The given passage is difficult to understand due to its formatting and incomplete sentences. However, I will try to provide a clear and concise explanation based on the information provided.
It seems that the passage is discussing the proton frequencies of different groups in a molecule. The passage mentions the "a," "b," and "c" protons and the nitro group.
Based on the given information, we can understand the following:
1. The "a" protons are at a specific frequency because the nitro group only withdraws electrons inductively from the carbons to which they are attached. This suggests that the nitro group has an electron-withdrawing effect on the "a" protons, which affects their frequency.
2. The "b" and "c" protons are at a different frequency compared to the "a" protons. This is because the nitro group withdraws electrons both inductively and by some other means from the carbons to which they are attached. The exact method of electron withdrawal is not specified in the given passage.
3. The "c" protons are at a specific frequency because the nitro group withdraws electrons inductively more from the carbons to which the "c" protons are attached. This is likely because those carbons are closest to the nitro group, resulting in a stronger electron-withdrawing effect.
In summary, the passage suggests that the nitro group in the molecule has an influence on the proton frequencies of the different groups ("a," "b," and "c"). The exact mechanism of electron withdrawal and its effect on the frequencies is not explicitly stated.