[理学]Chapter 36 2D NMR核磁.ppt

* * Chapter-3(6) 2D-NMR Spectroscopy Marine College, Shandong University at Weihai, 2011 Frequency and intensity axes in a typical ID-NMR spectrum. 1D-NMR The basic theory of 2D-NMR spectroscopy A simple 1D-NMR Experiment A Muhipulse 1D-NMR Experiment A simple 2D-NMR Experiment The basic theory of 2D-NMR spectroscopy The chloroform signal recorded with variable evolution time. 2D NMR 谱图常以轮廓图表示而不用三维的方式. 相同情况同样使用在地图上 10 20 30 40 50 60 20 40 60 0.5 1 1.5 2 10 20 30 40 50 60 10 20 30 40 50 60 1H-1H COSY: Homonuclear correlation spectroscopy HMQC: Heteronuclear multi quantum correlation spectroscopy HMBC: Heteronuclear multi bond correlation spectroscopy NOESY: Nuclear overhause and exchange spectroscopy 2D-INADEQUATE: Incredible natural abundance double quantum transfer experiment 2D-NMR Spectroscopy 1H-1H COSY: Two- dimensional homonuclear correlation spectroscopy 1H d ppm 1H d ppm dA dX A,X X,A X X A A d d d d A1 A2 X1 X2 AX spin system: 2D 1H-1H COSY experiment symmetrization of cosy data strong F1 noise of CH3 Horizontal F1 = 0 axial peaks 1H-1H COSY: Two- dimensional homonuclear correlation spectroscopy ? 1H-1H COSY谱中的相关峰表示与该峰相交的两个峰之间有自旋－自旋偶合（J－Coupling）存在。 cross peaks 8 6,8 8 7,8 6,5 7 6 13 14 12 11,5 7,6 13,14 13,12 11,12 dH dH 相关峰的强弱（高低）与偶合常数J值的大小有关，J值越大相关峰越强 有没有相关峰，只取决于有没有J偶合，并不在乎相隔的化学键多少。 当偶合常数（J值）很小时，一维谱上可能表现不出峰的偶合裂分，但二维谱上仍可能表现出相关峰 TOCSY: 1D selective TOCSY: Selective TOCSY spectra, H-1 irradiated, different mixing times 1D selective TOCSY: NOESY 1D selective NOESY = NOE 差谱 NOE is based on the fact that if one nucleus is selectively irradiated, the signal intensity of the neighboring nucleus will change (in most cases it will be increased). NOE difference spectrum 200 MHz 1H-NMR spectrum of dibromo compound and its NOE-Dif spectrum after irradiation at the resonance frequency of cyclopropyl proton. Example: HETCOR: Two-dimensional heteronuclear correlattion spectroscopy: HMQC HMQC实验是异核二维谱，没有对角线峰。每个相关峰表示相交的氢、碳峰所对应的氢、碳原子是直接（一键）相连的。 HMQC实验可以使氢谱和