Thread: How do NMR tell the conformation of a molecule?
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Unread 12-24-2005, 09:26 PM
Ensur Ensur is offline
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Default How do you use NMR to tell the conformation of a molecule?
Which NMR are you looking at? C13 or H1?I'm most familiar with H1. What I do is just read each signal at a time. First, if I'm given the compund, I'll calculate the index of hydrogen deficiency to tell me if I have any crazy double or triple bonds or aromatic compounds.Then I'll count how many unique signals I have. And then I'll take it one at a time. If one of the signals is a 3H doublet, I can draw a C with 3 H's on it, and a second C connected to that C, with 1 H on it since the reading is a doublet (remember coupling).I wish I could help you out with 13C but, don't quite remember it as well.As for chemical shifts, http://wwwchem.csustan.edu/Tutorials/NMRTABLE.HTM will tell you what kind of substrates produce which chemical shifts. Best thing to do is just memorize them.

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