Sciencemadness Discussion Board

Second-order NMR splitting

Metacelsus - 9-12-2016 at 08:27

Can anyone identify this pattern? It showed up in the spectrum of a side product of one of my reactions, and I haven't seen anything like it before. (The spectrum was taken in CDCl3 at 400 MHz).


Edit: These peaks are almost certainly from 2 different compounds.

strange splitting.png - 35kB

[Edited on 12-10-2016 by Metacelsus]

Eddygp - 9-12-2016 at 09:36

I was expecting a doublet of a doublet... but this.. Wow!!
H MNR I guess, yes?

Is there any F, P or some other NMR active element in your sample? (apart from H, but that can couple to H)

Metacelsus - 9-12-2016 at 13:06

No, it's just H, C, O, and S. I'm starting to think that it might just be two unrelated pairs of doublets from an impure sample.

DJF90 - 9-12-2016 at 14:58

Sure looks that way

Metacelsus - 9-12-2016 at 17:26

Yes, it's definitely at least 2 compounds. Originally, it was 1 peak on the MPLC, but I changed to a better eluent, and it came off as 2.

DJF90 - 10-12-2016 at 00:21

Glad to hear you resolved the issue.