Awesome Doublet of Quartets

The other day, our newest group member was taking an NMR of a reaction mixture that contained triethylammonium chloride. What I found so interesting was that the methylene signal was very well-resolved, showing a clear doublet of quartets. This could only happen if the N-H was also coupling to the methylene.

Nuclear Magnetic Resonance spectrum of the methylene of triethylammonium chloride showing a quartet of doublets

The J-coupling to the N-H is 4.85 Hz, and the J-coupling to the methyl is 7.37 Hz. Maybe I should be calling it a quartet of doublets?! Great teaching moments ahead!

I’ve attached the data from our Bruker instrument as a ZIP file. This is a reaction mixture, so be warned, it is impure. 1,2-dimethoxyethane is the other major species in the spectrum.

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