# The IR/ H-NMR analysis of benzophenone?

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 pass 2900 cm^-1 rang are the sp2/sp3 carbons from the benzene rings?

Also, I have an H-NMR spectrum for the same compound and I know there are only three peaks because the compound is symmetrical. But I am confused on how to determine the J values for each hydrogen.

Can someone kindly assist?

• If you print expanded portion with the resonance in Hz, you can easily calculate J values. – Mathew Mahindaratne May 7 '20 at 20:08
• Can you explain what you mean? – Boo May 7 '20 at 20:11
• 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. – Mathew Mahindaratne May 7 '20 at 20:15
• 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 – Boo May 7 '20 at 20:26
• 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. – Karl May 7 '20 at 22:56