Chapter 16.7, Problem 17CC

(a)

Interpretation Introduction

Interpretation: The characteristic pattern of groups to be identified from the given spectra.

Concept Introduction:

Integration value: The integration value at the top of the ${}^{\text{1}}\text{H}\text{NMR}$ spectrum represents the number of protons giving rise to the signal.

Coupling constant:

1. 1. When a splitting of each signal occurs the distance between the individual peaks on the splitting pattern is termed as coupling constant and measured in hertz. Coupling constant depends on the kind of neighboring protons involved but not on the operating frequency of spectrometer.
2. 2. When the two kinds of protons (subjected protons and neighboring protons) are splitting to each other the coupling constant will be same for both signals.

• Ethyl group :

$\text{quartet}$ $\text{triplet}$

Exhibits quartet splitting pattern with integration value of two protons.

Exhibits triplet splitting pattern with integration value of three protons.

• Isopropyl group :

  $\text{doublet}$

   Exhibits septet splitting pattern with integration of one proton.

  Exhibits doublet splitting pattern with integration of six protons.

• Tert-butyl group:

$\text{singlet}$

Exhibits singlet splitting pattern with integration of six protons.

 (b)

Interpretation Introduction

Interpretation: The characteristic pattern of groups to be identified from the given spectra.

Concept Introduction:

Integration value: The integration value at the top of the ${}^{\text{1}}\text{H}\text{NMR}$ spectrum represents the number of protons giving rise to the signal.

Coupling constant:

1. 3. When a splitting of each signal occurs the distance between the individual peaks on the splitting pattern is termed as coupling constant and measured in hertz. Coupling constant depends on the kind of neighboring protons involved but not on the operating frequency of spectrometer.
2. 4. When the two kinds of protons (subjected protons and neighboring protons) are splitting to each other the coupling constant will be same for both signals.

• Ethyl group :

$\text{quartet}$ $\text{triplet}$

Exhibits quartet splitting pattern with integration value of two protons.

Exhibits triplet splitting pattern with integration value of three protons.

• Isopropyl group :

  $\text{doublet}$

   Exhibits septet splitting pattern with integration of one proton.

  Exhibits doublet splitting pattern with integration of six protons.

• Tert-butyl group:

$\text{singlet}$

Exhibits singlet splitting pattern with integration of six protons.

(c)

Interpretation Introduction

Interpretation: The characteristic pattern of groups to be identified from the given spectra.

Concept Introduction:

Integration value: The integration value at the top of the ${}^{\text{1}}\text{H}\text{NMR}$ spectrum represents the number of protons giving rise to the signal.

Coupling constant:

1. 5. When a splitting of each signal occurs the distance between the individual peaks on the splitting pattern is termed as coupling constant and measured in hertz. Coupling constant depends on the kind of neighboring protons involved but not on the operating frequency of spectrometer.
2. 6. When the two kinds of protons (subjected protons and neighboring protons) are splitting to each other the coupling constant will be same for both signals.

• Ethyl group :

$\text{quartet}$ $\text{triplet}$

Exhibits quartet splitting pattern with integration value of two protons.

Exhibits triplet splitting pattern with integration value of three protons.

• Isopropyl group :

  $\text{doublet}$

   Exhibits septet splitting pattern with integration of one proton.

  Exhibits doublet splitting pattern with integration of six protons.

• Tert-butyl group:

$\text{singlet}$

Exhibits singlet splitting pattern with integration of six protons.

(d)

Interpretation Introduction

Interpretation: The characteristic pattern of groups to be identified from the given spectra.

Concept Introduction:

Integration value: The integration value at the top of the ${}^{\text{1}}\text{H}\text{NMR}$ spectrum represents the number of protons giving rise to the signal.

Coupling constant:

1. 7. When a splitting of each signal occurs the distance between the individual peaks on the splitting pattern is termed as coupling constant and measured in hertz. Coupling constant depends on the kind of neighboring protons involved but not on the operating frequency of spectrometer.
2. 8. When the two kinds of protons (subjected protons and neighboring protons) are splitting to each other the coupling constant will be same for both signals.

• Ethyl group :

$\text{quartet}$ $\text{triplet}$

Exhibits quartet splitting pattern with integration value of two protons.

Exhibits triplet splitting pattern with integration value of three protons.

• Isopropyl group :

  $\text{doublet}$

   Exhibits septet splitting pattern with integration of one proton.

  Exhibits doublet splitting pattern with integration of six protons.

• Tert-butyl group:

$\text{singlet}$

Exhibits singlet splitting pattern with integration of six protons.