Benzene and Aromaticity

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Benzene and Aromaticity
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Bonding in Benzene
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Proposed Benzene Structures
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C6H6 reacts with HBr to form one isomer of C6H5Br
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Other Conjugated Hydrocarbon RingsAnnulenes
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DHhyd Data Illustrates Stability
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Benzene Representations
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Molecular Orbitals of Benzene
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M.O.s of Cyclobutadiene
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6 p Electrons is Stable4 or 8 p Electrons is not
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Huckels Rule 4N 2
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In Order to Exhibit Aromaticity a Compound Must

• -         Cyclic
• -         Planar
• -         Conjugated throughout
• -         Has a Huckel of p electrons
• o       4N 2 where N is any integer or 0
•          hence, 2,6,10,14 p e-

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Naphthalene
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Pyridine, an Aromatic Heterocycle
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Pyridine as a Base
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Pyrrole
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Pyrrole as a Base
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Other Aromatic Heterocycles
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Cyclopentadiene as an AcidpKa 16
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Cyclopentadienyl ionOne is Aromatic, one is
Antiaromatic
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Resonance Depictions of the Ions
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Tropylium Ion
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Aromatic?
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Aromatic, Anti-Aromatic or Nonaromatic?
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Some Well-known Aromatic Compounds
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Designer Drugs
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Nomenclature
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Disubstitutionortho, meta and para
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Disubstitution Nomenclature
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Aromatic Template Names
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More Common Names
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Aromatic Ring as a Substituent
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Name These
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