Chapter 9, Problem 23P

Interpretation Introduction

Interpretation:

The structures for the compounds G and H are to be proposed.

Concept introduction:

The basic principle of NMR is that nuclei having spin value greater than zero when placed in an external magnetic field is applied, an energy transfer occurs between the base energy to the higher energy level A few elements such as ${}^{13}{\text{C and }}^1\text{H}$ have nuclei that behave as magnets about an axis, which are placed in a magnetic field irradiated with electromagnetic energy of a specific frequency. Then, the nuclei tend to absorb energy via magnetic resonance. The graph that shows the energy absorption frequencies and intensities of a sample kept in the magnetic field is called nuclear magnetic resonance (NMR).

Chemical shift is the measurement on the $\delta$ scale (in ppm) where the peaks appears when the nuclei absorb energy through magnetic resonance. The reference compound for proton NMR is tetramethylsilane