Q. Among $BMe_{3},\ BF_{3},BCl_{3}\ and\ B_{2}H_{6}$ which one will be the best Lewis acid?
A) ${BCl}_{3}$
B) ${BMe}_{3}$
C) $B_{2}H_{6}$
D) ${BF}_{3}$
Explanation
(a)
(i)$BF_{3}\ and\ BCl_{3}$ are better Lewis acid than $BMe_{3}$ and $B_{2}H_{6}$ due to –$I$-effect of $Cl\ and\ F$.
(ii)Between $BCl_{3}\ and\ BF_{3},BCl_{3}\$is better Lewis acid due to lesser extent of $p\pi - p\pi$ back bonding in it.
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.