Chapter 16, Problem 16.33SP

Azulene is a deep-blue hydrocarbon with resonance energy of 205 kJ/mol (49 kcal/mol). Azulene has ten pi electrons, so it might be considered as one large aromatic ring. Its electrostatic potential map shows one ring to be highly electron-rich (red) and the other to be electron-poor (blue). The dipole moment is unusually large (1.0 D) for a hydrocarbon. Show how this charge separation might arise.