2. Organic Naming Rules AP Chemistry 439 For complete Rules go to: http://www.acdlabs.com/iupac/nomenclature/

3. Organic Compounds Consist of mainly four elements C arbon H ydrogen O xygen N itrogen

4. Why Do We Need a Separate Set of Rules? Examine some typical organic compounds CH 4 C 2 H 6 Name these using typical covalent rules Carbon tetrahydride Dicarbon hexahydride

5. So? That wasn’t so bad, right? How about these: C 4 H 10 C 5 H 12 See my point? Tetracarbon decahydride Pentacarbon ??? hydride

6. Isomers If that’s not enough, how about this one: C H H C H H C H H C H H HH Formula? C 4 H 10 C H H C H HC H H CH H H H Formula? C 4 H 10 Different Structure Same Formula

7. Overall Problems Memorizing too many prefixes for large numbers Different chemicals having the same formulas Keep in mind that thus far we’ve only dealt with TWO different elements!

8. So what to do? Number of hydrogens is going to be the same, regardless of isomerism C H H C H H C H H C H H HHC H H C H H C H H C HH C H H HH C H H C HH C H H C HH C H H H H C H H C 5 H 12

9. Solution Since number of hydrogens don’t change with isomerism, why bother naming them? Name the molecule simply based on number of CARBONS We can always add prefixes or suffixes later for differentiation

10. Name based on number of Carbons 1 2 3 4 5 6 7 8 9 10 Methane Ethane Propane Butane Pentane Hexane Heptane Octane Nonane Decane

11. Did that Really Help? C H H C H H HHC H H HH Carbon tetrahydride becomes:Methane Dicarbon hexahydride becomes: Ethane C H H C H H C H H C H H HHC H H C H H C H H C H H CH 4 C2H6C2H6 Octacarbon ???hydride becomes: Octane C 8 H 18

12. Branches Straight-chain alkanes (Just C & H with single bonds) are now easy C H H C H H C H H C H H HH C 4 H 10 Butane But how do we deal with branches? C H H C H HC H H CH H H H C 4 H 10 ????

13. Rules pt. 2 Identify the longest unbranched chain of carbons Name it as normal Identify the branch Name it but give it a “–yl” suffix Put the names of all branches first, then put name of longest chain

14. Example C H H C H HC H H CH H H H Longest unbranched chain of carbons is three long propane Branch is one long methyl Methyl Propane

15. Practice C H H C H H C H HC H H H C H HH Methyl butane HHHHH C H C H CHC H C H H CHH C H HH Ethyl pentane

16. One More Practice CCC C C CCC C C It doesn’t matter which way you go! (Provided you correctly pick the longest unbranched chain) Methyl Butane

17. Be Careful H CCCCC HHHH HHHH HH C H H C H H H Hexane This is your longest uninterrupted chain Methyl Methyl Hexane

18. A Small Wrinkle H CCCCC HHHH HHHH HH C H H H H CCCCC HHHH HHHH HH C H H H Methyl Pentane These are different molecules, though!!!

19. So Now What? Since two different molecules can’t have the same name, we must differentiate If we look closely, though, the only difference between them is the position of the methyl group

20. Positioning H CCCCC HHHH HHHH HH C H H H H CCCCC HHHH HHHH HH C H H H Here the methyl group is on the second carbon from the end Here the methyl group is on the third carbon from the end Methyl Pentane So… 2-3-

21. Rules pt. 3 Identify the longest unbranched chain of carbons Name it as normal Identify the branch Name it but give it a “–yl” suffix Put the names of all branches first, then put name of longest chain Put the number of the carbon the branch is on (start numbering from the closest single end)

22. Practice H CCCCC HHHH HHHH HH C H H H C H H C H H H CCCCC HHHH HHHH HH C H H H CC HH HH C H H 2-methyl heptane 4-methyl octane H CCCC HHH HHH H C H H H C H H H C H H 2-methyl hexane

23. Multiple Branches So far we’ve only had one branch What happens when there are multple branches? Just add a prefix to indicate the number of a particular type of branch

24. Practice H CCCCC HHH HHHH HH C H H H C H H C H H C H H H heptane methyl 2- 2-methyl, 2-methyl heptane Sounds redundant 2,2 dimethyl heptane

25. More Practice C H H H H CCCCC HHH HHHH HH CC HH HH C H H C H H H CCC C C HHH HHH HH C H H H H C H H C H H H C H H H 2, 6-dimethyl octane 3 ethyl-2,4- dimethyl pentane

26. Is your arm sore yet? Are you sick to death of writing all those carbons? Even worse, are you sick of writing all those Hydrogens? How about this…

27. Shorthand notation C H H C H H C H H C H H HH Keep in mind that we have been ignoring the hydrogens for a long time. Our names have been based entirely on the positioning of the carbons. So lets now ignore the hydrogens completely!

28. Is it that easy? H CCCCC HHHH HHHH HH C H H H C H H C H H C H H H H CCCCC HHH HHHH HH CC HH HH C H H C H H H

29. One More CCC CC HH H HH H H H C H H H H C H H C H H H C H H H C H H Shorthand notation? Name? 3-ethyl-2,4 dimethyl hexane

30. So is that it? Not even close!! There are literally millions of different organic compounds. What else can we do to make things more complicated?

31. Rings Thus far we have dealt with chains that are straight or branched. If hydrocarbons are long enough, one end can wrap around and link up with itself! We call these cyclic hydrocarbons.

32. Cyclic Hydrocarbons Name the molecule as normal Add the prefix cyclo- to the front of the name of the longest chain Start numbering from the most “important” branch in the ring

33. Examples Cyclohexane Cyclooctane

34. More Examples Methyl cyclopentane 1,2 dimethyl cyclohexane

35. Try These 1 ethyl, 3 methyl cyclobutane 3 methyl, 1 propyl cylclohexane

36. Multiple Bonds So far, even with the cyclic structures we have dealt only with single bonds Carbon can make multiple bonds to another carbon This changes the name Why?

37. Examine Structures C H H C H H HH C2H6C2H6 Ethane- notice that each carbon has four bonds What will happen to the structure if we double bond the two carbons? C H C H HH C2H4C2H4 Each carbon still has four bonds BUT now the hydrogens have changed!!

38. Naming molecules with multiple bonds Name the molecule as normal Change the suffix of the longest chain name Double bonds = ene Triple bonds = yne Use numbering and prefixes for positioning and multiple multiple bonds.

39. So…. C H H C H H HHC H C H HH CCHH C2H6C2H6 C2H4C2H4 C2H2C2H2 ethane ethene ethyne

40. Practice CCCC HH HHH H H C H H H C H H 3 methyl-1-pentene H H CCCCC HHHH HHH H C H H C H H 2-heptene H H CC H H H C H C H H 1-butene

41. How about in Shorthand? Notice the two lines means the double bond is there! 2 pentene

42. Practice! Methyl propene 2,4-dimethyl-2-pentene 3-ethyl-2,4,4-trimethyl-1-pentene

43. Tough Ones 2 methyl 1,3 butadiene 1,2 dimethyl-1,4 cyclohexadiene

44. Triples? 3, 3-dimethyl-1-butyne 1,4 cyclohexadiyne

45. So that’s it, right? Not even close, bud. All this….all this was just for two elements, carbon and hydrogen!! We haven’t even dealt with any of the others, yet.

46. Wait!! Don’t jump!! Get off that bridge. It’s not that bad provided we arrange things in an organized fashion!

47. Functional Groups Nature has done us a favor. There are many common groups that we can organized or file into different categories. Then we can name them based on these categories.

48. Functional Groups A group of atoms that, when added to a hydrocarbon chain, alter the chemical properties of the chain. Just a few different functional groups to know…

49. Functional Groups Halogens Alcohols Ethers Aldehydes Ketones Carboxylic Acids Esters Amines R-F, R-Cl, R-Br, R-I R-OH R-O-R R-COH R-CO-R R-COOH R-COO-R R-NH 2

50. Halides Fluorides, Chlorides, Bromides, and Iodides Simply name the molecule as normal but add the prefix Fluoro, Chloro, Bromo, or Iodo as necessary

51. Halides Cl 2, 3 dichlorohexane I I 3, 3 diiodo-1-pentene

52. Alcohols R-OH Name like normal except add an –ol suffix

53. Alcohols OH C H H C H H H 2 propanol ethanol 1cyclobutenol

54. Ethers R-O-R Name two “R” groups with –yl endings End name in ether

55. Ethers O Dimethyl ether O Ethyl methyl ether

56. Aldehyde R-COH This is a carbon to oxygen double bond with a hydrogen at the end. Name as normal except use a “-al” suffix

57. Aldehydes C H H C H H C H H CHH O butanal C H H C Cl C H H CH O C H H H 3,3 dichloropentanal

58. Ketones R-CO-R This is a carbon to oxygen double bond but in the center of a hydrocarbon chain rather than the end Name as normal but give it a “-one” suffix

59. Ketones propanone 2 hexanone C H H C H H CHH O C H H C H H C H H C O C H H HC H H H

60. Carboxylic Acids R-COOH or R-CO 2 H This is a carbon to oxygn double bond with the same carbon single-bonded to an OH group. Name as normal except give it the suffix “-anoic acid”. HC 2 H 3 O 2

61. Carboxylic Acids C H H C H H C H H CHOH O Butanoic acid C H H C H H FC O HO 3-Fluoropropanoic acid

62. Esters R-COO-R This is a carbon to oxygen double bond with a carbon to oxygen single bonded to another single bonded carbon Name by given secondary branch “-yl” suffix and main branch “-anoate” suffix.

63. Esters C H H C H H C H H C O C H H HC H H HO Secondary Branch Main Branch methyl pentanoate Methyl Pentanoate

64. Esters C H H HC H H C O C H H O C H H H C H H C H H Butyl propanoate C H H HO H H C O C H H C C H H H C H H C H H Methyl hexanoate

65. Amines R-NH 2 Name the “R” group or groups with “-yl” endings Add the word “amine”

66. Amines C H H N H H H Methyl amine C H H N C H H H H H Dimethyl amine

67. Summary Cl R Halide OH R Alcohol R RO Ether H RC Aldehyde O R RC Ketone O OH RC Carboxylic Acid O O RC Ester O R NH 2 R Amine

68. Alkanes Alkenes Alkynes Halides Alcohols Ethers Aldehydes Ketones Carboxylic Acids Esters Amines Summary -“-ane” =“-ene” “-yne” R-X“-o” R-OH“-ol” R-O-R“-yl ether” R-COH“-al” R-CO-R“-one” R-COOH“-anoic acid” R-COO-R“-yl” “-anoate” R-NH 2 “-yl amine”

69. Can You Do This? YES! It takes: Memorization Practice And, oh yes… Practice!