I did a search on here but couldn't find this particular topic. In my Organic Chemistry 2 lab we did an H NMR (among other analysis) for acetylferrocene. The spectrum shows a peaks at 2.4, 4.2, 4.45, and 4.75ppm and I've assigned them with 3H, 5H, 2H and 2H respectively. I know the singlet at 2.4ppm is from the methyl group on the first aromatic ring, and the singlet at 4.2ppm is from the 5 equivalent H on the second aromatic ring. So my question is how do I tell which Hydrogens (the 2 closest to the substitution (labeled "a") or the 2 furthest from the substitution(labeled "b")) represent each signal? My lab requires me to choose which specific H goes with each signal but from searching online for the past week I got the feeling its not within Organic chemistry 2 lab to be able to separate these. I was thinking maybe it had something to do with resonance but I'm pretty confused at this point. I ran across the very same problem when assigning peaks to symmetric 6-membered rings because "the closer to the electronegative group = more downfield" doesn't seem to work for aromatics (according to my TA but that's all the help he offers).