lecture-6---HSQC-&-HMBC

1H-HeteronucleiCorrelationSpectra1H-HeteronucleiCorrelationSpectraHMQC检测高灵敏度核，如1H,19F,31P（反向检测）单键耦合多用于1H－13C稳定，受实验误差影响较小HSQC检测高灵敏度核，如1H,19F,31P（反向检测）单键耦合分辨率高于HMQC受仪器设置和实验误差影响较大HMBC检测高灵敏度核，如1H,19F,31P（反向检测）多键耦合多用于1H－13CHETCOR检测低灵敏度核，如13C，单键耦合f2方向分辨率高异核相关谱没有对称性，也没有对角线峰。CoherenceTransfer(相干转移）t1之后的脉冲将一个核上的磁化量转移到与之相耦合的另一个核上，这种过程称为Coherencetransfer.ThroughbondsscalarcouplingThroughspacedipolarcouplingThroughphysicalorchemicalexchange90x90yt1t2Sameas1Dexperiment90ºpulseTransfersbetweencoupledspinsCoherenceTransfer(相干转移）Sensitivityof1H-HeteronucleiCorrelationSpectra∝NAT-1T*2(NS)1/2signaltonoiseratioB03/2N：所观测样品中的分子数量A：所观测核的天然丰度gexe：所激发核的磁旋比gobs：所检测核的磁旋比T*2：有效横向驰豫时间NS：累积扫描次数所激发核所检测核Sensitivityof1H-HeteronucleiCorrelationSpectraHXHXHXHXTheoreticalRelativesensitivity1H-31P1H-13C1H-15N1112.541048301032300CH2和CH3又多2倍和3倍的理论灵敏度HeteronuclearMultiple-QuantumCorrelation(HMQC)P1:质子的激发D:质子根据1JCH的不同而发生变化P3:使质子和碳和之间发生相干HeteronuclearMultiple-QuantumCorrelation(HMQC)HMQC是1H检测的直接的异核化学位移相关谱。F2维代表1H的化学位移，F1维代表13C的化学位移，所给出的信息与直接检测的CH-COSY谱基本相同。在实验时可采用13C去偶和不去偶两种方式。采用13C去偶时，13C，1H的交叉峰只出一个。无13C去偶时，13C，1H的交叉峰出两个，即受13C的偶合作用，与其相连的1H在F1维（13C方向）分裂成两个峰，两峰的距离即是13C，1H偶合常数。图谱中没有对角峰，只给出表示直接成键的C—H偶合关系的交叉峰。每一个交叉峰代表水平和垂直线上对应化学位移的质子和碳之间的直接连接关系.HeteronuclearMultiple-QuantumCorrelation(HMQC)1-(4-Vinylbenzyl)piperazineHeteronuclearSingle-QuantumCorrelation(HSQC)HMQC中1H－1H耦合造成谱图质子方向分辨率的降低。HSQC中X核的变化过程中不受质子之间耦合的影响，从而得到质子分辨率更高的谱图。HeteronuclearSingle-QuantumCorrelation(HSQC)GRASP-HSQCHeteronuclearSingle-QuantumCorrelation(HSQC)HeteronuclearSingle-QuantumCorrelation(HSQC)HMQC，HSQC：质子和碳的连接在第二维分开在一维中重叠的峰；辨识同碳上的质子；不进行13C的扫描而获得有关13C谱的部分信息HeteronuclearSingle-QuantumCorrelation(HSQC)723.45501.10451.950.98351.650.85321.45262.20231.620.95220.95210.95160.80HeteronuclearSingle-QuantumCorrelation(HSQC)723.45501.10451.950.98351.650.85321.45262.20231.620.95220.95210.95160.80HeteronuclearSingle-QuantumCorrelation(HSQC)，CoorperatedwithCOSY321.45262.20HeteronuclearSingle-QuantumCorrelation(HSQC)HeteronuclearSingle-QuantumCorrelation(HSQC)CyclosporineHeteronuclearSingle-QuantumCorrelation(HSQC)soybeanleghemoglobinHMQCvsHSQCTheHMQCversionhastheadvantageofhavingfewerpulses.Thismakesitlessinsensitivetopulsecalibrationerrors.Especiallyimportantisthelackofany180°13Cpulses,whichtendtobeprettymuchoffattheedgesofalarge13Cspectralwindow,evenwhenproperlycalibrated(on-resonance).However,theresolutioninthe13Cdimensionislimitedbythe1Hmultipletpattern,whichcanbeupto30-40Hzbroad(dependingonthe1Hspinsystem),whiletheresolutioninanHSQCexperimentisonlylimitedbythe13Clinewidths.HeteronuclearMultiple-BondCorrelation(HMBC)显示二键，三键耦合确定C－C连接顺序HMBC谱是1H检测的远程的异核化学位移相关谱。HMBC实验可以不用13C去偶的方式，因为远程13C，1H之间的偶合常数较小，在数字分辨率较低的情况下（二维谱的数字分辨率均大大低于一维谱）几乎显示不出裂分的效应。同时可以区别直接偶合的13C，1H相关峰。它们在HMBC谱中受13C的偶合而产生裂分。HeteronuclearMultiple-BondCorrelation(HMBC)HeteronuclearMultiple-BondCorrelation(HMBC)HMQC对HMBC的干扰HeteronuclearMultiple-BondCorrelation(HMBC)1.761.451.630.952.062.861.191.282.232.372.114.974.862.601.471.431.010.9826.650.159.138.429.316.463.029.229.5112.0151.048.039.133.322.6HeteronuclearCorrelation(HETCOR)检测低灵敏度核，如13Cf2方向分辨率高，多用于13C相当拥挤的情况下HeteronuclearCorrelation(HETCOR)HeteronuclearCorrelation(HETCOR)INADEQUATEIncredibleNaturalAbundanceDoubleQuantumTransferExperimentCOSY5mg30minHSQC10mg2hHMBC10mg5-10hHETCOR20mg6-12hINADEQUATE100mg24-72hINADEQUATE直接相连的两个13C出现在相同f1的位置上。相关峰的连线的中心点在一条直线上。当相邻碳的化学位移值非常接近时，交叉峰消失而裂分为多重峰INADEQUATE41211151465192310