegfactor)36自由基波谱特征有未成对电子的顺磁性未成对电子在磁场中有两种可（负电荷电子）电子自旋量子数+1/2或-1/2未成对电子无外场时自旋是随机无顺序，宏观无磁性未成对电子有外场时自旋要分裂，态（低能量）：-1/2对应磁矩与外场（H0）方向相同态（高能量）：+1/2对应磁矩与外场（H0）方向相反37（负电荷电子）电子自旋量子数未成对电子无外场时自旋是随机无顺eH0eh/2mcms=-1/2ms=+1/20H0:外场强度g:磁旋比=磁矩/电子角动量自由电子：2.002319e:波尔磁子9.2732x10-24J/T38eH0eh/2mcms=-1/2ms=+1/20H0SimilartoChemicalShift,CouplingConstant,areaamount,andspiltinfo.ofHNMR,usedtopredict/determinethestructureofcompounds,ESRinfo.canbeusedtocheckthestructureinfo.Offreeradicalstoo.Position,strength,hyperfinesplitconstant(位置，强度，超精细分裂常数得到自由基结构信息）39SimilartoChemicalShift,CouFormostorganiccompounds:g=2.0022.006(inHNMRasChemicalshifts,对等于核磁中的化学位移)dependingontheelectronicenvironmentoftheunpairedelectron(lessusefulthanHNMRbecauseoflittledifference)40Formostorganiccompounds:TwoimportanthyperfinespilttingHat-CarbonandUnpairedElectronHat-CarbonandUnpairedElectronlongdistanceeffectisverysmaller(SOrbitofHon-CmayhavehyperconjugationwithUnpairedelectron43CouplingConstantofhyperfineTheInteractionbetweentheUnpairedelectroncouplingwiththeneighborednuclearspin(核自旋）1H,13C,14N,19F,31P,35Clwillgivethehyperfinestructure(精细结构）spiltting,fittothe（n+1)(2nI+1)ruleusedinHNMR.44TheInteractionbetweentheUnCH3.:1:3:3:123.0GspinSlightexcessofspinHSlightexcessofspin45CH3.:1:3:3:123.0GspinSlighCH3CH2.Protonspitthesignalto4,thenProtonspilttoitto3,total3x4=1226.9G22.4Ga=-2.24mT(2H)a=+2.69mT(3H)偶合常数46CH3CH2.Protonspitthesigna()()()Thesplitconstantainthehyperstructurewillgivespecialinfo.ofthefreeradicalstructureaH=22gaussaH=25gauss47()()()ThesplitconstantaESR:verysensitive:10-9McanbecheckedhighlyreactiveHowtoincreasetheconcentrationofradical1),heatingorphototoproducetheradialwithoutstop2),adjustthereactioncondition,slowdownorstopthereactionofradical(Matrixtech:mixedtheresourceofradicalwithsolventorinertgas,coolingittothesurfaceofcoolant,heatingwithlighttoproduceradical3),capturethespincompoundsbyadditionofotherreactantstoreactwiththeradicals48ESR:verysensitive:10-9Mcan-FreeRadical:unpairedelectroncouplingwithalltheconjugatedHinthesystemsimpleESRbecauseallHareequals.n+1peaks(n:amountofsameH)环戊二烯自由基苯负离子自由基0.375mT49-FreeRadical:unpaiTriplet(三线态）2unpairedelectronsXYZS:singlet50Triplet(三线态）2unpairedelectrZeroFieldSplitting(零场裂分）无外场时三态能量有差别51ZeroFieldSplitting(零场裂分）无外场时