Chapter 22

1. Chapter 22 Organic Chemistry!!!!! Chapter 6 in rxn workbook Chapter 16 in PR

2. Organic Chemistry Is….. • The study of carbon containing compounds and their properties • Organic compounds are typically in chains or rings • All organic molecules are produced by living things/systems

3. Vocabulary • Chain • Parent chain and substituent

4. The Name Game …again • Alkanes = hydrocarbons (chains of C and H) • All bonds are single i.e “Saturated” • An alkane is a hydrocarbon in which each carbon atom is bonded to four other carbon or hydrogen atoms.

5. 10 “normal” alkanes

6. The Rest Pentane C5H12 Hexane C6H14 Heptane C7H16 Octane C8H18 Nonane C9H20 Decane C10H22 A note on Boiling Point: BP Octane C8H18      <    Nonane C9H20 More C = more bonds to break and more energy required.

7. Isomers • Same number and type of molecules but bonded in a different location

8. Draw all isomers Pentane 4 2 5 3 1

10. IUPAC International Union of Pure and Applied Chemistry

11. Rules for Naming Alkanes • Read Page 1061 • For chain alkanes beyond butane add the suffix –ane to the Greek root for the number of carbons

12. For Branched alkanes find the longest continuous carbon chain and use this name as the base (a). If two chains of equal length are present, choose the one with the more branch points as the parent.

13. When alkane groups appear as substituent groups they are named by dropping the -ane and adding –yl. • For example CH3 (methane) = methyl . C3H7 is called propyl

14. The position of substituent groups are specified by numbering the longest chain of carbon atoms sequentially starting at the end with the closest branching. C C-C-C-C-C-C 1 2 3 4 5 6 correct numbering 6 5 4 3 2 1 incorrect numbering

15. Last rule! • The location and name of each substituent is followed by the root alkane name. • Substituents are listed in alphabetical order and the prefixes (di, tri,) are used to indicate multiple identical substituents. • A number denotes which carbon that substituent is boned to.

16. Example CH3 CH3 – CH2 - CH – CH2 – CH2 - CH3 1 2 3 4 5 6 3-methylhexane Smallest number for substituent Substituent name Parent chain root name Hyphen between number and substituent name

17. Try some • Draw all structural isomers or C6H14 • Start with the longest chain and then rearrange the carbons to form the shorter CH3-CH2 -CH2 -CH2 –CH2-CH3 1 2 3 4 5 6 Hexane

18. Take one carbon out of the chain and make it a methyl substituent CH3 CH3-CH2 -CH -CH2 –CH3 2 - methylpetane 1 2 3 4 5 CH3 CH3-CH –CH2 -CH2 –CH3 3 - methylpetane

19. Next take two carbons out of the chain CH3 CH3-C –CH -CH3 2,2-dimethylbutane CH3 • 2 3 4 CH3 CH3 CH3-CH –CH -CH3 2,3-dimethylbutane • 2 3 4

20. Write the structure for each of the following compounds • 4-ethyl-3,5-dimethylnonane (note the substituents are in alphabetical order separated by a dashed line) • 4-tert-butylheptane • (see your cheat sheet for tert structure)

21. 4-ethyl-3,5-dimethylnonane 4 1 9

22. 4-tert-butylheptane 1 2 3 4 5 6 7 CH3-CH2-CH2-CH-CH2-CH2- CH3 H3C-C-CH3 CH3

23. Reactions of Alkanes • Combustion reaction • Substitution reactions • Dehydration reactions • page1065

24. Cyclic Alkanes Add Cyclo to the number of carbons present

26. Naming cyclic structures with substituent • Give substituent the lowest number possible (can start with one this time) • If more than one substituent is present number in alphabetical order insuring that all substituents have the lowest possible number

28. Homework Read Page 1066 sample exercise 22.4 naming cyclic alkanes Do page 1100 #’s: 15, 17, 19, 20,

29. 22.2 Alkenes and alkynes • Hydrocarbons that contain carbon carbon double bonds. C2H4 C2H2

30. Rules for naming Alkenes • Root hydrocarbon chain ends in –ene methene Ethene Propene butene

31. In alkenes with more than three carbons, the location of the double bond is indicated by the lowest numbered carbon atom INVOLVED in the double bond. CH2= CHCH2CH3 1-butene CH3CH=CHCH3 2-butene

32. Double Bonding σ sigma bond π Pi bond

33. Isomers of Alkenes Cis: H on The same side of The molecule Trans: H on opposite sides of the molecule

35. Practice naming Find the longest chain and number it in the direction that gives the double bond the lowest number. Identify if the molecule is cis or trans 4-methyl-cis-2-hexene

36. Alkynes • Unsaturated hydrocarbons containing a carbon-carbon triple bond. • The simplest alkyne is C2H2 called acetylyne • In a triple bond there is one sigma bond and two pi bonds. • Replace the –ane ending –yne • Alkenes and alkynes can exist as ringed structures as well.

38. 2-methyl-3-heptyne Due to the triple bond there is no H to be cis or trans

39. Homework • Pg 1101 #’s : 21, 22, 23,24

40. Aromatic Hydrocarbons • A special class of cyclic unsaturated hydrocarbons. • The simplest is benzene C6H6

41. Resonance of Benzene

42. Nomenclature • If there is more than one substituent numbers are used to indicate position. 1,2,4-trichlorobenzene 2,4,6-trinitrotoluene (TNT)

43. FYI Toluene or Methylbenzene Common name IUPAC name

44. Some systems use prefixes for substituent position. • Ortho (o) for two adjacent substituent meta (m) two substituent with 1 carbon between them. para (p) two substituents opposite of each other When benzene is used as a substituent it is called a phenyl group.

45. 0-dichlorobenzene m-dichlorobenzene p-dichlorobenzene

46. o-bromochlorobenzene p-bromochlorobenzene Give substituents lowest number and place in alpha order.

47. Complex aromatics pg 1072 table22.3 Naphthalene   Anthracene  Phenanthrene

49. Homework • 25, 27(skip d) ,28, 29, 37, 38

50. 22.5 hydrocarbon Derivatives • Molecules that are fundamentally hydrocarbons (C&H) but have additional atoms or groups of atoms called functional groups • Functional Group: functional groups are specific groups of atoms with in molecules, that are responsible for the characteristics of those molecules