[zmasterflex]

I recently completed a lab assignment for an unknown material. I narrowed it down to Benzonitrile and 2-Tolunitrile. The H NMR spectrum that I was given has peaks around 7.6ppm integrated for 5H. This suggest Benzonitrile because the 2-Tolunitrile would have a 3H peak somewhere upfield. The IR that I was given exactly matches the Benzonitrile IR and I'm pretty sure that is my compound. The question I have is, what would the difference be in the IR between the 2 compounds? How would the methyl group ortho to the nitrile affect the IR? I looked around and couldn't find the IR specs for 2-Tolunitrile anywhere. thanks

[HB]

The IR of 2-Tolunitrile should contain CH aliphatic band at 2800-2900 cm-1 which will not be present in benzonitrile.

you can also download the IR charts of both compounds and compare the fingerprint region with that you have. you can use the link below to search for the charts
http://sdbs.riodb.aist.go.jp/sdbs/cgi-bin/cre_index.cgi?lang=eng