15. Analytical Techniques:IR, NMR, Mass Spect

Which of the following characteristic absorption bands would you expect to observe in the infrared (IR) spectrum of benzil ($C_{14}{H}_{10}{O}_2$)?

Which of the following characteristic absorption bands would you expect to observe in the IR spectrum of triphenylmethanol?

Which of the following characteristic absorption bands would you expect to observe in the IR spectrum of salicylamide?

Which of the following molecular vibrations is expected to be infrared active?

Which of the following molecular vibrations is expected to be infrared active?

Consider the IR spectrum of an unknown compound. Which absorption is most indicative of the presence of a carbonyl group ($>C=O$) in the molecule?

Which region in the IR spectrum could be used to distinguish between butanoic acid and 2-butanone?

Which of the following peaks would you expect to be labeled in the infrared (IR) spectrum of acetaminophen?

Which of the following characteristic absorption bands would you expect to observe in the IR spectrum of 2-naphthol?

Which of the bonds shown in red are expected to have IR-active stretching frequencies?

Which of the following characteristic absorption bands would you expect to observe in the IR spectrum of benzyl acetate?

Which of the following characteristic absorption bands would you expect to observe in the IR spectrum of eugenol?

Which occurs at a larger wavenumber:

a. the C–O stretch of phenol or the C–O stretch of cyclohexanol?

b. the C=O stretch of a ketone or the C=O stretch of an amide?

c. the C–N stretch of cyclohexylamine or the C–N stretch of aniline?

Justify the carbonyl stretching frequencies indicated for 3-chlorobenzaldehyde and 3-fluorobenzaldehyde.