Chapter 18 Organic Chemistry

1. Chapter 18 Organic Chemistry

2. Objectives • 18.1Write and interpret structural formulas of linear, branched, and cyclic alkanes, alkenes, and alkynes • 18.1 Distinguish among isomers of a given hydrocarbon • 18.1 Infer the relationship between fossil fuels and organic chemicals

3. Objectives • 18.2Compare and contrast the structures of the major classes of substituted hydrocarbons • 18.2 Summarize properties and uses of each class of substituted hydrocarbons • 18.3 Identify monomers that form specific polymers; draw structural formulas for polymers made from given monomers.

4. Objectives • 18.3Differentiate between condensation and addition polymerization reactions • 18.3 Summarize the relationship between structure and properties of polymers

5. Quiz 1 Organic Chemistry • Naming of Organic Molecules • Anes, enes, ynes, cyclic, substituted including halogens and alcohols • Drawing of Organic Molecules • Differences and General properties between Alkanes, Alkenes, Alkynes, and Aromatic Organic Molecules

6. Quiz 2 Organic Chemistry • Isomers • Organic Reactions • Functional Groups (by memory) • Biological Connection • Proteins, Carbohydrates, Lipids, Nucleic Acids

7. Organic Chemistry • The chemistry of carbon compounds. • Carbon has the ability to form long chains. • Without this property, large biomolecules such as proteins, lipids, carbohydrates, and nucleic acids could not form.

8. Hydrocarbons • Four basic types: • Alkanes • Alkenes • Alkynes • Aromatic hydrocarbons • With many different functional groups

11. Alkanes • Only single bonds. • Able to rotate freely (unlike other groups) • Saturated hydrocarbons. • “Saturated” with hydrogens. • Unreactive (unlike other groups

12. Structure of Alkanes • Tetrahedral geometry. • 109.5° bond angles.

13. Structure of Alkanes • Free rotation about C—C bonds.

15. Alkenes • Contain at least one carbon–carbon double bond. • 120 degree angles • Unsaturated. • Have fewer than maximum number of hydrogens. • More reactive than alkane, less than alkyne

16. Structure of Alkenes • Unlike alkanes, alkenes cannot rotate freely about the double bond. • Fixed bond • Reactive bonds (useful for digestion)

18. Alkynes • Contain at least one carbon–carbon triple bond. • Also unsaturated (more unsaturated) • More reactive then alkenes

19. Formulas • Lewis structures of alkanes look like this. • Also called structural formulas. • Skeletal when only carbon and groups drawn

20. Formulas condensed formulas are useful at times

21. Cycloalkanes • Carbon can also form ringed structures. • Five- and six-membered rings are most stable. • Can take on conformation in which angles are very close to tetrahedral angle. • Smaller rings are quite strained.

22. Aromatic Hydrocarbons • Cyclic Carbon chain of 6 with double bonds shared amongst the center

23. Aromatic Nomenclature Many aromatic hydrocarbons are known by their common names.

24. Reactions of Aromatic Compounds • Electrons are delocalized; this stabilizes aromatic compounds. • Middle electrons are shared

25. Structure of Aromatic Compounds • Two substituents on a benzene ring could have three possible relationships • O(ortho)-: On adjacent carbons. • M(meta)-: One carbon between them. • P(para)-: On opposite sides of ring.

26. Properties of Alkanes • Boiling point increases with length of chain.

27. Your typical soap

28. Organic Nomenclature • Three parts to a compound name: • Base: Tells how many carbons are in the longest continuous chain.

29. Organic Nomenclature • Three parts to a compound name: • Base: Tells how many carbons are in the longest continuous chain. • Suffix: Tells what type of compound it is.

30. Organic Nomenclature • Three parts to a compound name: • Base: Tells how many carbons are in the longest continuous chain. • Suffix: Tells what type of compound it is. • Prefix: Tells what groups are attached to chain.

31. To Name a Compound… • Find the longest chain in the molecule. • Number the chain from the end nearest the first substituent encountered. • List the substituents as a prefix along with the number(s) of the carbon(s) to which they are attached. • Ending becomes - yl

32. Nomenclature of Alkynes 4-methyl-2-pentyne • Analogous to naming of alkenes. • Suffix is -yne rather than –ene.

33. Nomenclature of Alkenes • Chain numbered so double bond gets smallest possible number. • cis- alkenes have carbons in chain on same side of molecule. • trans- alkenes have carbons in chain on opposite side of molecule.

34. Organic Prefixes (Important Slide) • Meth = 1 Hex = 6 • Eth = 2 Hept = 7 • Prop = 3 Octa= 8 • But = 4 Non =9 • Penta = 5 Dec = 10

35. To Name a Compound… If there is more than one type of substituent in the molecule, list them alphabetically.

48. Quiz 2 Organic Chemistry • Isomers • Organic Reactions • Functional Groups (by memory) • Biological Connection • Proteins, Carbohydrates, Nucleic Acids

49. Functional Groups Term used to refer to parts of organic molecules where reactions tend to occur.

50. Note • For second quiz, you will recognize structures by name and vice versa • A vocabulary if you will • Don’t need to know general info about them (except OH/F)