The formal hybridization of the carbon bearing the negative charge in a delocalized allyl carbanion — GOC and Organic Chemistry Basics Chemistry Question

💡 Solution & Explanation

While an isolated localized carbanion is $sp^3$ hybridized, a carbanion adjacent to a $\pi$ -system rehybridizes to $sp^2$. This places the lone pair into a pure p-orbital, allowing it to overlap parallel with the $\pi$ -bond for massive resonance stabilization.