To sketch the 1H NMR spectrum of ethyl acetate, we need to consider the different types of hydrogen atoms present in the molecule. Ethyl acetate has the following structure:
In ethyl acetate, we can identify three distinct sets of protons:
- CH3 (Methyl group): The protons in the methyl group attached to the carbonyl (–CO–) contribute around 2.1 – 2.3 ppm. This signal is typically found downfield due to the electron-withdrawing effect of the carbonyl group.
- CH2 (Methylene group): The methylene protons (–OCH2–) are found at around 4.1 – 4.5 ppm, which is also downfield because of the influence of the electronegative oxygen atom.
- CH3 (Methyl group) on the ethyl chain: The terminal methyl group (–CH3) that is opposite the carbonyl appears at approximately 1.0 – 1.3 ppm and is more shielded, leading to its upfield position.
Based on these observations, a simple representation of the 1H NMR spectrum for ethyl acetate could include:
- A peak around 2.1 – 2.3 ppm for the methyl protons attached to the carbonyl.
- A peak around 4.1 – 4.5 ppm for the methylene protons adjacent to the oxygen.
- A peak around 1.0 – 1.3 ppm for the terminal methyl protons of the ethyl group.
In summary, the 1H NMR spectrum of ethyl acetate consists of distinct peaks corresponding to each set of protons, with characteristic chemical shifts influenced by nearby functional groups. Remember that these values are approximate and may vary slightly depending on the solvent and concentration used.