NMR Coupling Constants, Chemical Shifts, Carbon NMR and Practice

[@Chavat212]

Great and very useful thanku so much

[@brillianaviasafitri602]

Thanks, Sir. It's very helpful.

[@henryarias256]

Great lecture!

[@maroonhorizon1693]

Amazing wow thank u

[@sucharitadey307]

my question is in CFHCH2 Ha gets split by Hc trans so Jac is wide, but I am confused how each it got split in 4 lines ? I mean one line into two by Hb

[@JeffreyEngle]

You can break it down into two parts. Ha is split by Hc into a large doublet, and then each "arm" of that doublet is further split by Hb into two smaller sets of doublets (called a doublet of doublets). I hope that helps!

[@sucharitadey307]

+Jeffrey Engle Thank you. doubt is cleared. Sir I was asking do we get some specific J values for trans coupling like Ha and Hc, cis coupling Ha and Hb and other types like vicinal types.. if so can you provide a chart please.

[@JeffreyEngle]

It can vary a little bit depending on the situation (i.e. whether or not there are electron donating or withdrawing substituents) . Typically protons that are trans to one another have coupling constants that are around 16 Hz while protons that are cis are around 10 Hz. If you are looking for specific reference values I would check out the web page by Hans Reich at the University of Wisconsin Madison. Main NMR Page: www.chem.wisc.edu/areas/reich/chem605/index.htm Vicinal 1H Coupling: www.chem.wisc.edu/areas/reich/nmr/05-hmr-05-3j.htm

[@sucharitadey307]

+Jeffrey Engle Thank you so much