Chapter 15, Problem 81CP

(a)

Interpretation Introduction

Interpretation:

The protons that give rise to the given signals have to be drawn and the decision has to be justified using resonance structures.

Concept introduction:

NMR spectroscopy:

It is the study of the interaction between electromagnetic radiation and the nuclei of atoms and the variety of nuclei studied includes ${}^{\text{1}}\text{H,}{}^{\text{13}}\text{C,}{}^{\text{15}}\text{N,}{}^{\text{19}}\text{F}\text{and}{}^{\text{31}}\text{P}$

${}^{1}HNMR$: A technique gives information to predict the Carbon and Hydrogen connectivity in the organic compounds.

Resonance: An electron displacement effect for stabilizing a molecule through delocalization of bonding electrons in the pi orbital.

Delocalized electrons stabilize a compound. The extra stability gains from having delocalized electrons are called resonance stabilization or resonance energy.

(b)

Interpretation Introduction

Interpretation:

It has to be identified whether the IR signal corresponding to the $\text{C3-C4}$ $\pi$ bond is stronger in compound 1 or in compound 2 and the reason has to be explained.

Concept introduction:

NMR spectroscopy:

It is the study of the interaction between electromagnetic radiation and the nuclei of atoms and the variety of nuclei studied includes ${}^{\text{1}}\text{H,}{}^{\text{13}}\text{C,}{}^{\text{15}}\text{N,}{}^{\text{19}}\text{F}\text{and}{}^{\text{31}}\text{P}$

${}^{\text{1}}\text{H NMR}$: A technique gives information to predict the Carbon and Hydrogen connectivity in the organic compounds.

Resonance is an electron displacement effect for stabilizing a molecule through delocalization of bonding electrons in the pi orbital.

Delocalized electrons stabilize a compound. The extra stability gains from having delocalized electrons are called resonance stabilization or resonance energy.