Benzene C 6 H 6

1. 3 2 0 - Benzene C6H6 Miles Selvidge

2. Table of Contents • Stats • Structure • Bonding • Electronic Properties • Reactions • Nomenclature • Industry • Harmful Effects Miles Selvidge

3. Statistics • Discovered by Michael Faraday - 1825 • Most Basic Aromatic Molecule • Colorless Liquid • Boiling Point: 80.08oC • Melting Point: 5.48oC • Density: .880 g/cm3 Miles Selvidge

4. Statistics -continued • Insoluble in Water • Soluble in Oils & Fats • Explosive Vapors • Flammable Liquid Miles Selvidge

5. Structure • Flat Structure • Carbon Atoms are sp2 Hybridized • Carbon has Triangular Planar Geometry Miles Selvidge

6. Bonding • Sigma and pi Bonding between Carbon atoms • Has Resonance Structure ==> • Actual Bonds are All Intermediate Length • Increased Stability Miles Selvidge

7. Electronic Properties • The Six Electrons in the pi Bonds are Loosely Held Compared to the Electrons in the sigma Bonds • Those Six Electrons are Delocalized • This causes a cloud of electrons above and below the plane of the benzene molecule Miles Selvidge

8. Reactions • The Resonance Structures of Benzene Increase its Stability • Resist Addition Reactions Because That Would Destroy the Ring Structure • Often Undergoes Substitution Reactions • Benzene Serves as a Source of Electrons for Electrophilic Reagents Miles Selvidge

9. Reactions - Types of Substitutions • Nitration: C6H6 + HNO3 C6H6NO2 + H2O • Halogenation: Carbon Replaced by Halogen • Sulfonation: Carbon Replaced by Sulfer • Friedel-crafts: Acyl group (RCO-) Attaches to Ring to Make a Keytone Nitrobenzene Miles Selvidge

10. Nomenclature of Benzene • When Substituent Takes its Place in the Ring the New Molecule’s name is the prefix -benzene • Ex: Chlorobenzene Miles Selvidge

11. Nomenclature- Continued • If More Than One Group Attaches to Benzene then Positions Must be Indicated • Ortho () = One Space • Meta (m) = Two Spaces • Para (p) = Three Spaces CH3 NO2 -Nitrotoluene NO2 M-Chloronitrobenzene Cl I p-Bromoiodobenzene Br Miles Selvidge

12. Nomenclature - continued • -Nitrotoluene • m-Chloronitrobenzene • p-Bromoiodobenzene Miles Selvidge

13. Nomenclature - continued • If 3 or More Groups Attach • Numbers are Used to Indicate Positions • 2-Chloro-4-nitrophenol OH 1 Cl 6 2 5 3 4 NO2 Miles Selvidge

14. Industry • Made from Coal Tar (a liquid left over when coal is heated) and Petroleum • Used as a Source for Almost all Aromatic Compounds • Make Complicated Aromatic Compounds by Taking Benzene and Add on Other Rings Piece by Piece Miles Selvidge

15. Industry - continued • Solvent for: • Sulfur, Phosphorus and Iodine • Gums • Fats, Waxes and Resins • Simple Organic Compounds • One of the Most Commonly Used Solvents in Organic Chemistry Miles Selvidge

16. Aniline: Dye (Aniline Oil) Plastics Drugs (Sulfanilamide) Explosives Phenol: Disinfectant Antiseptic (Diluted) Insecticide Explosives Detergent Raw Material for Aspirin Industry - continued • Can Make Aniline and Phenol Miles Selvidge

17. Industry - continued • Makes Toluene, a component of TNT (Trinitrotoluene) • Makes Tear Gas • Makes Acetone Miles Selvidge

18. Toxic Nature • Carcinogen -- Causes Leukemia • Makes Dioxins • Two Phenols Combine and Cl Connects to Make Chlorinated Dibenzo-p-dioxin • Does not Dissolve in Water, but does in Oils and Fats • Accumulates in the Food Web • Mimics Hormones • Disrupts Normal Functions and Growth Miles Selvidge