Structural Properties: What do aspirin, Tylenol, ibuprofen, almonds, vanilla, and mothballs have in common? aspirin Tylenol ibuprofen almonds vanilla mothballs Structural Properties: Planar All C atoms sp2 hybridized All C-C bonds equal length Aromatic ring  electrons “smeared out” Resonance structures

Structure of Benzene H H C C Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 212

Benzene 3-D VSEPR Diagram Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 212

Special Stability (aromaticity) Aromatic Compounds Benzene, C6H6 Toluene Phenol Chemical Properties Special Stability (aromaticity) No addition reactions Hf Aniline -156 kJ/mol Aromatic substituents: + 118 kJ/mol -38 kJ/mol phenyl + 113 kJ/mol 75 kJ/mol - 26 kJ/mol benzyl 49 kJ/mol

Benzene C6H6 Uses: styrene; phenol; synthetic detergents; cyclohexane for nylon; DDT; insecticides; fumigants; solvent; paint removers; rubber cement; antiknock gasoline

Names of monosubstituted benzene rings Chlorobenzene Toluene Bromobenzene Phenol Nitrobenzene Styrene

Phenol, (carbolic acid) C6H5OH Uses: solvent for refining lubricating oils; salicylic acid; phenoltpthalein; germicidal paints; pharmaceuticals; laboratory reagent; slimicide Derivative: ~75% of the phenol produced in the United States is made by the oxidation of cumene, yielding acetone as a by-product.

Benzene NO3- Nitrobenzene Using Computational Chemistry to Explore Concepts in General Chemistry Mark Wirtz, Edward Ehrat, David L. Cedeno* Department of Chemistry, Illinois State University, Box 4160, Normal, IL 61790-4160 Mark Wirtz, Edward Ehrat, David L. Cedeno*

Aromatic Hydrocarbons Kelter, Carr, Scott, Chemistry A World of Choices 1999, page 430

Cholesterol Compounds

CH3 C C C C ortho C C para meta position number name 1, 2 ortho- (o-) 6 C C 1 C C ortho 5 2 C C 3 4 para meta position number name 1, 2 ortho- (o-) 1,3 meta- (m-) 1,4 para- (p-)

ortho-dimethylbenzene C H CH3 6 1 5 2 3 4 ortho-dimethylbenzene or 1, 2 - dimethylbenzene

meta-dimethylbenzene C H CH3 6 1 5 2 3 4 meta-dimethylbenzene or 1, 3 - dimethylbenzene

para-dimethylbenzene C H CH3 6 1 5 2 3 4 para-dimethylbenzene or 1, 4 - dimethylbenzene

C H MD 6 1 5 2 3 4 para-docs or paradox

C H MD 6 1 5 2 3 4 ortho-docs or orthodox

C Fe2+ 6 1 5 2 3 4 ferrous wheel or ferris wheel

C H NO2 o - dinitrobenzene or 1, 2 - dinitrobenzene

C CH3 NO2 H O2N Toluene 2,4,6 - trinitrotoluene or TNT

2,4,6 -Trinitrotoluene CH3C6H2(NO2) 3 Uses: Explosives; intermediate in dyestuffs and photographic chemicals Will detonate only if vigorously shocked or heated to 450oF

2, 4, 6 -trichloromethylbenzene Cl CH3 H Toluene 2, 4, 6 - trichlorotoluene or 2, 4, 6 -trichloromethylbenzene

O H O C CH3 C C H C C COOH C C H H 2-acetyloxybenzoic acid or (acetylsalicylic acid or aspirin)

dichlorodiphenyltrichloroethane Cl C C C C C Cl Cl C CCl3 C C C C H H H H dichlorodiphenyltrichloroethane or DDT

H CH CH2 C C H C C H C C H H phenyl ethene or styrene poly a.k.a. (styrofoam)