(•) For the following molecules, give the integration you would expect for the signal associated with the hydrogens at the labeled carbons. [Pay attention to the symmetry, or lack of symmetry, in the molecules.] (e)

Verified step by step guidance

1. Identify the labeled carbon atoms in the molecule and determine the number of hydrogen atoms attached to each labeled carbon.
2. Consider the symmetry of the molecule. Symmetrical molecules may have equivalent hydrogens that contribute to the same NMR signal.
3. For each labeled carbon, count the number of hydrogens directly attached to it. This count will determine the integration value for the NMR signal associated with those hydrogens.
4. If the molecule has symmetrical parts, identify equivalent hydrogens that will contribute to the same signal and sum their contributions for the integration value.
5. Compile the integration values for each set of equivalent hydrogens, ensuring that the total integration reflects the number of hydrogens contributing to each signal.

Key Concepts

Integration in NMR Spectroscopy

Integration in NMR (Nuclear Magnetic Resonance) spectroscopy refers to the area under the peaks in an NMR spectrum, which is proportional to the number of protons contributing to that signal. This allows chemists to determine the relative number of hydrogen atoms in different environments within a molecule. Understanding integration is crucial for interpreting the signals associated with specific hydrogens in a compound.

Chemical Environment of Hydrogens

The chemical environment of hydrogens in a molecule affects their resonance frequency in NMR spectroscopy. Hydrogens attached to different types of carbon atoms or in different functional groups will resonate at different chemical shifts. Recognizing how the structure influences the chemical environment helps predict the expected integration values for the signals associated with specific hydrogens.

Symmetry in Molecules

Symmetry in molecules can significantly influence the NMR signals observed. Symmetrical molecules may have equivalent hydrogens that produce fewer distinct signals, while asymmetrical molecules typically show more complex patterns. Understanding the symmetry of a molecule is essential for accurately predicting the integration of signals, as it determines how many unique environments exist for the hydrogens.