Question

Indicate how many 1H NMR signals (individual resonances, not counting splitting) are expected for the compound below.

Answer 1

Concepts and reason

The concept related in solving the problem is NMR (Nuclear Magnetic Resonance) spectroscopy.

NMR is basically a technique of spectroscopy that is used for the determination of the unique structure of a compound.

Fundamentals

There are various types of spectrometers like N-NMR (Nitrogen NMR), C-NMR (Carbon NMR), but here, the main focus is on H-NMR (Hydrogen NMR). It helps in identifying the hydrogen-carbon framework in a compound (inorganic).

With the help of this technique one can determine the whole structure of any molecule and from that structure one can identify the number of signals that are produced by the hydrogen atoms. In a group of protons (chemically equivalent), signals are produced. Therefore, by looking at the hydrogen atoms, signals can be identified.

There are certain protons that are chemically equivalent and are present in the same environment. They are therefore, identical in every manner like in experiencing the same magnetic force and would also form signals that are overlapping on the spectrum.

Thus, from a given molecule one can identify the number of equivalent protons and so, the number of signals can be identified. Certain molecules possess different signals, which are identified on the basis of the properties of the hydrogen atoms.

The structure of the molecule is as follows:

There aresignals that are produced by the molecule. One signal is produced by the hydrogen atom ofmolecule, the second signal is produced by the hydrogen atom ofmolecule and the third signal is produced from themolecule. Therefore, there are signals all together that are produced by the molecule as shown diagrammatically.

Ans:

There are 1H-NMR signals that are expected to be produced by the indicated molecules as follow.