Question

The strongest Lewis acid is

• A. $B{F}_3$
• B. $BC{l}_3$
• C. $BB{r}_3$
• D. $B{I}_3$

Answer 1

Answer: (D)

The order of strength of Lewis acid character for boron halides is, $B{F}_3<BC{l}_3<BB{r}_3<B{I}_3$ (due to back bonding)