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Chemistry Forums for Students => Organic Chemistry Forum => Organic Spectroscopy => Topic started by: el quimo on December 15, 2015, 04:13:49 PM

Title: Broad singlet in 13C NMR ???
Post by: el quimo on December 15, 2015, 04:13:49 PM

 I get a broad singlet at 47.3 ppm in a 13C spectrum.  A HMQC revealed it correlated with a broad peak at 3.5 ppm.  Has anyone seen something like this before?

I am attaching COSY and HMQC.  Thanks.

Title: Re: Broad singlet in 13C NMR ???
Post by: ATMyller on December 16, 2015, 07:54:50 AM

What solvent are you using?

A CH₂ next to amine group or solvent impurity perhaps.

Title: Re: Broad singlet in 13C NMR ???
Post by: Irlanur on December 16, 2015, 08:44:07 AM

So what exactly is the question? it is just some sort of exchange phenomenon.

Title: Re: Broad singlet in 13C NMR ???
Post by: el quimo on December 16, 2015, 12:06:04 PM

I figured it out.  It's two CH2s that have hindered rotation due to some nearby tertiary amines.