These are my peaks for isopentyl acetate IR spectrum, what functional groups are they: ex.) C-H, C-H2, C-H3, C=0, C-O, O-H etc 2958 2872 1739 1465 1387 1366 1227 1171 1055 1029
The Correct Answer and Explanation is:
The IR spectrum of isopentyl acetate has the following characteristic peaks:
- 2958 cm⁻¹ and 2872 cm⁻¹ – These peaks are associated with C-H stretching vibrations in alkyl groups. Specifically, the peak at 2958 cm⁻¹ is due to the asymmetric stretching of C-H bonds in methyl (CH₃) and methylene (CH₂) groups, while 2872 cm⁻¹ corresponds to symmetric C-H stretching of the methylene groups.
- 1739 cm⁻¹ – This is a C=O stretch (carbonyl stretch) typical for esters like isopentyl acetate. This sharp peak is characteristic of the ester carbonyl group, which is formed when an alcohol reacts with an acid.
- 1465 cm⁻¹ and 1387 cm⁻¹ – These peaks are related to C-H bending vibrations in the methyl (CH₃) groups. The bending vibrations are typically observed in the range of 1370–1450 cm⁻¹.
- 1366 cm⁻¹ – This is another C-H bending peak, likely from the methyl groups (CH₃) in the molecule.
- 1227 cm⁻¹ and 1171 cm⁻¹ – These peaks correspond to C-O stretching vibrations, which are characteristic of ester linkages (C-O) in isopentyl acetate.
- 1055 cm⁻¹ and 1029 cm⁻¹ – These are likely associated with the C-O stretching vibrations in the ester group, which occur at slightly lower wavenumbers.
Summary of Functional Groups:
- C-H (from alkyl groups, observed in the regions 2958, 2872, 1465, 1387, 1366 cm⁻¹)
- C=O (ester carbonyl stretch at 1739 cm⁻¹)
- C-O (ester C-O stretch at 1227, 1171, 1055, 1029 cm⁻¹)
These functional groups are typical of isopentyl acetate, an ester formed from acetic acid and isopentyl alcohol. The ester functional group is the most prominent feature in the IR spectrum.
