Chapter 13, Problem 13.37AP

Interpretation Introduction

(a)

Interpretation:

An explanation as to how the compounds cyclohexane and $trans\text{-2-hexene}$ are distinguished using NMR spectra is to be stated.

Concept introduction:

Many nuclei and electrons have spin. Due to this spin magnetic moment arises. The energy of this magnetic moment depends on the orientation of the applied magnetic field. In NMR spectroscopy, every nucleus has a spin. There is an angular momentum related to the spin. The difference between its resonance frequency and that of the reference standard is known as the chemical shift of a nucleus. Tetramethylsilane (TMS) is taken as reference.

Answer to Problem 13.37AP

The cyclohexane gives only a single peak for all the hydrogens in the compounds while the $trans\text{-2-hexene}$ gives six signals in the NMR spectra. Both compounds are distinguished on the basis of the number of NMR signals.

Explanation of Solution

The compounds cyclohexane and $trans\text{-2-hexene}$ can be distinguished on the basis of NMR signals to be observed in the compound. Both of the compounds contain the same number of hydrogens. The NMR spectra of cyclohexane gives only one signal as all the hydrogens are equivalent in the compound. The $trans\text{-2-hexene}$ gives six signals due to the presence of six sets of protons in the compound.

The structure of $trans\text{-2-hexene}$ is given below along with six set of protons labeled alphabetically.

Figure 1

The structure of the cyclohexane along with its all equivalent protons peak data is shown below.

Figure 2

Conclusion

The cyclohexane gives only a single peak for all the hydrogens in the compounds while the $trans\text{-2-hexene}$ gives six signals in the NMR spectra.

Interpretation Introduction

(b)

Interpretation:

An explanation as to how the compounds $trans\text{-3-hexene}$ and $\text{1-hexene}$ are distinguished using NMR spectra is to be stated.

Concept introduction:

Many nuclei and electrons have spin. Due to this spin magnetic moment arises. The energy of this magnetic moment depends on the orientation of the applied magnetic field. In NMR spectroscopy, every nucleus has a spin. There is an angular momentum related to the spin. The difference between its resonance frequency and that of the reference standard is known as the chemical shift of a nucleus. Tetramethylsilane (TMS) is taken as reference.

Answer to Problem 13.37AP

The $trans\text{-3-hexene}$ gives only three signals for all the hydrogens in the compounds while the $\text{1-hexene}$ gives seven signals in the NMR spectra. Both compounds are distinguished on the basis of the number of NMR signals.

Explanation of Solution

The compounds $trans\text{-3-hexene}$ and $\text{1-hexene}$ can be distinguished on the basis of NMR signals to be observed in the compound. Both of the compounds contain the same number of hydrogens. The NMR spectra of $trans\text{-3-hexene}$ gives only three signals due to the presence of three sets of protons because of being symmetrical compound. The $\text{1-hexene}$ gives seven signals due to the presence of seven sets of protons in the compound.

The structure of $trans\text{-3-hexene}$ is given below along with three sets of protons labeled alphabetically.

Figure 3

The structure of the $\text{1-hexene}$ is given below along with seven sets of protons labeled alphabetically.

Figure 4

Conclusion

The $trans\text{-3-hexene}$ gives only three signals for all the hydrogens in the compounds while the $\text{1-hexene}$ gives seven signals in the NMR spectra.

Interpretation Introduction

(c)

Interpretation:

An explanation as to how the compounds $\text{1, 1-dichlorohexane}$, $\text{1, 6-dichlorohexane}$, and $\text{1, 2-dichlorohexane}$ are distinguished using NMR spectra is to be stated.

Concept introduction:

Many nuclei and electrons have spin. Due to this spin magnetic moment arises. The energy of this magnetic moment depends on the orientation of the applied magnetic field. In NMR spectroscopy, every nucleus has a spin. There is an angular momentum related to the spin. The difference between its resonance frequency and that of the reference standard is known as the chemical shift of a nucleus. Tetramethylsilane (TMS) is taken as reference.

Answer to Problem 13.37AP

The $\text{1, 6-dichlorohexane}$ gives only three signals for all the hydrogens in the compounds while the $\text{1, 2-dichlorohexane}$ and $\text{1, 1-dichlorohexane}$ gives six signals in the NMR spectra. These two compounds $\text{1, 2-dichlorohexane}$ and $\text{1, 1-dichlorohexane}$ having same number of signals are distinguished from each other on the basic of peaks at high chemical shift value. All the compounds are distinguished on the basis of the number of signals and chemical shift value of signals.

Explanation of Solution

The compounds $\text{1, 1-dichlorohexane}$, $\text{1, 6-dichlorohexane}$, and $\text{1, 2-dichlorohexane}$ can be distinguished on the basis of NMR signals to be observed in the compound. All three compounds contain the same number of hydrogens. The NMR spectra of $\text{1, 6-dichlorohexane}$ gives only three signals due to the presence of three sets of protons because of being symmetrical compound. The $\text{1, 1-dichlorohexane}$ gives the six signals due to the presence of six sets of protons in the compound. The $\text{1, 2-dichlorohexane}$ gives the six signals due to the presence of six sets of protons in the compound.

The two compounds $\text{1, 1-dichlorohexane}$ and $\text{1, 2-dichlorohexane}$ are differentiated from each other from the high chemical shift signals in the NMR spectrum. In the compound, $\text{1, 1-dichlorohexane}$ there is one signal at high chemical value at $5.0\text{ppm}$. In the compound, $\text{1, 2-dichlorohexane}$ there are two signals at high chemical shift value for the compound. One at $3.8\text{ppm}$ and other at $3.0\text{ppm}$.

The structure of $\text{1, 6-dichlorohexane}$ is given below along with three sets of protons labeled alphabetically.

Figure 5

The structure of the $\text{1, 1-dichlorohexane}$ is given below along with six sets of protons labeled alphabetically.

There is one signal at high chemical value at $5.0\text{ppm}$ in the compound.

Figure 6

The structure of the $\text{1, 2-dichlorohexane}$ is given below along with six sets of protons labeled alphabetically.

There are two signals at high chemical shift value for the compound. One at $3.8\text{ppm}$ and other at $3.0\text{ppm}$.

Figure 7

Conclusion

The $\text{1, 6-dichlorohexane}$ gives only three signals for all the hydrogens in the compounds while the $\text{1, 2-dichlorohexane}$ and $\text{1, 1-dichlorohexane}$ gives six signals in the NMR spectra. These two compounds $\text{1, 2-dichlorohexane}$ and $\text{1, 1-dichlorohexane}$ having same number of signals are distinguished from each other on the basic of peaks at high chemical shift value.

Interpretation Introduction

(d)

Interpretation:

An explanation as to how the compounds $tert-$ butyl methyl ether and isopropyl methyl ether are distinguished using NMR spectra is to be stated.

Concept introduction:

Many nuclei and electrons have spin. Due to this spin magnetic moment arises. The energy of this magnetic moment depends on the orientation of the applied magnetic field. In NMR spectroscopy, every nucleus has a spin. There is an angular momentum related to the spin. The difference between its resonance frequency and that of the reference standard is known as the chemical shift of a nucleus. Tetramethylsilane (TMS) is taken as reference.

Answer to Problem 13.37AP

The $tert-$ butyl methyl ether gives only two signals for all the hydrogens in the compounds while the isopropyl methyl ether gives three signals in the NMR spectra. Both compounds are distinguished on the basis of the number of NMR signals.

Explanation of Solution

The compounds $tert-$ butyl methyl ether and isopropyl methyl ether can be distinguished on the basis of NMR signals to be observed in the compound. Both of the compounds contain a different number of hydrogens. The NMR spectra of $tert-$ butyl methyl ether give only two signals due to the presence of two sets of protons. The isopropyl methyl ether gives three signals due to the presence of three sets of protons in the compound.

The only signal that is different in both the compounds is for the single hydrogen of methane group attached directly to the oxygen. Also, the splitting of the protons methyl groups into doublet occurs for isopropyl group while in $tert-$ butyl group all methyl groups give singlet peak.

The structure of $tert-$ butyl methyl ether is given below along with two sets of protons labeled alphabetically.

Figure 8

The structure of the isopropyl methyl ether is given below along with three sets of protons labeled alphabetically.

Figure 9

Conclusion

The $tert-$ butyl methyl ether gives only two signals for all the hydrogens in the compounds while the isopropyl methyl ether gives three signals in the NMR spectra.

Interpretation Introduction

(e)

Interpretation:

An explanation as to how the compounds ${\text{Cl}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CH}}_{\text{2}}-{\text{CHF}}_{\text{2}}$ and ${\text{H}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CCl}}_{\text{2}}-{\text{CClF}}_{\text{2}}$ are distinguished using NMR spectra is to be stated.

Concept introduction:

Many nuclei and electrons have spin. Due to this spin magnetic moment arises. The energy of this magnetic moment depends on the orientation of the applied magnetic field. In NMR spectroscopy, every nucleus has a spin. There is an angular momentum related to the spin. The difference between its resonance frequency and that of the reference standard is known as the chemical shift of a nucleus. Tetramethylsilane (TMS) is taken as reference.

Answer to Problem 13.37AP

The ${\text{H}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CCl}}_{\text{2}}-{\text{CClF}}_{\text{2}}$ ether gives only two signals for all the hydrogens in the compounds while the ${\text{Cl}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CH}}_{\text{2}}-{\text{CHF}}_{\text{2}}$ gives three signals in the NMR spectra.

Both compounds are distinguished on the basis of the number of NMR signals.

Explanation of Solution

The compounds ${\text{Cl}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CH}}_{\text{2}}-{\text{CHF}}_{\text{2}}$ and ${\text{H}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CCl}}_{\text{2}}-{\text{CClF}}_{\text{2}}$ can be distinguished on the basis of NMR signals to be observed in the compound. Both of the compounds contain the same number of hydrogens. The NMR spectra of ${\text{H}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CCl}}_{\text{2}}-{\text{CClF}}_{\text{2}}$ give only two signals due to the presence of two sets of protons. The ${\text{Cl}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CH}}_{\text{2}}-{\text{CHF}}_{\text{2}}$ gives the three signals due to the presence of three sets of protons in the compound.

The structure of ${\text{H}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CCl}}_{\text{2}}-{\text{CClF}}_{\text{2}}$ is given below along with two sets of protons labeled alphabetically.

Figure 10

The structure of the ${\text{Cl}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CH}}_{\text{2}}-{\text{CHF}}_{\text{2}}$ is given below along with three sets of protons labeled alphabetically.

Figure 11

Conclusion

The ${\text{H}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CCl}}_{\text{2}}-{\text{CClF}}_{\text{2}}$ ether gives only two signals for all the hydrogens in the compounds while the ${\text{Cl}}_{\text{3}}\text{C}-{\text{CH}}_{\text{2}}-{\text{CH}}_{\text{2}}-{\text{CHF}}_{\text{2}}$ gives three signals in the NMR spectra.