Piecing It All Together

As we ve mentioned before, the interpretation of NMR spectra is often made complex by the sheer quantity of information that you are confronted with. This is every bit as true for carbon NMR as it is for proton and when you combine the two, that huge pile of information just gets bigger... More important still then that you approach the pile in a logical, methodical manner. 

Once your problem takes on a 13 C dimension, you are of course, obligated to examine the 13 C data with the same level of dispassionate scrutiny that you apply to the proton data. Chemical shifts cannot be fudged and unexpected peaks cannot be glossed over. You have to be able to account for everything you see to have confidence in your product. 

As with proton interpretation, this must be considered an iterative process. Try to shoot your proposed structure down. Don t be afraid to tear it up at any stage and start again if some glaring problem becomes apparent. Resist temptation - don t hammer the square peg into a round hole This is why we do spectroscopy in the first place. If it crashes and bums then it was wrong so shed no tears. If it survives then it s got a good chance of being a winner. Finally, go back again and check that there is no mismatch between any carbon data and any supplementary proton data, e.g., NOE experiments. 

When it all sits happily or can at least be explained, the job is done as well as it can be. Not before. 

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The archive is important because it provides context for work—not merely a way of getting at a particular known piece of work. Libraries provide that context by bringing together the patchwork of various pubUshers and models, and then deal with the frustrations of trying to piece it all together. Libraries work toward a grand vision of a richer and more interoperable context. Gold said. 

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