Chapter 13, Problem 13.13P

Interpretation Introduction

(a)

Interpretation:

The $\text{NMR}$ spectrum of $1,1-\text{dichloro ethane}$ including splitting is to be predicted.

Concept introduction:

Nuclear magnetic resonance is a type of spectroscopy in which number of different kind of protons present in different environment can be detected. The $\text{NMR}$ spectra of any molecule can easily interpreted if structure of a molecule is known. In the $\text{NMR}$ spectra, sometimes one absorption peak is splitted into two or more peaks. This is due to the spin of neighboring proton which affects the total magnetic field experienced by an observed proton.

Answer to Problem 13.13P

The $\text{NMR}$ spectrum of $1,1-\text{dichloro ethane}$ including splitting gives two signals. One is doublet and other one is quartet. In structure ${\text{H}}_{\text{3}}\text{C}-{\text{CHCl}}_{\text{2}}$ hydrogen attached to $\text{2}$ chlorine atoms has more chemical shift as comapred to the methyl hydrogens.

Explanation of Solution

The structure of $1,1-\text{dichloro ethane}$ is shown below in Figure 1.

Figure 1

In the given structure of $1,1-\text{dichloro ethane}$ molecule, there are two types of hydrogens. The hydrogen which are directly attached to the chlorine atoms are deshieled. Due to presence of an electron withdrawing group, chemical shift for protons $\left(b\right)$ is more than the chemical shift of proton $\left(a\right)$. Splitting of the signal is determined by $\left(\text{n}+\text{1}\right)$ rule. Where $\text{n}$ is the number of hydrogen atoms attached to the observable proton. Therefore, signal of proton $\left(b\right)$ is splitted into $\left(3+\text{1}\right)=4$ lines. The protons of methyl group is shielded due to which chemical shift of proton $\left(a\right)$ is less. The signal of proton $\left(a\right)$ is spliited according to $\left(\text{n}+\text{1}\right)$ rule. Therefore, a doublet for proton $\left(a\right)$ and a quartet for proton $\left(b\right)$ is observed in the $\text{NMR}$ spectrum of $1,1-\text{dichloro ethane}$.

Conclusion

The $\text{NMR}$ spectrum of $1,1-\text{dichloro ethane}$ gives two signals. One is quartet and other one is doublet. In structure ${\text{H}}_{\text{3}}\text{C}-{\text{CHCl}}_{\text{2}}$ hydrogen attached to $\text{2}$ chlorine atoms has more chemical shift as comapred to the methyl hydrogens.

Interpretation Introduction

(b)

Interpretation:

The $\text{NMR}$ spectrum of $1,1,2-\text{trichloro ethane}$ including splitting is to be predicted.

Concept introduction:

Nuclear magnetic resonance is a type of spectroscopy in which number of different kind of protons present in different environment can be detected. The $\text{NMR}$ spectra of any molecule can easily interpreted if structure of a molecule is known. In the $\text{NMR}$ spectra, sometimes one absorption peak is splitted into two or more peaks. This is due to the spin of neighboring proton which affects the total magnetic field experienced by an observed proton.

Answer to Problem 13.13P

The $\text{NMR}$ spectrum of $1,1,2-\text{trichloro ethane}$ including splitting gives two signals. One is doublet and other one is triplet. In structure ${\text{ClCH}}_2-{\text{CHCl}}_{\text{2}}$ hydrogen attached to $\text{2}$ chlorine atoms has more chemical shift as comapred to the methylene hydrogens.

Explanation of Solution

The structure of $1,1,2-\text{trichloro ethane}$ is shown below in Figure 2.

Figure 2

In the given structure of $1,1,2-\text{trichloro ethane}$ molecule, there are two types of hydrogens. The hydrogen $\left(b\right)$ which are directly attached to the more number of chlorine atoms are more deshieled than the protons $\left(a\right)$. Due to presence of an electron withdrawing group, chemical shift for protons $\left(b\right)$ is more than the chemical shift of proton $\left(a\right)$. Splitting of the signal is determined by $\left(\text{n}+\text{1}\right)$ rule. Where $\text{n}$ is the number of hydrogen atoms attached to the observable proton. Therefore, signal of proton $\left(b\right)$ is splitted into $\left(2+\text{1}\right)=3$ lines. The protons of methylene group is slightly deshielded due to which chemical shift of proton $\left(a\right)$ is less than the chemical shift of protons $\left(b\right)$. The signal of proton $\left(a\right)$ is spliited according to $\left(\text{n}+\text{1}\right)$ rule. Therefore, a doublet for proton $\left(a\right)$ and a triplet for proton $\left(b\right)$ is observed in the $\text{NMR}$ spectrum of $1,1,2-\text{trichloro ethane}$.

Conclusion

The $\text{NMR}$ spectrum of $1,1,2-\text{trichloro ethane}$ gives two signals. One is triplet and other one is doublet. In structure ${\text{ClCH}}_2-{\text{CHCl}}_{\text{2}}$ hydrogen attached to $\text{2}$ chlorine atoms has more chemical shift as comapred to the methylene hydrogens.

Interpretation Introduction

(c)

Interpretation:

The $\text{NMR}$ spectrum of $\text{2}-\text{iodo propane}$ including splitting is to be predicted.

Concept introduction:

Nuclear magnetic resonance is a type of spectroscopy in which number of different kind of protons present in different environment can be detected. The $\text{NMR}$ spectra of any molecule can easily interpreted if structure of a molecule is known. In the $\text{NMR}$ spectra, sometimes one absorption peak is splitted into two or more peaks. This is due to the spin of neighboring proton which affects the total magnetic field experienced by an observed proton.

Answer to Problem 13.13P

The $\text{NMR}$ spectrum of $\text{2}-\text{iodo propane}$ including splitting gives two signals. One is doublet and other one is septet. In the structure of $\text{2}-\text{iodo propane}$, hydrogen attached to iodide atom has more chemical shift as comapred to the six methyl hydrogens.

Explanation of Solution

The structure of $\text{2}-\text{iodo propane}$ is shown below in Figure 3.

Figure 3

In the given structure of $\text{2}-\text{iodo propane}$ molecule, there are two types of hydrogens. The hydrogen $\left(a\right)$ which are directly attached to the electronegative iodine atom are more deshieled than the protons $\left(b\right)$. Due to presence of an electron withdrawing group, chemical shift for protons $\left(a\right)$ is more than the chemical shift of proton $\left(b\right)$. Splitting of the signal is determined by $\left(\text{n}+\text{1}\right)$ rule. Where $\text{n}$ is the number of hydrogen atoms attached to the observable proton. Therefore, signal of proton $\left(b\right)$ is splitted into $\left(1+\text{1}\right)=2$ lines. The protons $\left(b\right)$ are shielded due to which chemical shift of proton $\left(b\right)$ is less than the chemical shift of protons $\left(a\right)$. The signal of proton $\left(a\right)$ is spliited according to $\left(\text{n}+\text{1}\right)$ rule. Therefore, a doublet for proton $\left(b\right)$ and a septet for proton $\left(a\right)$ is observed in the $\text{NMR}$ spectrum of $\text{2}-\text{iodo propane}$.

Conclusion

The $\text{NMR}$ spectrum of $\text{2}-\text{iodo propane}$ gives two signals. One is septet and other one is doublet. In $\text{2}-\text{iodo propane}$ hydrogen attached to iodine atom has more chemical shift as comapred to the six methyl protons.

Interpretation Introduction

(d)

Interpretation:

The $\text{NMR}$ spectrum of $\text{1, 3}-\text{dimethoxy propane}$ including splitting is to be predicted.

Concept introduction:

Nuclear magnetic resonance is a type of spectroscopy in which number of different kind of protons present in different environment can be detected. The $\text{NMR}$ spectra of any molecule can easily interpreted if structure of a molecule is known. In the $\text{NMR}$ spectra, sometimes one absorption peak is splitted into two or more peaks. This is due to the spin of neighboring proton which affects the total magnetic field experienced by an observed proton.

Answer to Problem 13.13P

The $\text{NMR}$ spectrum of $\text{1, 3}-\text{dimethoxy propane}$ including splitting gives three signals. One is singlet, one is triplet and one is quintet. In the structure of $\text{1, 3}-\text{dimethoxy propane}$, hydrogen attached directly to oxygen atom has more chemical shift as comapred to the two methylene hydrogens.

Explanation of Solution

The structure of $\text{1, 3}-\text{dimethoxy propane}$ is shown below in Figure 4.

Figure 4

In the given structure of $\text{1, 3}-\text{dimethoxy propane}$ molecule, there are three types of hydrogens. The hydrogen $\left(b\right)$ which are directly attached to the electronegative oxygen atom and carbon atom are more deshieled than the protons $\left(a\right)$. Due to presence of an electron withdrawing group, chemical shift for protons $\left(b\right)$ is more than the chemical shift of proton $\left(a\right)$. Chemical shift of the protons attached directly to carbon atoms have least chemical shift. Splitting of the signal is determined by $\left(\text{n}+\text{1}\right)$ rule. Where $\text{n}$ is the number of hydrogen atoms attached to the observable proton. Therefore, signal of proton $\left(b\right)$ is splitted into $\left(2+\text{1}\right)=3$ lines. The signal of proton $\left(a\right)$ is spliited according to $\left(\text{n}+\text{1}\right)$ rule to give a single peak. Signal of proton $\left(c\right)$ is splitted into $\left(2+2+1\right)=5$ Therefore, a singlet for proton $\left(a\right)$, a triplet for proton $\left(a\right)$ and a quintet for proton $\left(c\right)$ is observed in the $\text{NMR}$ spectrum of $\text{1, 3}-\text{dimethoxy propane}$.

Conclusion

The $\text{NMR}$ spectrum of $\text{1, 3}-\text{dimethoxy propane}$ gives three signals. A quintet, triplet and singlet is observed for $\text{1, 3}-\text{dimethoxy propane}$. The hydrogens attached to oxygen and carbon atom has more chemical shift than the protons attached directlt to only oxygen atoms. Chemical shift of methylene protons is the least.

Interpretation Introduction

(e)

Interpretation:

The $\text{NMR}$ spectrum of oxetane ring including splitting is to be predicted.

Concept introduction:

Nuclear magnetic resonance is a type of spectroscopy in which number of different kind of protons present in different environment can be detected. The $\text{NMR}$ spectra of any molecule can easily interpreted if structure of a molecule is known. In the $\text{NMR}$ spectra, sometimes one absorption peak is splitted into two or more peaks. This is due to the spin of neighboring proton which affects the total magnetic field experienced by an observed proton.

Answer to Problem 13.13P

The $\text{NMR}$ spectrum of oxetane ring including splitting gives two signals. One is triplet and other one is quintet. In oxetane ring, hydrogen attached to oxygen atom has more chemical shift as comapred to the two methylene hydrogens.

Explanation of Solution

The structure of oxetane ring is shown below in Figure 5.

Figure 5

In the given structure of oxetane ring, two types of hydrogens are present. The hydrogen $\left(a\right)$ which are directly attached to the electronegative oxygen atom are deshieled than the protons $\left(b\right)$. Due to presence of an electron withdrawing group, chemical shift for protons $\left(a\right)$ is more than the chemical shift of proton $\left(b\right)$. Splitting of the signal is determined by $\left(\text{n}+\text{1}\right)$ rule. Where $\text{n}$ is the number of hydrogen atoms attached to the observable proton. Therefore, signal of proton $\left(b\right)$ is splitted into $\left(2+2+\text{1}\right)=5$ lines. The protons $\left(b\right)$ are shielded due to which chemical shift of proton $\left(b\right)$ is less than the chemical shift of protons $\left(a\right)$. The signal of proton $\left(a\right)$ is spliited according to $\left(\text{n}+\text{1}\right)$ rule into $\left(2+\text{1}\right)=3$ lines. Therefore, a quintet for proton $\left(b\right)$ and a triplet for proton $\left(a\right)$ is observed in the $\text{NMR}$ spectrum of oxetane ring.

Conclusion

The $\text{NMR}$ spectrum of oxetane ring gives two signals. One is quintet and other one is triplet. In oxetane ring, hydrogen attached directly to oxygen atom has more chemical shift as comapred to the two methylene protons.

Interpretation Introduction

(f)

Interpretation:

The $\text{NMR}$ spectrum of $\text{1, 2}-\text{dichloro-2-methyl propane}$ including splitting is to be predicted.

Concept introduction:

Nuclear magnetic resonance is a type of spectroscopy in which number of different kind of protons present in different environment can be detected. The $\text{NMR}$ spectra of any molecule can easily interpreted if structure of a molecule is known. In the $\text{NMR}$ spectra, sometimes one absorption peak is splitted into two or more peaks. This is due to the spin of neighboring proton which affects the total magnetic field experienced by an observed proton.

Answer to Problem 13.13P

The $\text{NMR}$ spectrum of $\text{1, 2}-\text{dichloro-2-methyl propane}$ including splitting gives two signals. Both the signals are singlet. In $\text{1, 2}-\text{dichloro-2-methyl propane}$, hydrogen attached directly to chlorine atom has more chemical shift as comapred to the six methyl hydrogens

Explanation of Solution

The structure of $\text{1, 2}-\text{dichloro-2-methyl propane}$ is shown below in Figure 6.

Figure 6

In the given structure of $\text{1, 2}-\text{dichloro-2-methyl propane}$, two types of hydrogens are present. The hydrogen $\left(a\right)$ which are directly attached to the electronegative chlorine atom are deshieled than the protons $\left(b\right)$. Due to presence of an electron withdrawing group, chemical shift for protons $\left(a\right)$ is more than the chemical shift of proton $\left(b\right)$. Splitting of the signal is determined by $\left(\text{n}+\text{1}\right)$ rule. Where $\text{n}$ is the number of hydrogen atoms attached to the observable proton. Therefore, signal of proton $\left(b\right)$ is not splitted and gives only $\left(0+\text{1}\right)=1$ line. The protons $\left(b\right)$ are shielded due to which chemical shift of proton $\left(b\right)$ is less than the chemical shift of protons $\left(a\right)$. The signal of proton $\left(a\right)$ is splitted according to $\left(\text{n}+\text{1}\right)$ rule into $\left(0+\text{1}\right)=1$ line. Therefore, two singlets for proton $\left(a\right)$ and $\left(b\right)$ are observed for $\text{1, 2}-\text{dichloro-2-methyl propane}$.

Conclusion

The $\text{NMR}$ spectrum of $\text{1, 2}-\text{dichloro-2-methyl propane}$ including splitting contains two singlet signals in which hydrogens directl attached to chlorine atom has more chemical shift than the other hydrogen.