13. Benzene and its Derivatives

-benzene or one of its derivative

-alkane, alkene, alkyne

-compound containing one or more benzene rings

-group derived from arene by removal of a H atom and given the symbol Ar–

-discovered benzene (simplest aromatic compound)

-proposed first structure for benzene -six-membered ring with alternating single and double bond

-molecule best described as a composite of two or more Lewis structures -Linus Pauling

-closed loop of six electrons (two from the second bond of each double bond) characteristic of benzene ring

-derivatives of benzene (i.e. ethylbenzene) -usually IUPAC retains common name -toluene, styrene, phenol, anisole, aniline, benzaldehyde, benzoic acid

C6H5—, the aryl group derived by removing a hydrogen atom from benzene -in molecule containing other functional groups, phenyl group are often named as substituent (i.e. 4-Phenyl-1-butene)

-3 isomers possible -locate substituents by either numbering or locators • ortho (o) 1,2- (Greek straight) • meta (m) 1,3- (after) • para (p) 1,4- (beyond) -when one substituents impart special name to compound (i.e. —CH3, —OH, —NH2, —COOH), name the compound as a derivative of that parent molecule. That substituent occupies number 1 (i.e. 4-bromobenzoic acid, 3-chloroaniline, 1,3-dimethylbenzene)

-specify locations by numbers -when one substituents impart special name to compound, name the compound as a derivative of that parent molecule. That substituent occupies number 1 -when none imparts special name, locate substituents before ending benzene

-contains two or more benze rings, each of which shares teo carbon atoms with another benzene ring -imagine honeycomb -naphthalene, anthracene, phenanthrene

-substitution at a ring carbon (Aromatic substitution)

-in the presence of iron catalyst Benzene + Cl2 ➡️ chlorobenzene

-heat benzene or its derivatives with mixture of concentrated nitric and sulfuric acid, hydrogen atom bonded to ring is replaced by a nitro (-NO2) group

-heating aromstic compound with concentrated sulfuric acid results to ARENESULFONIC ACID (strong acids) -preparation of synthetic detergents

-compound containing –OH group bonded to benzene ring -named as derivatives of phenols or by common name (3-methylphenil, 1,2-benzenediol) -weak acids

-oxidation requiring oxygen and no other reactant -radical chain proces that converts an R—H group to R—O—O—H group (HYPEROXIDE)

-number of times the cycle of chain propagation steps repeats