Question
Why carbanions are very negative? Discuss the structure of carbanion.
Solution
Their reactivity is due to the fact that the negatively charged carbon in them has got a lone pair of electrons. It has a strong tendency to donate this pair to some electron deficient species.
Therefore, carbanion possesses one unshared pair of electrons and three pairs of covalent bonding electrons around the central carbon atom having a negative charge. Thus carbon is sp3 hybridised and shape of the simple carbanion appears to be pyramidal. Due to the presence of nonbonding electrons pair, the bond angle is reduced to a value slightly lesser than the tetrahedral value of 109.5°.
Therefore, carbanion possesses one unshared pair of electrons and three pairs of covalent bonding electrons around the central carbon atom having a negative charge. Thus carbon is sp3 hybridised and shape of the simple carbanion appears to be pyramidal. Due to the presence of nonbonding electrons pair, the bond angle is reduced to a value slightly lesser than the tetrahedral value of 109.5°.
