Chapter 15, Problem 75IP

Interpretation Introduction

Interpretation:

The compound that gives the given ${}^{\text{1}}\text{H}$ NMR spectrum has to be identified.

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 ${}^{\text{1}}\text{H,}{}^{\text{13}}\text{C,}{}^{\text{15}}\text{N,}{}^{\text{19}}\text{F}\text{and}{}^{\text{31}}\text{P}$

Chemical shift: The frequency of the proton signal in the spectrum with reference to the standard compound  which may be TMS(Tetramethylsilane) shows signal at 0 ppm(parts per million).

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

Chemical shift values for protons in different electronic environment

Types of protons	Chemical shift
Methyl	$\text{~0}\text{.9}$
methylene	$\text{~1}\text{.2}$
Methine	$\text{~1}\text{.7}$
Allylic	$\text{~2}$
Alkynyl	$\text{~2}\text{.5}$
Aromatic methyl	$\text{~2-5}$
Alkyl halide	$\text{~2-4}$

Alcohol	$~2-5$
Vinyl	$~4.5-6.5$

Aryl	$~6.5-8$
Aldehyde	$~10$
carboxylic	$~12$