In general: Charged species are of lower energy (more stable) if their charge is delocalised over more atoms.
Carbocations are classified according to the number of saturated carbon atoms bonded to the carbon bearing the positive charge. The charge density (electrostatic potential) maps indicate through the blue colour that the positive charge is delocalised to a greater extent on tertiary and secondary carbocations. Thus alkyl groups are better able to delocalise charge than the hydrogens.
Carbocations are classified according to the number of saturated carbon atoms bonded to the carbon bearing the positive charge. The charge density (electrostatic potential) maps indicate through the blue colour that the positive charge is delocalised to a greater extent on tertiary and secondary carbocations. Thus alkyl groups are better able to delocalise charge than the hydrogens.
 | 2CHPlus.jpg) |
| primary (one carbon attached) | secondary (two carbons attached) |
3CPlus.jpg) |
| tertiary (three carbons attached) |