Chapter 16, Problem 16.5YT

Interpretation Introduction

Interpretation:

The chemical shifts for the protons in ${\text{FCH}}_{\text{3}}$, ${\text{ClCH}}_{\text{3}}$, and ${\text{BrCH}}_{\text{3}}$ in Table $\text{16-1}$ are to be compared with the electronegativities of fluorine, chlorine, and bromine in Figure $\text{1-16}$. Whether the trends are the same or different is to be determined.

Concept introduction:

The higher the electronegativity difference between H and its surrounding atoms, the higher the chemical shift. This is because the higher the electronegativity difference between H and another atom, the lower the electron density around the H (proton), and thus, the more deshielding the proton experiences.