Although F has high -I effect, yet `F_(3)C^(+)` is more stable . Explain why is it so ?

Explanation

In carbocation, , the strongly electron withdrawing `Fe_(3)C-` group withdraws electrons of the C-C bond towards itself thereby intensifying the +ve charge and thus destabilising the carbocation.

On the other hand, in carbocation `F_(3)C^(+)`, the lone pair of electrons on each of the three F-atoms overlap with the empty 2p-orbital of the carbon atom carrying the +ve charge thereby dispersing the +ve charge and thus stabilizing the carbon, `F_(3)C^(+)` relative to .