Question

Can someone please help me interpret the IR spectrum of isoamyl alcohol? Thank you.

Transmittance 3500 ini dicohol 3305.41 3000 2955 20 2928.96 2870.83 2500 Wavenumbers (cm-1) 2000 1701.33 1685 24 1500 1654.58 1647.99 s o 1466.23 1384.65 1366.83 17 18.65 163727 1540 1169.36 1212.18 1124.24 1000 1056.64 1009.85 966.39 835.59 DOS

Answer 1

The name of the structure which is corresponding to the given IR spectra is already given above. That is, isoamyl alcohol. Its IUPAC name is 3-methylbutan-1-ol. Isoamyl alcohol has a primary alcohol group and has a 4 carbon parent chain. Structure of this compound is as follows

  

HẠC CHỊ Isoamyl alcohol (3-methylbutan-1-ol)

Now we will analyse the given IR spectra:

• Since it has a primary alcohol O-H group, It gives a broad and strong peak at 3305 cm-1.
• One more important signal appears at 2955 cm-1 which represents the presence of C-H sp3 stretch of -CH₂- and -CH₃ groups.
• C-O-H bending vibration is coupled with H-C-H bending vibrations. It gives some weak peak around 1466 cm-1 region.
• -CH3 bending peak observe around 1366 cm-1 region.
• A strong single signal of C-O stretching vibration observed at 1056 cm-1 which confirms the presence of the primary alcohol in the compound.

Therefore, all the above details support the given IR spectra with the compound Isoamyl alcohol