I think I have figured out the IR spectrum for benzophenone. Would it be that the sharp peak in the middle (1700 cm^-1) is for the ketone and the little peaks past the 2900 cm^-1 range are the sp2/sp3 carbons from the benzene rings?

IR spectrum of Benzophenone

I have an H-NMR spectrum for the same compound. I know there are only three peaks because the compound is symmetrical. However, I am confused about determining the J values for each hydrogen.

H-NMR spectrum of Benzophenone

Can someone kindly assist?

  • $\begingroup$ If you print expanded portion with the resonance in Hz, you can easily calculate J values. $\endgroup$ May 7, 2020 at 20:08
  • $\begingroup$ Can you explain what you mean? $\endgroup$
    – Boo
    May 7, 2020 at 20:11
  • $\begingroup$ Your peaks in the main spectrum is in $\pu{ppm}$. You have to print it again in $\pu{Hz}$ (there is a option to do so in printing software). Then expand it to be more clear. It is hard to read and isolate in compact mode. $\endgroup$ May 7, 2020 at 20:15
  • $\begingroup$ Oh...I had to screenshot this photo because I was unable to save it correctly especially since it was given to me as a cropped photo. Because of this, I was wondering if I can figure the J values another way $\endgroup$
    – Boo
    May 7, 2020 at 20:26
  • 2
    $\begingroup$ Why do you want the J couplings? The assignment of all peaks is totally clear without, and the two triplets are higher order peaks anyway, so analysing the coupling is not trivial. $\endgroup$
    – Karl
    May 7, 2020 at 22:56


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