Question

Which of the following is the most stable ion?

• A. $P{h}_3\stackrel{+}{C}$
• B. $P{h}_2\stackrel{+}{C}H$
• C. $C{H}_3\stackrel{+}{C}{H}_2$
• D. $Ph\stackrel{+}{C}{H}_2$

Answer 1

The correct option is A $P{h}_3\stackrel{+}{C}$

Phenyl group shows more +I effect than methyl group. Hence it will stabilise the carbocation more.
Triphenyl methyl cation has three benzene resonating ring so it is the most stable ion.
the correct order of stability is
$P{h}_3\stackrel{+}{C}>P{h}_2\stackrel{+}{C}H>Ph\stackrel{+}{C}{H}_2>C{H}_3\stackrel{+}{C}{H}_2>$