1. Benzene and Aromaticity

2. Bonding in Benzene

3. Proposed Benzene Structures

4. C6H6 reacts with HBr to form one isomer of C6H5Br

5. Other Conjugated Hydrocarbon Rings Annulenes

6. DHhyd Data Illustrates Stability

7. Benzene Representations

8. Molecular Orbitals of Benzene

10. M.O.’s of Cyclobutadiene

11. 6 p Electrons is Stable 4 or 8 p Electrons is not

12. Huckel’s Rule: 4N + 2

13. 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-

14. Naphthalene

15. Pyridine, an Aromatic Heterocycle

16. Pyridine as a Base

17. Pyrrole

18. Pyrrole as a Base

19. Other Aromatic Heterocycles

20. Cyclopentadiene as an Acid pKa = 16

21. Cyclopentadienyl ion: One is Aromatic, one is Antiaromatic

22. Resonance Depictions of the Ions

23. Tropylium Ion

24. Aromatic?

25. Aromatic, Anti-Aromatic or Nonaromatic?

26. Some Well-known Aromatic Compounds

27. Designer Drugs

28. Nomenclature

29. Disubstitution ortho, meta and para

30. Disubstitution Nomenclature

31. Aromatic Template Names

32. More Common Names

33. Aromatic Ring as a Substituent

34. Name These