Carbocations and carbanions are two types of organic chemical species that differ in terms of their electronic charge and reactivity.
Carbocation:
A carbocation is a positively charged carbon ion.
It has an empty p orbital, making it electron-deficient and highly reactive.
The carbon atom in a carbocation is trivalent, with only three bonds and a vacant orbital.
Carbocations are formed when a carbon atom loses a bonding pair of electrons, resulting in a positive charge on the carbon.
They are often represented as follows: R3C^+ (where R represents various organic groups).
Due to their electron deficiency, carbocations are strong electrophiles and readily react with nucleophiles.
Carbanion:
A carbanion is a negatively charged carbon ion.
It has an additional electron, making it electron-rich and reactive.
The carbon atom in a carbanion is tetravalent, having four bonds and a lone pair of electrons.
Carbanions are formed when a carbon atom gains an extra electron, resulting in a negative charge on the carbon.
They are often represented as follows: R3C^- (where R represents various organic groups).
Due to their excess of electrons, carbanions are strong nucleophiles and participate in nucleophilic substitution and addition reactions.
In summary, carbocations are positively charged carbon ions with an electron deficiency and act as electrophiles, while carbanions are negatively charged carbon ions with an excess of electrons and behave as nucleophiles. The difference in electronic charge and reactivity between the two species plays a crucial role in organic chemistry reactions and mechanisms.