Chapter 14, Problem 37P

Interpretation Introduction

Interpretation:

The structure of compound Y is to be proposed on the basis of $\text{H}\text{NMR}$ and IR.

Concept introduction:

Nuclear Magnetic Resonance (NMR) is one of the most capable analytical techniques used for determining the functional groups and how the atoms are structured and arranged in a molecule.

Few elements, such as ${}^{13}{\text{C and }}^1\text{H}$, have nuclei behaving as magnets about an axis. These elements are placed in magnetic field irradiated with electromagnetic energy of specific frequency and the nuclei tend to absorb energy via magnetic resonance. There is this graph that shows energy absorption frequencies and intensities of a sample kept in the magnetic field called nuclear magnetic resonance (NMR).

In $\text{NMR}$

spectroscopy, the proton nuclear magnetic resonance ${(}^{\text{1}}\text{H}\text{NMR)}$ is used to find out the structure of molecules with the help of ${}^{\text{1}}\text{H}$

atom within the molecules.

Induced magnetic field consists of electricity generated from movement in a magnetic field.

Infrared spectroscopy is a simple, instrumental technique, which helps to determine the presence of various functional groups.

It depends on the interactions of atoms or molecules with the electromagnetic radiation.

Infrared spectroscopy is most commonly used in the identification of the structure of the compound.

Infrared spectroscopy is the examination of the infrared light interacting with a molecule. The examination can be done in three ways, that is, by measuring absorption, emission, and reflection, and it can also measure the vibration of atoms.

${}^{13}\text{C}$

NMR is only used in the observation of isotopes of carbon atoms.

The $\text{H}\text{NMR}$

signal for protons bonded to substituted benzene rings is between $\delta 6$ and $8.5$.

The IR (infrared) spectra of benzene show the absorption occurring at $\text{3030 cm}$ for the stretching of $\text{C-H}$

bond. Further, the monosubstituted benzene results in the generation of peaks in the range of $\text{690}$ and $\text{710 cm}$, and in the range of $\text{730}$ and $\text{770 cm}$. The $\text{O-H}$

group gives a broad peak at ${\text{3550-3200 cm}}^{-\text{1}}$.