Looks perfectly reasonable to me. Off resonance decoupled spectra are run so you can work out how many hydrogens are attached to each carbon. A fully decoupled spectrum has J-1, J-2, and J-3 coupling, hence unless it's a compound with few hydrogens (heteroaromatics for example) the spectrum becomes unusably complex. Off-res decoupled just shows the J-1 coupling so a CH3 shows up as a quartet, a CH2 as a triplet, a CH as a doublet and a carbon without hydrogens as a singlet. TMS is obviously going to be a quartet, but it's out of the way so that doesn't matter. By the way, CDCl3 continues to show up as a triplet - do you know why?
Sorry, maybe I hadn't made my knowledge on the spectra clear. I understand clearly why the carbons have different peaks, and differences between fully decoupled and off-resonance decoupled spectra, etc. I realize that CDCl
3 gives a triplet of equal heights (if I remember correctly, it has something to do with the
2H having a spin of 1 instead of a 1/2 like
1H). I was hoping people could offer their insight/opinions on some aspects of the spectra. In order to narrow the scope of my "Help me interpret these spectra question" (which I've read is something to aim for), let me put a little list of some of the aspects that are giving me the most difficulty.
For the first spectra:
1H NMR
-The splitting is so incredibly confusing. I've looked at the blowup to the left of the peaks, and there is clearly some sort of ____ of doublets, or something causing the strange splitting pattern, but I've no clue as to what.
C13NMR
-There are two messy peaks in the off-resonance spectrum. Are those 2 separate carbons that are just very similar? Or is it one, and it's just...messy.
-Off resonance again, down by 0ppm, is that the two middle peaks of the TMS quartet?
-Decoupled spectrum, there are two peaks, one at 85, the other just below 100, ignore those? Are they part of my compound?
For the second spectrum
1H NMR
-I know that irradiating a particular hydrogen isolates from coupling with any other hydrogens. This allows us to more closely look at the various coupling and helps figure out what hydrogens are coupled to eachother. However, I'm struggling to see the difference, if there is any for most the irradiation inserts. The only one that really jumps out is the circled one, on the bottom left. It's pattern is different compared to the other irradiations on that side. The irradiation in the middle, of the peak at 4.2, shows no (?) change. I suppose one could argue that it appears the irradiation at the top (of 1.2) has a lower coupling constant that the middle irradiation (of 3.55), but I'm not sure.
C13 NMR
-I assume the peak at 0ppm is TMS. At 65 ppm, I would imagine that is 2 carbons, ya?
Hopefully, that'll help narrow the spectrum of things to discuss, and allows people to focus on what parts I'm truly confused about. Basically, I fully understand what the different spectra are, and how to use them, and for the most part, how to interpret them. I've got many more in this packet, that I did not need to post about, because I was able to handle them, these are the 2 that I'm stuck on.
Thanks again for any insights!
-Mac