Nuclear Magnetic Resonance (NMR) spectroscopy is a powerful analytical technique employed by chemists to elucidate the structures of molecules. This method involves applying a magnetic field to a sample and subsequently measuring the energy absorbed by the nuclei when they are exposed to radiofrequency radiation. The resulting spectrum features peaks that correspond to different resonances, or energy levels, of the nuclei.

In the context of NMR, the types of peaks observed in the spectrum provide critical insights into the molecular structure:

• Singlet Peaks: These are the simplest peaks observed in an NMR spectrum. A singlet peak signifies a single resonance, indicating that the nucleus is in one specific energy state. This typically implies that the atom in question is either not adjacent to any other atoms of the same type or is adjacent to atoms of the same type that are all in an identical chemical environment.

• Doublet Peaks: Doublets are slightly more intricate, representing two closely spaced resonances. This pattern usually suggests that the atom in focus is adjacent to one other atom of the same type but in a different chemical environment. In a doublet, the two peaks are of equal intensity and are separated by a specific distance known as the coupling constant, denoted as $J$.

• Triplet Peaks: Triplets are even more complex and signify three closely spaced resonances. This pattern typically indicates that the atom in question is adjacent to two other atoms of the same type, each in different chemical environments. In a triplet, the peaks are not of equal intensity; rather, the middle peak is twice as intense as the outer peaks, forming a characteristic intensity ratio of $1:2:1$.

In summary, the number and arrangement of peaks in an NMR spectrum yield valuable information regarding a molecule’s structure. Singlet peaks indicate a single resonance, doublet peaks indicate two resonances, and triplet peaks indicate three resonances. By analyzing these peaks, chemists can ascertain the arrangement of atoms within a molecule and gain insights into its chemical behavior.