May 26, 2009
Misconstrued coupling patterns on a 1H NMR spectrum can halt an elucidation process in its track. As such, structural connectivity is best validated with additional data such as a 1H-1H COSY.
A good use of coupling patterns and coupling constants is at the end of the elucidation process. Candidate structures can be verified or eliminated by the use of coupling information.
The following coupling patterns are some examples where the observed coupling pattern is not as simple as tallying the number of observed lines.