Chapter 16, Problem 42PP

 (a)

Interpretation Introduction

Interpretation: For a given molecule the number of signals expected in ${}^{\text{1}}\text{H}\text{NMR}$ and ${}^{\text{13}}\text{C}\text{NMR}$ spectrum to be identified.

Concept Introduction:

Proton signals: In ${}^{\text{1}}\text{H}\text{NMR}$ spectrum, the signal gives rise due to the different kind of protons predicted by performing symmetry operation.

Carbon signals: In ${}^{\text{13}}\text{C}\text{NMR}$ spectrum, the signal gives rise due to the different kind of carbon atoms predicted by performing symmetry operation.

Factors affect the chemical shift values: The electronegative atoms which present nearer to the subjected protons withdraw electron density around the protons inductively makes the protons deshielded and shift the chemical shift value towards downfield.

(b)

Interpretation Introduction

Interpretation: For a given molecule the number of signals expected in ${}^{\text{1}}\text{H}\text{NMR}$ and ${}^{\text{13}}\text{C}\text{NMR}$ spectrum to be identified.

Concept Introduction:

Proton signals: In ${}^{\text{1}}\text{H}\text{NMR}$ spectrum, the signal gives rise due to the different kind of protons predicted by performing symmetry operation.

Carbon signals: In ${}^{\text{13}}\text{C}\text{NMR}$ spectrum, the signal gives rise due to the different kind of carbon atoms predicted by performing symmetry operation.

Factors affect the chemical shift values: The electronegative atoms which present nearer to the subjected protons withdraw electron density around the protons inductively makes the protons deshielded and shift the chemical shift value towards downfield.

(c)

Interpretation Introduction

Interpretation: For a given molecule the number of signals expected in ${}^{\text{1}}\text{H}\text{NMR}$ and ${}^{\text{13}}\text{C}\text{NMR}$ spectrum to be identified.

Concept Introduction:

Proton signals: In ${}^{\text{1}}\text{H}\text{NMR}$ spectrum, the signal gives rise due to the different kind of protons predicted by performing symmetry operation.

Carbon signals: In ${}^{\text{13}}\text{C}\text{NMR}$ spectrum, the signal gives rise due to the different kind of carbon atoms predicted by performing symmetry operation.

Factors affect the chemical shift values: The electronegative atoms which present nearer to the subjected protons withdraw electron density around the protons inductively makes the protons deshielded and shift the chemical shift value towards downfield.

(d)

Interpretation Introduction

Interpretation: For a given molecule the number of signals expected in ${}^{\text{1}}\text{H}\text{NMR}$ and ${}^{\text{13}}\text{C}\text{NMR}$ spectrum to be identified.

Concept Introduction:

Proton signals: In ${}^{\text{1}}\text{H}\text{NMR}$ spectrum, the signal gives rise due to the different kind of protons predicted by performing symmetry operation.

Carbon signals: In ${}^{\text{13}}\text{C}\text{NMR}$ spectrum, the signal gives rise due to the different kind of carbon atoms predicted by performing symmetry operation.

Factors affect the chemical shift values: The electronegative atoms which present nearer to the subjected protons withdraw electron density around the protons inductively makes the protons deshielded and shift the chemical shift value towards downfield.