CHAPTER 13 Unsaturated Hydrocarbons General, Organic, & Biological Chemistry

1. CHAPTER 13 Unsaturated Hydrocarbons General, Organic, & Biological Chemistry Janice GorzynskiSmith

2. CHAPTER 13: Unsaturated Hydrocarbons • Learning Objectives: • Identify unsaturated hydrocarbons: alkenes, alkynes, aromatic compounds • Alkene, Alkyne, Aromatic nomenclature • Stereoisomers • Addition Reactions • Polymers • Substitution Reactions Smith. General Organic & Biolocial Chemistry 2nd Ed.

3. Functional Groups Overview Alkane Alkene Alkyne Aromatic C − C C = C C = C Hydrocarbon Functional Groups Smith. General Organic & Biolocial Chemistry 2nd Ed.

4. Hydrocarbon Chemical formulas CnH2n+2 if a chain CnH2nif a cycloalkane Alkane Alkene Alkyne Aromatic C − C C = C C = C CnH2n if a chain with 1 dbl bond CnH2n-2if a cycloalkene with 1 dbl bond CnH2n-2 if a chain with 1 triple bond C6H6 Smith. General Organic & Biolocial Chemistry 2nd Ed.

5. Molecule Shape Drawing Alkenes SIMPLIFY! H H H H .. H C C C C H H H H CH3CH2CH2=CH2 Smith. General Organic & Biolocial Chemistry 2nd Ed.

6. Nomenclature Alkanes 6 4 2 3 5 1 + + prefix parent suffix What, where are the substituents? Example: 2,4- dimethyl prefix How many carbons in longest chain? Example: hex parent What is the functional group? Example: ane suffix 2,4-dimethylhexane Smith. General Organic & Biolocial Chemistry 2nd Ed.

7. Nomenclature Alkenes & Alkynes 6 4 2 3 5 1 + + prefix parent suffix First give location and type of substituents Second give location of double bond prefix How many carbons in longest chain? parent How many of the functional group and what is it? Alkene = ene; Alkyne = yne suffix 2,4-dimethyl 1,5- hexa diene * Note: when we have more then 1 multiple bond the parent name has an “a” added on: hexa instead of hex Smith. General Organic & Biolocial Chemistry 2nd Ed.

8. Nomenclature Alkenes & Alkynes 1 3 2 4 5 + + prefix parent suffix First give location and type of substituents Second give location of double bond prefix How many carbons in longest chain? parent How many of the functional group and what is it? Alkene = ene; Alkyne = yne suffix 4-methyl 2- pent yne Smith. General Organic & Biolocial Chemistry 2nd Ed.

9. Nomenclature Alkenes & Alkynes 4 5 3 2 1 + + prefix parent suffix First give location and type of substituents Second give location of double bond prefix How many carbons in longest chain? parent How many of the functional group and what is it? Alkene = ene; Alkyne = yne suffix cyclo pent ene 3-methyl 1- Smith. General Organic & Biolocial Chemistry 2nd Ed.

10. Nomenclature Aromatics: Benzene 5 6 o - m - p - 1 2 4 3 + prefix parent Give location, number, and type of substituent. You can also replace location & number with o, m, p prefix parent “Benzene” Polysubstituted Benzenes: Number to give lowest #s around ring Alphabetize substituents If part of common root name the molecule as a derivative of a monosubstituted benzene with common root at C1. 1,2-dimethyl benzene o-dimethyl benzene Smith. General Organic & Biolocial Chemistry 2nd Ed.

11. Group Problem Practice naming Alkenes & Alkynes!

12. Bond Angles Alkenes & Alkynes 120° ethylene 180° acetylene

13. Alkenes Stereoisomers R R R R CIS TRANS

14. Alkenes Stereoisomers Linoleic Acid

15. Alkenes Stereoisomers Stereoisomers Different 3-D shape Same bonds Conformational Isomers Different bonds between atoms

16. Alkene Reactions Addition Addition Rxns: when elements are added to a compound X Y X Y

17. Alkene Reactions Addition H H H2 Metal catalyst Hydrogenation X X X2 X = Cl or Br Halogenation X H HX X = Cl or Br Hydrohalogenation H2O H2SO4 Hydration H OH

18. Nucleophile vs Electrophile Smith. General Organic & Biolocial Chemistry 2nd Ed.

19. Alkene Reactions Polymers Polymerization: joining together of monomers

20. Aromatic Reactions Substitution Substitution Rxns: when an atom is replaced by another atom or group of atoms H X X Y H Y

21. Aromatic Reactions Substitution Cl Cl2 Clorination H NO2 HNO3 H2SO4 Nitration SO3H SO3 H2SO4 Sulfonation