- You can recognize benzene and substituted examples, provide a proper name for multiply substituted benzenes, or draw a structure from the name of a substituted benzene.
- You understand the thermodynamic explanation of aromaticity derived from heats of hydrogenation of cyclohexene, cyclohexadiene, and benzene. This is the first experimental means of identifying a molecule as aromatic.
- You understand that the origin of this stability for benzene and other aromatic molecules is based on the cyclic array of p atomic orbitals creating a set of molecular orbitals with unusual stability.
Visualization: Pi MOs of Benzene.
- You know Hückel's rule for determining whether a cyclic array of pi electrons is aromatic: 4n + 2 electrons will be aromatic and specially stabilized; 4n electrons will be destabilized and antiaromatic.
- You can classify any molecule as aromatic or antiaromatic (if there is a cyclic array of pi electrons) or nonaromatic (if the pi electrons do not complete a ring).
- You can extend this classification to include carbocations and carbanions by recognizing the participation of a p orbital in the cyclic array.
- You understand the general mechanism for electrophilic aromatic substitution, and can apply it to any electrophile reacting with benzene.
- You know that the observation of electrophilic aromatic substitution (instead of electrophilic addition) is the second major criterion for aromaticity.
- You know reaction conditions for the following electrophilic aromatic substitutions:
- Halogenation
- Nitration
- Sulfonation
- Friedel-Crafts Alkylation
- Friedel-Crafts Acylation
Recommended end-of-chapter problems: 15-38, 15-41, 15-42, 15-47, 15-48, 15-51, 15-59, 15-60, 15-67.
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