Why is vinyl carbocation unstable?
Vinyl carbocation is unstable.
A vinyl cation is a positively charged molecule (a cation) where the positive charge is located on a vinyl group (−CH=CH2).
The hybridization of a vinyl carbocation is sp hybirdized. Carbon with two other atoms attached prefers sp hybridization and a linear geometry.
The vinyl cations are less stable due to the difference in hybridization of the carbon bearing the positive charge. Vinyl cations are located on sp hybridized carbons. Since sp hybridized carbons have less p-character they are not able to donate more electrons to the positive charge located in the empty p-orbital, thus destabilizing it.