无机物理方法核磁共振部分省公共课一等奖全国赛课获奖课件.pptx

The Physical Methods in Inorganic Chemistry (Fall Term,)(Fall Term,)Department of ChemistryNational Sun Yat-sen University無機物理方法（核磁共振部分）無機物理方法（核磁共振部分）Chapter 5第1页BasicTwo-DimensionalExperimentsWhy multi-dimensional?ResolutionMulti-quantum coherencesCoherence transferTypes of multi-dimensional spectra:To CorrelateTo Resolve To Exchange(Diffusion)第2页From1Dto2D,3Dt2t1第3页If you look at the same data matrix in a different way.You also get a series of FIDs.第4页In either direction,you see FIDsIn either direction,you see FIDsYou really dont know which is“acquisition dimension”,Do you?第5页A2DSpectrumt2t1FT2FT1F2F1第6页2DFT第7页第8页Typical2DLineshapes第9页ResolutionThe resolution in the second dimension is determined the same wayas in 1D NMR.The resolution in the first dimension is determined by the longest evolutiontime in the first dimension(maximum of t1).The total evolution time in the indirect dimension is equivalent to the total acquisition time in the detection dimension.第10页第11页第12页第13页F1F2Acquisitionanddataprocessing:第14页第15页COSYpulsesequence(top)withapresaturationpulsetosuppresswatersignal.Alsoshowninthediagramarethecoherencetransferpathway(middle)andphasecyclingscheme(bottom).PresatPresatt1t2p=+1p=0p=-1第16页第17页第18页COSYpulsesequence(top)withapresaturationpulsetosuppresswatersignal.Alsoshowninthediagramarethecoherencetransferpathway(middle)andphasecyclingscheme(bottom).PresatPresatt1t2p=+1p=0p=-1第19页第20页第21页第22页RecollectingChapter2第23页FourbasiclineshapesAnti-phase absorptiveIn-phase dispersiveAnti-phase dispersiveIn-phase absorptiveFT Real partFT Real partFT Real partFT Real part第24页A2Ddispersivepeak第25页A2Dabsorptivepeak第26页第27页+-+-+-+-+-+-+-+-第28页第29页Absorptive cross peaksDispersive diagonal peaksDispersive cross peaksAbsorptive diagonal peaks第30页Absorptive cross peaks第31页Absorptive cross peaks第32页Dispersive diagonal peaks第33页ABCDF E第34页第35页12534678910第36页132967 4851012534678910第37页AbsoluteValueDisplay第38页The major drawback of COSY:cross peaksnear the diagonal line may be obscured by diagonal peaks.第39页第40页第41页DQFCOSY第42页12534678910第43页12534678910第44页第45页第46页TheAdvantagesofDQFCOSY Having the same phase for both the diagonal and cross peaks;Because the magnetization is detected in anti-phase,the multiplet structure isretained with opposite phase.In other words,the two lines of a doublet are 180 out of phase with respect to each other.While this can lead to cancellation in crowded regions of the spectrum,it also allows for the easy identification of multiplets(based on their square,or box,shape),and for measuring the size of the scalar coupling constant connecting the two spins.Another advantage of the DQF-COSY experiment is not so immediately obvious.In orderfor a transition to create multiple quantum levels,and to survive a multiple quantum filter,you need to have at least two spins or three spins for a 2Q or 3Q transition,respectively.Thus,singlets are drastically reduced in intensity in a DQF-COSY spectrum.第47页TheDisadvantagesofDQFCOSYThere are also disadvantages to the DQF-COSY relative to COSY.First,the sensitivity of DQF is about a factor of two lower than regular COSY.Second,MQ relaxation in 1Hs is very slow,so the experiments require a relatively long d1 relaxation delay.Thus,while a good COSY spectrum could be generated in about 2-4 hours of data accumulation,a good DQF-COSY requires about 16-24 hours to allow complete relaxation during d1.第48页第49页第50页第51页TOCSY region of amide protons from residues Lysine 29 and 48第52页TOCSY of BPTI at different pressures第53页TOCSY of BPTI at different pressures第54页COSYFamilyCOSYCOSY-45,COSY-90R-COSY(LR-COSY)pQF COSYPE-COSYE-COSYMQ COSYTOCSYzCOSY,zzCOSY,J.R.COSY.第55页3JHN=5.9cos2-1.3cos+2.23J=9.5cos21-1.6cos1+1.8 第56页JCouplingMeasurementJ coupling and peak intensityJ coupling and linewidthJ coupling and overlap第57页BasicHeteronuclear2DExperimentsIntroductionHeteronuclear correlation(HETCOR)and its variants(COLOC,HMBC etc)Heteronuclear multiple-quantum coherence(HMQC)Heteronuclear single-quantum coherence(HSQC)第58页IntroductionTheavailabilityofother(“hetero”)nucleithanprotonformulti-dimensionalNMRspectroscopyisextremelyuseful,particularly,formacromolecules(ofsyntheticorbiologicalorigin)becausetheconnectivitybetweenprotonsandheteronuclearspinscanbeestablishedinadditiontothehomonuclearmulti-dimensionalspectra.Likehomonuclear2Dspectroscopy,thecentraltaskinheteronulcear2Dexperimentsistoselectpropercoherencepathwayssothatthedesiredinteractioncanbeelucidated.Heteronuclear2Dexperimentscanbemorediversebecause,e.g.,thedataacquisitioncanbecarriedoutonheteronuclei(C-13,N-15etc)oronprotons(inversedetection).第59页第60页第61页Heteronuclearcorrelation(HETCOR)anditsvariants第62页During t1,the carbons that are coupled to protons are selected so that only those carbons are“visible”in the detection period.The choice of two fixed delays 1 and 2 is determined by smallest J-coupling we want to observe,i.e.,when long-range coupled carbons(in addition to directly bonded carbons)are also to be observed:1=1/2Jmin,2=1/3Jmin.第63页EnhancedHeteronuclearCorrelationS(I,S)IS第64页第65页第66页COrrelationviaLOng-rangeCoupling(COLOC)The choice of two fixed delays 1 and 2 is determined by smallest J-coupling we want to observe,i.e.,when long-range coupled carbons(in addition to directly bonded carbons)are also to be observed:1=1/2Jmin,2=1/3Jmin.第67页第68页HeteronuclearMulti-BondCorrelation(HMBC)第69页第70页第71页第72页第73页InverseDetection第74页HSQC 第75页第76页Points a-d(INEPT)第77页Points e-g(Reversed INEPT)第78页PhaseCycling第79页第80页第81页第82页第83页 HMQC第84页第85页第86页第87页第88页第89页第90页第91页DifferenceofHMQCandHSQC(I)第92页DifferenceofHMQCandHSQC(II)第93页2DJSpectroscopy2Dmethodsthatshowcouplingmultipletsversuschemicalshift.Thereisbothahomonuclearandaheteronuclearversion.Bothmethodsareusefulforresolvingoverlappingmultiplets.Theyarealsousedtomeasurecouplingconstants.ThesesequencesallowbothJcouplingandchemicalshiftevolutionbutre-focusthechemicalshiftslikeaspinechosequence(90-180-acq).第94页t1:J;t2:J+CSt1:JIS,t2:JIS+CSS第95页第96页第97页第98页第99页SummaryHETCOR,COLOCHSQC/HMQCHMBCJ spectrosc.HSQC is now a“platform”for many more complicated pulse sequences.第100页第101页