Question

Diethyl ether has the following structure Which groups of protons are equivalent to each other? How many signals (individual resonances, not counting splitting) are expected in the 1H NMR spectrum?

Answer 1

Concepts and reason

A compound is given in which the number of equivalent protons needs to be identified along with the number of signals given by the compound in $^1{\rm{H - NMR}}$ . Equivalent protons are present in chemically same environment, thus, identify the protons which are having similar chemical environment.

Similarly, the number of signals obtained in NMR is also depend on the different type of protons present in the compound.

Fundamentals

NMR stands for nuclear magnetic resonance which is a useful spectroscopic technique for determining the type of protons and the number of protons in the compounds.

A set of protons which are present in same chemical environment, that is, present between the same group of atoms are said to be chemically equivalent protons. All chemically equivalent proton generates 1 signal or 1 peak in $^1{\rm{H - NMR}}$ .

A set of protons which are present in different chemical environment, that is, present between the different group of atoms are said to be chemically non-equivalent protons. All chemically non-equivalent proton generates distinct signal in $^1{\rm{H - NMR}}$ .

Draw the given structure of the compound and identify the number of carbons that are present in different environment. Thus, identify the protons that are equivalent as shown below:

The protons that are shown with the same color are equivalent to each other.

Identify the distinct protons and then calculate the number of signals in $^1{\rm{H - NMR}}$ of the given compound as follows:

As the two distinct sets of protons are present, therefore, the number of signals obtained will be 2.

Ans:

Hence, the group of protons that are equivalent are shown as follows:

Hence, the number of signals obtained in $^1{\rm{H - NMR}}$ is shown below: