Write the hybridisation & structure of carbon in carbocation & carbanion
The Correct Answer and Explanation is:
Hybridization and Structure of Carbon in Carbocation and Carbanion:
Carbocation (C+) Hybridization:
In a carbocation, the carbon atom carries a positive charge, resulting in a deficiency of electrons. The carbon in a carbocation has only three bonds, leading to the need for three electron pairs to form bonds. This gives it a sp² hybridization.
Explanation:
- The carbon atom in a carbocation undergoes sp² hybridization, meaning it mixes one s orbital and two p orbitals to form three equivalent sp² hybrid orbitals.
- These three sp² hybrid orbitals are arranged in a trigonal planar geometry, with bond angles of approximately 120° between them.
- The third p orbital remains unhybridized and contains the empty orbital, which gives the carbon atom its positive charge.
- The empty p orbital of the carbon can overlap with adjacent p orbitals of other atoms or molecules, creating the possibility for electrophilic attack.
The structure of the carbocation is planar with three substituents or bonds arranged in a trigonal plane around the central carbon atom.
Carbanion (C-) Hybridization:
A carbanion carries a negative charge on the carbon atom, meaning it has an extra pair of electrons. The carbon in a carbanion has four bonds and an extra lone pair of electrons. This leads to sp³ hybridization.
Explanation:
- The carbon atom in a carbanion undergoes sp³ hybridization, meaning it mixes one s orbital and three p orbitals to form four equivalent sp³ hybrid orbitals.
- These four orbitals arrange themselves in a tetrahedral geometry, with bond angles of approximately 109.5° between them.
- One of the sp³ hybrid orbitals holds the lone pair of electrons, while the other three are used to form bonds with surrounding atoms or groups.
- The negative charge is localized on the carbon atom and occupies one of the hybrid orbitals. This gives the carbanion a more concentrated electron density around the carbon.
The structure of the carbanion is tetrahedral with the negative charge being localized on the carbon.
Summary:
- Carbocation: sp² hybridization, trigonal planar geometry.
- Carbanion: sp³ hybridization, tetrahedral geometry.
