Chemical shift information offers a clue into an atom’s hybridization state. For example, carbon atoms with a carbon chemical shift greater than 90 ppm are typically considered as sp2 carbons. If 4 sp2 carbons are present, one can infer 2 alkene pairs. Five sp2 carbons and an available oxygen and nitrogen atom suggest the possibility of a pyridinone fragment.
The example below shows a 5 sp2 carbons and 2 sp3 carbons, coloured pink and blue, respectively. The chemical shift at 167 ppm for the quaternary carbon suggests the presence of an amide group.
Using the information described above, a set of 6 possible candidate structures can be pieced together.
I need your expertise for explaining 1H nmr of my compound..my compound is a pyrdinone compound with imidazole substiutent..surprisingly, i find all the imidazole protons as singlets..why is it so? Please explain this unsusual pattern
ReplyDeleteI received your comment on my blog. FID processing, data acquisition, temperature, concentration, etc. can influence the displayed coupling pattern. Without FID data to examine, I cannot be certain which scenerio is applicable.
ReplyDelete