Ch. 17 - AromaticitySee all chapters
All Chapters
Ch. 1 - A Review of General Chemistry
Ch. 2 - Molecular Representations
Ch. 3 - Acids and Bases
Ch. 4 - Alkanes and Cycloalkanes
Ch. 5 - Chirality
Ch. 6 - Thermodynamics and Kinetics
Ch. 7 - Substitution Reactions
Ch. 8 - Elimination Reactions
Ch. 9 - Alkenes and Alkynes
Ch. 10 - Addition Reactions
Ch. 11 - Radical Reactions
Ch. 12 - Alcohols, Ethers, Epoxides and Thiols
Ch. 13 - Alcohols and Carbonyl Compounds
Ch. 14 - Synthetic Techniques
Ch. 15 - Analytical Techniques: IR, NMR, Mass Spect
Ch. 16 - Conjugated Systems
Ch. 17 - Aromaticity
Ch. 18 - Reactions of Aromatics: EAS and Beyond
Ch. 19 - Aldehydes and Ketones: Nucleophilic Addition
Ch. 20 - Carboxylic Acid Derivatives: NAS
Ch. 21 - Enolate Chemistry: Reactions at the Alpha-Carbon
Ch. 22 - Condensation Chemistry
Ch. 23 - Amines
Ch. 24 - Carbohydrates
Ch. 25 - Phenols
Ch. 26 - Amino Acids, Peptides, and Proteins

Concept #1: Inscribed Polygon Method

Example #1: Inscribed Polygon Method

Additional Problems
Which of the following best describes the MO diagram of the aromatic cycloheptatriene cation?
Using a Frost circle, draw the molecular orbital energy diagram for the cyclopentadienyl anion and predict if it is aromatic.
Using the polygon rule, draw out and decide whether the following species are aromatic or anti-aromatic.
For the energy diagram shown below:  1) There are 3 antibonding orbitals and 2 bonding orbitals 2) There are 2 antibonding orbitals and 2 non-bonding orbitals and 1 bonding orbital 3) There are 2 antibonding orbitals and  3 bonding orbitals 4) There are 2 antibonding orbitals and 2 non-bonding orbitals and 1 bonding orbital 5) There is 1 bonding orbital and 4 antibonding orbitals    
Which is the proper orbital description of cyclopropene anion?
Pick the correct energy diagram for cyclooctatetraene. In this case, assume the ring is flat. 
Which is the best depiction of the molecular orbitals of imidazole?
The MO diagrams of five compounds are shown below. Which one is anti-aromatic?
Apply the polygon circle method to the following compound. Does it show any special stability? If yes, why?  Benzene
Apply the polygon circle method to the following compound. Does it show any special stability? If yes, why?  Cyclopentadienyl anion
Apply the polygon circle method to the following compound. Does it show any special stability? If yes, why?  Cyclopropenium anion
Apply the polygon circle method to the following compound. Does it show any special stability? If yes, why?  Tropyllium cation
Which of the following molecular orbital diagrams best fits that of pyrrole?