Destabilized Carbocations

Carbocations are intrinsically reactive species, and in early studies of their generation and properties the more accessible with stabilizing influences were naturally the prime objects of interest. Now, however, it is possible to extend the scope of these studies to include factors which tend to destabilize carbocations. By using the carbocations CH and C₂H as reference ions, such destabilizing factors can be defined; these include various structural factors, antiaromaticity effects, and the presence of electron-withdrawing substituents. Such factors can be studied by their effect on the thermodynamics of carbocations, their effect on reactivities, and by the spectroscopic properties of long-lived carbocations. Destabilized carbocations of this type are receiving increasing attention and promise to remain an active subject of investigation.