Question

The strongest base among the following is

• A. $C_6{H}_{5}N{H}_2$
• B. $(C_6{H}_5{)}_{2}NH$
• C. ${(C{H}_3)}_{3}N$
• D. ${(C_2{H}_5)}_{2}NH$
• E. ${(C_2{H}_5)}_{2}N{H}^{+}C{l}^{-}$

Answer 1

Answer: (D)

${(C_2{H}_5)}_2\stackrel{\bullet \bullet }{N}H$ ( $2{}^{\circ }$ amine) is strongest base. Basic nature of amines due to presences of lone pair of electron on nitrogen atom which is available for the bond formation with Lewis acid. Due to the + $I$ effect $2{}^{\circ }$ amine is better base than $1{}^{\circ }$ amine and $N{H}_3$ . In case of aromatic amines the lone pair on nitrogen atom involved in resonance, therefore, not available for bond formation, so aromatic amines are less basic.