They can be obtained by the decomposition of diazonium salts, or by the solvolysis of alkyl halides, and since they have a planar geometry, their occurrence at bridgehead positions is controversial.
The first one of these to be directly observed was obtained by the solution of TBF in an antimony-based superacid. That experiment was performed by the man who developed NMR solvents such as "magic acid" and sulfur dioxide for studying these compounds, George Olah. Reactions wherein these intermediates are formed can see the shift of the functional group at the beta position, which is named for (*) Wagner and Meerwein. "Bridged" versions of these contain hydride or alkyl groups which exhibit partial bonding with two other carbon atoms. They can be obtained by the decomposition of diazonium salts, or by the solvolysis of alkyl halides, and since they have a planar geometry, their occurrence at bridgehead positions is controversial. For 10 points, identify this type of compounds wherein a carbon atom has a positive charge, whose tertiary ones are usually the most stable.
The first one of these to be directly observed was obtained by the solution of TBF in an antimony-based superacid.
{carbocation} [accept {carbonium ion} ]