如何分析1H和13CNMR图谱 (Reading NMR Spectra)？ [内容包括： How to Read a Carbon NMR How to Read a Proton NMR 英文版，不难阅读，有兴趣者不妨看看，定有收获。 http://academics.keene.edu/rblatchly/OrgoCommon/hand/Spectroscopy/nmr/ReadNMR.pdf How to Read a Carbon NMR 1. Establish what type of spectrum you are looking at (broadband decoupled, gated decoupled, DEPT, etc.). 2. Note and count the number of peaks. Remember to ignore solvent peaks (there may be several of them). 3. Group peaks into rough ranges (C=O, C=C, C-X, C-H). Look at patterns within ranges. For example, the number of peaks in the aromatic region may be very informative. To analyze the spectrum of a known compound: 4. Predict the number of chemical environments from the structure. 5. Verify that you have the correct number of peaks. This is easy and informative. Go back to 2 if necessary—did you miss a small peak, or accidentally count the solvent? It’s possible that two carbon peaks are superimposed, but it’s unlikely. It may be that you overlooked some element of symmetry, and predicted more peaks than there are. 6. Assign peaks to specific carbon environments to the best of your ability. It is common for you to be able to assign only some of the peaks. Others might have to be grouped, if they are too similar. Draw a bracket over similar peaks, and refer to the structural environments as a group. 7. Verify that there is one peak per environment. For an unknown compound 8. Collect other data and constraints. Molecular weight? Functional groups present? Without this, it’s unlikely that you’ll be able to solve the structure. 9. Consider substructures (especially when you have a DEPT spectrum). 10. Imagine different ways that substructures can be assembled. Try to support or exclude your assemblies. ......... 查看更多0个回答 . 4人已关注
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