Some Basic Principles Of Organic Chemistry Question 172
Question: Most stable carbonium ion is [Pb. CET 2004]
Options:
A) $ {{\overset{+}{\mathop{C}},}_2}H_5 $
B) $ {{(CH_3)}_3}\overset{+}{\mathop{C}}, $
C) $ {{(C_6H_5)}_3}\overset{+}{\mathop{C}}, $
D) $ C_6H_5\overset{+}{\mathop{C}},H_2 $
Show Answer
Answer:
Correct Answer: C
Solution:
In the triphenyl methyl carbonium ion the p electrons of all the three benzene rings are delocalised with the vacant p-orbital of central carbon atom.
So, it is resonance stabilised.
It is the most stable of all the carbonium ions given The ion $ CH_3-\underset{CH_3}{\overset{CH_3}{\mathop{\underset{|\ \ }{\overset{|\ \ }{\mathop{{C^{+}}}}},\ \ }}}, $ is stabilised by hyperconjugation, a second order resonance.
