I've noticed that peaks from CH3 groups, especially CH3 groups attached to aromatic rings, are shorter than other peaks (CH and CH2) that represent the same number of carbons. I'm not sure if this is a T1 or a T2 effect (I'm using a very short relaxation delay). I'm guessing that it's a relaxation difference due to the rapid rotation and equivalence of the CH3 protons, but I'd like a more detailed explanation of what's going on. But not too detailed, I'm not a physicist!
Thanks,
Neil
Neil E. Jacobsen, Ph.D.
NMR Facility Manager
Department of Chemistry and Biochemistry
University of Arizona
1306 E University Blvd.
Tucson, AZ 85721
520-621-8146
Received on Thu Jan 31 2013 - 09:17:35 MST