Class 11 Chemistry Notes GOC – Carbanion

Carbanion:  A Carbanion is an anion in which carbon has an unshared pair of electrons and holds a negative charge generally with three groups for eight valence electrons

1. It is a negative charged species
2. It has octet of electrons
3. Diamagnetic in Nature.

Structure:

• If negative charge is in Resonance then, Hybridization of Carbanion is sp2 (Triangular Planer Shape)
• If negative charge is not in Resonance then the Hybridization of Carbanion is sp3 (pyramidal)

Stability:

Its stability can be determined with the help of

1. Inductive effect
2. Resonance effect

Ex.1 

Stability of the carbocation is as follows

Ex.2 Compare the stability of the following Carbanion

(a)  
(b) 
(c) 

Sol.      c > a > b (Stability)

Ex.3 Compare the stability of the following Carbanion

1. -CH2CF3
2. -CH2Cl3
3. -CH2CBr3

Sol. a > b > c

Ex.4 Arrange the following anion ion order of their stability

1. Cl-
2. Br-
3. F-
4. I- (Maximum size)

Maximum dispersion negative charge
Maximum stability

Sol. d > b > a > c

Ex.5 Compare the Stability of the following

1. -CH3
2. -NH2
3. -OH
4. F-

Sol. Same period element (C, N, O, F)
⇒Stability ∝ E.N. of the atom
a > c > b > a

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