Acid-Base Properties and Charge Delocalization. II

Electron delocalization can dictate the site of chemical reaction within a molecule. Consider, for example, two alternative acid-base reactions for imidazole  

Both protonated forms place the formal positive charge on one of the nitrogens. Is charge delocalization more effective for one of the structures over the other, making it the more stable  

Compare atomic charges and electrostatic potential maps for imidazole NH protonated and imidazole Nprotonated. In which ion is the positive charge more delocalized Compare carbon-nitrogen bond distances in each ion to those in imidazole as a standard. Are these distances consistent with the bonding patterns shown above for each ion Draw whatever Lewis structures are needed to describe each ion s geometry and charge distribution. 

Obtain the energy of each ion. Which one is more stable Is the delocalized ion more stable  

Which nitrogen in imidazole would you predict to be more basic  

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