Chapter 15, Problem 51PP

Interpretation Introduction

Interpretation: For the given set of compounds the chemical shift values to be compared and arranged in an increasing order.

 Concept Introduction:

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).

$\text{Chemical}\text{shift}\text{=}\frac{\text{signal}\text{frequency-}\text{reference}\text{frequency}}{\text{frequency}\text{of}\text{spectrometer}}\left({\text{10}}^{\text{6}}\right)$

Bench mark values for protons in different electronic environment:

Types of protons	Chemical shift
Alkynyl	$\text{~2}\text{.5}$
Vinyl	$~4.5-6.5$
Aryl	$~6.5-8$