[Babcock_Hall]

We distilled a small volume of triflic anhydride using a short path distillation apparatus with a ground glass thermometer with a fixed length this morning and collected four cuts in all, and none of them were near the boiling point, which is 81-83 °C.  Instead they were in the general vicinity of 60 °C.  It may be that the placement of the thermometer was not ideal to represent accurately the temperature of the vapor.  The remaining distillant looked darker and may have had some brown or black material in it.  I seem to recall seeing this some time ago.

When we took the ¹³C spectrum, we saw a quartet near 120 ppm (which is expected), but we also saw other peaks, such as one at 5.6 and one at 71.0 ppm.  The ¹H spectrum showed a broad peak around 9.6 ppm, a non-first order pattern (AB?) around 4.22 ppm and a singlet around 1.26 ppm.  When we examined the fourth fraction, it looked cleaner by ¹³C, and the peak around 4.22 looks like a regular singlet.

I am puzzled by the NMR results.  Can someone help us explain them?  Are there other tests for whether or not the triflic anhydride is good?

EDT
The H-1 shift for methyl triflate is 4.21 ppm, and the C-13 shift is 61.7 ppm, according to Hans Reich's site.  Our H-1 matches this nicely, but we see signals around 54 ppm and/or 70 ppm in the carbon spectra, but perhaps only a small signal in the low 60s.

[TheUnassuming]

Where did you get the triflic anhydride you are distilling?

Methyl triflate?  So either methanol got into your system or its some byproduct of how the triflic anhydride was made? Do some of the other peaks you see correspond with triflic acid?
Whats confusing me is that MeOTf has an even higher boiling point than the anhydride, so you would expect it to be more in the final fraction which in your case is the cleanest fraction of anhydride! 

[Babcock_Hall]

Thank you.  I agree about the boiling point of methyl triflate, and I don't have a good candidate for anything which might boil at a lower temperature.  I don't see how we could have introduced methanol into the bottle.  There is a broad downfield signal that is about 9.6 ppm in one spectrum and roughly 11 ppm in the other spectrum.  That might be the signal from an acid, but I am not certain.  We purchased it from Alfa Aesar.  We have an unopened bottle from TCI, which we may use tomorrow.
EDT
One problem that we face is that the ¹³C chemical shift of the CF₃ group does not seem all that sensitive to the rest of the molecule.

[TheUnassuming]

I wonder how they make it on large scale?  It seems most likely its some impurity based on the synthesis, but thats kind of a copout.
 
If you are running your NMR in benzene the proton of 4.2 and carbon at 54 is probably DCM.

The proton at 1.26 makes me think you might have grease in your sample, but usually with that you will see a carbon signal in the ~30 range. 

It's very interesting that the CF₃ carbon doesn't have a distinguishable shift from anhydride to OMe.

Hopefully its just a bad bottle and the TCI you open today will be good! 

[Babcock_Hall]

Thank you.  We ran the NMR in CDCl₃.  There is a bit more color in our reaction than usual, but we won't know until the end of the day how it turned out.