Question
13C NMR.
Draw the structure of methyl m-nitrobenzoate
Determine the # of unique Carbons with approximate chemical shift (I = 0-50, II = 50-100, III = 100-150, IV >150 ppm) and expected multiplicity (splitting pattern)
Draw the structure of methyl m-nitrobenzoate
Determine the # of unique Carbons with approximate chemical shift (I = 0-50, II = 50-100, III = 100-150, IV >150 ppm) and expected multiplicity (splitting pattern)
Answers
GPT 3.5
To determine the number of unique carbons and their expected chemical shifts and multiplicities in the 13C NMR spectrum of methyl m-nitrobenzoate, we first need to draw its structure.
The structure of methyl m-nitrobenzoate is as follows:
CH3-C6H4-NO2
Now, let's analyze the carbon atoms in this molecule:
1. The methyl (CH3) group attached to the benzene ring will show a peak in region I (0-50 ppm) with a singlet pattern due to the presence of 3 equivalent carbons.
2. The carbon atoms in the benzene ring will also appear in region I (0-50 ppm) with a peak for each carbon. The carbon atoms in the benzene ring will show a peak in region I (0-50 ppm) with a peak for each carbon. These are typically observed as a single peak in the NMR spectrum due to the high symmetry of the benzene ring.
3. The nitro group (NO2) will show a peak in region III (>100 ppm) due to the deshielding effect caused by the electronegative nitrogen and oxygen atoms. The nitro carbon is expected to be observed as a singlet due to its isolation from other carbon atoms.
In summary, the 13C NMR spectrum of methyl m-nitrobenzoate is expected to show:
- 3 unique carbon signals
- Chemical shift ranges:
I (0-50 ppm) - 4 carbons (3 from benzene ring, 1 from methyl group)
III (>100 ppm) - 1 carbon (nitro group)
- Multiplicity:
I (0-50 ppm) - Singlet
III (>100 ppm) - Singlet
The structure of methyl m-nitrobenzoate is as follows:
CH3-C6H4-NO2
Now, let's analyze the carbon atoms in this molecule:
1. The methyl (CH3) group attached to the benzene ring will show a peak in region I (0-50 ppm) with a singlet pattern due to the presence of 3 equivalent carbons.
2. The carbon atoms in the benzene ring will also appear in region I (0-50 ppm) with a peak for each carbon. The carbon atoms in the benzene ring will show a peak in region I (0-50 ppm) with a peak for each carbon. These are typically observed as a single peak in the NMR spectrum due to the high symmetry of the benzene ring.
3. The nitro group (NO2) will show a peak in region III (>100 ppm) due to the deshielding effect caused by the electronegative nitrogen and oxygen atoms. The nitro carbon is expected to be observed as a singlet due to its isolation from other carbon atoms.
In summary, the 13C NMR spectrum of methyl m-nitrobenzoate is expected to show:
- 3 unique carbon signals
- Chemical shift ranges:
I (0-50 ppm) - 4 carbons (3 from benzene ring, 1 from methyl group)
III (>100 ppm) - 1 carbon (nitro group)
- Multiplicity:
I (0-50 ppm) - Singlet
III (>100 ppm) - Singlet