| Watch as the benzene ethyl carbanion is rotated in 3-d space, showing how the carbanion is sp2-hybridized, which allows a filled p-orbital to be in conjugation with the rest of the molecule. The highest occupied molecular orbital (HOMO) indicates that the real molecule (resonance hybrid) really looks like there's a carbanion at four different locations (can you draw all resonance structures?). Lastly, notice how the electron density plot shows the red hotspot (charge density) located at the benzylic carbon, and the two ortho carbons, and para carbon. |