Q21 / 120 · VITEEE 2010 · Chemistry

The one which is least basic is

  • A
    $\mathrm{NH}_{2}$
  • B
    $\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NH}_{2}$
  • Correct answer
    C
    $\left(\mathrm{C}_{6} \mathrm{H}_{5}\right)_{3} \mathrm{~N}$
  • D
    $\left(\mathrm{C}_{6} \mathrm{H}_{5}\right)_{2} \mathrm{NH}$

Solution

Due to the presence of electron withdrawing group like Ph group decreases the electron density of nitrogen and hence, the lone pair of nitrogen are not available, for donation. So, $\left(\mathrm{C}_{6} \mathrm{H}_{5}\right)_{3} \mathrm{~N}$ is least basic due to the presence of three electron withdrawing $\mathrm{Ph}\left(\mathrm{C}_{6} \mathrm{H}_{5}\right)$ groups.

Hence, the correct answer is option: 'C'.

Relevant Questions