4. Nomenclature of Alkanes Physical Properties Conformer Energy Baeyer Strain Theory Types of Isomers Reactions Naming Bicyclic Structures Nomenclature of Cyclics

5. Nomenclature of Alkanes

6. Homologous Series Structural Isomers IUPAC Rules Branches We will cover: Assigning Addresses Special Branches Nomenclature of Alkanes

7. Alkanes form the first homologous series that we study in organic chemistry. Nomenclature of Alkanes

8. Alkanes form the first homologous series that we study in organic chemistry. A homologous series is a collection of compounds that differ only by CH 2. Nomenclature of Alkanes

9. Alkanes form the first homologous series that we study in organic chemistry. A homologous series is a collection of compounds that differ only by CH 2. The alkanes are a homologous series with the formula, C n H 2n+2. Nomenclature of Alkanes

10. Alkanes form the first homologous series that we study in organic chemistry. A homologous series is a collection of compounds that differ only by CH 2. The alkanes are a homologous series with the formula, C n H 2n+2. What this means is all the compounds will have the same formula, C n H 2n+2, and when placed in order from smallest to largest will differ only by CH 2. Nomenclature of Alkanes

11. The smallest alkane is CH 4. (You should verify that it has the formula C n H 2n+2.) Nomenclature of Alkanes

12. The smallest alkane is CH 4. (You should verify that it has the formula C n H 2n+2.) The formula for the next structure would be … Nomenclature of Alkanes

13. The smallest alkane is CH 4. (You should verify that it has the formula C n H 2n+2.) The formula for the next structure would be … C 2 H 6, etc. Nomenclature of Alkanes

14. The smallest alkane is CH 4. (You should verify that it has the formula C n H 2n+2.) The formula for the next structure would be … C 2 H 6, etc. Let’s look at the first 20 compounds in the series and the names assigned to those compounds. Nomenclature of Alkanes

15. The smallest alkane is CH 4. (You should verify that it has the formula C n H 2n+2.) The formula for the next structure would be … C 2 H 6, etc. Let’s look at the first 20 compounds in the series and the names assigned to those compounds. What you need to learn to do is count to 20 in organic! Nomenclature of Alkanes

16. CH 4 methane CH 3 CH 3 ethane CH 3 CH 2 CH 3 propane CH 3 (CH 2 ) 2 CH 3 butane CH 3 (CH 2 ) 3 CH 3 pentane CH 3 (CH 2 ) 4 CH 3 hexane CH 3 (CH 2 ) 5 CH 3 heptane CH 3 (CH 2 ) 6 CH 3 octane CH 3 (CH 2 ) 7 CH 3 nonane CH 3 (CH 2 ) 8 CH 3 decane CH 3 (CH 2 ) 9 CH 3 undecane CH 3 (CH 2 ) 10 CH 3 dodecane CH 3 (CH 2 ) 11 CH 3 tridecane CH 3 (CH 2 ) 12 CH 3 tetradecane CH 3 (CH 2 ) 13 CH 3 pentadecane CH 3 (CH 2 ) 14 CH 3 hexadecane CH 3 (CH 2 ) 15 CH 3 heptadecane CH 3 (CH 2 ) 16 CH 3 octadecane CH 3 (CH 2 ) 17 CH 3 nonadecane CH 3 (CH 2 ) 18 CH 3 eicosane Nomenclature of Alkanes

17. CH 4 methane CH 3 CH 3 ethane CH 3 CH 2 CH 3 propane CH 3 (CH 2 ) 2 CH 3 butane CH 3 (CH 2 ) 3 CH 3 pentane CH 3 (CH 2 ) 4 CH 3 hexane CH 3 (CH 2 ) 5 CH 3 heptane CH 3 (CH 2 ) 6 CH 3 octane CH 3 (CH 2 ) 7 CH 3 nonane CH 3 (CH 2 ) 8 CH 3 decane CH 3 (CH 2 ) 9 CH 3 undecane CH 3 (CH 2 ) 10 CH 3 dodecane CH 3 (CH 2 ) 11 CH 3 tridecane CH 3 (CH 2 ) 12 CH 3 tetradecane CH 3 (CH 2 ) 13 CH 3 pentadecane CH 3 (CH 2 ) 14 CH 3 hexadecane CH 3 (CH 2 ) 15 CH 3 heptadecane CH 3 (CH 2 ) 16 CH 3 octadecane CH 3 (CH 2 ) 17 CH 3 nonadecane CH 3 (CH 2 ) 18 CH 3 eicosane Note, all the names end in “ane.” Nomenclature of Alkanes

18. CH 4 methane CH 3 CH 3 ethane CH 3 CH 2 CH 3 propane CH 3 (CH 2 ) 2 CH 3 butane CH 3 (CH 2 ) 3 CH 3 pentane CH 3 (CH 2 ) 4 CH 3 hexane CH 3 (CH 2 ) 5 CH 3 heptane CH 3 (CH 2 ) 6 CH 3 octane CH 3 (CH 2 ) 7 CH 3 nonane CH 3 (CH 2 ) 8 CH 3 decane CH 3 (CH 2 ) 9 CH 3 undecane CH 3 (CH 2 ) 10 CH 3 dodecane CH 3 (CH 2 ) 11 CH 3 tridecane CH 3 (CH 2 ) 12 CH 3 tetradecane CH 3 (CH 2 ) 13 CH 3 pentadecane CH 3 (CH 2 ) 14 CH 3 hexadecane CH 3 (CH 2 ) 15 CH 3 heptadecane CH 3 (CH 2 ) 16 CH 3 octadecane CH 3 (CH 2 ) 17 CH 3 nonadecane CH 3 (CH 2 ) 18 CH 3 eicosane Note, all the names end in “ane.” This is characteristic of alkanes. Nomenclature of Alkanes

19. Let’s consider some of the structural isomers of the alkanes. Nomenclature of Alkanes

20. Let’s consider some of the structural isomers of the alkanes. Structural isomers have the same formula, but different structures. Nomenclature of Alkanes

21. Let’s consider some of the structural isomers of the alkanes. Structural isomers have the same formula, but different structures. Does more than one structure exist for methane, CH 4 ? Nomenclature of Alkanes

22. Is there any other possible arrangement? Nomenclature of Alkanes CH H H H

23. Is there any other possible arrangement? NO! Nomenclature of Alkanes CH H H H

24. What about for ethane, C 2 H 6 ? Nomenclature of Alkanes

25. What about for ethane, C 2 H 6 ? Nomenclature of Alkanes CH H H C H H H

26. What about for ethane, C 2 H 6 ? If you are ever in doubt, use your models. Nomenclature of Alkanes CH H H C H H H

27. If you are ever in doubt, use your models. Now, look at propane, C 3 H 8 : Nomenclature of Alkanes

28. Now, look at propane, C 3 H 8 : Nomenclature of Alkanes CH H H C H H CH H H

29. Now, look at propane, C 3 H 8 : But, what about… Nomenclature of Alkanes CH H H C H H CH H H

30. Now, look at propane, C 3 H 8 : But, what about… Nomenclature of Alkanes C H H H C H C H H H H CH H H C H H CH H H

31. Now, look at propane, C 3 H 8 : But, what about? Are they the same? Nomenclature of Alkanes C H H H C H C H H H H CH H H C H H CH H H

32. If you have models, you should make the structure to prove to yourself that they indeed are the same. C H H H C H C H H H H CH H H C H H CH H H

33. If you have models, you should make the structure to prove to yourself that they indeed are the same. But how are you to tell without models? Nomenclature of Alkanes

34. If you have models, you should make the structure to prove to yourself that they indeed are the same. But how are you to tell without models? Here, let me show you. Nomenclature of Alkanes

35. If you have models, you should make the structure to prove to yourself that they indeed are the same. But how are you to tell without models? Let’s get rid of the hydrogens, leaving C skeletons. C - C - C H H H HHC - C - H H H H H HH C Nomenclature of Alkanes

36. If you have models, you should make the structure to prove to yourself that they indeed are the same. But how are you to tell without models? Let’s get rid of the hydrogens, leaving C skeletons. C - C - CC - C C Nomenclature of Alkanes

37. If you have models, you should make the structure to prove to yourself that they indeed are the same. But how are you to tell without models? Let’s get rid of the hydrogens, leaving C skeletons. C - C - CC - C C Now, can you draw a line connecting all the carbons without lifting your pen or retracing your steps? Nomenclature of Alkanes

38. If you have models, you should make the structure to prove to yourself that they indeed are the same. But how are you to tell without models? Here, let me show you. Let’s get rid of the hydrogens, leaving C skeletons. C - C - CC - C C These are both the same as “straight lines.” Nomenclature of Alkanes

39. If you have models, you should make the structure to prove to yourself that they indeed are the same. But how are you to tell without models? Here, let me show you. Let’s get rid of the hydrogens, leaving C skeletons. C - C - CC - C C These are both the same as “straight lines.” They are identical structures. Nomenclature of Alkanes

40. If you have models, you should make the structure to prove to yourself that they indeed are the same. But how are you to tell without models? Here, let me show you. Let’s get rid of the hydrogens, leaving C skeletons. C - C - CC - C C These are both the same as “straight lines.” They are identical structures. Doubtful? Make models. Nomenclature of Alkanes

41. A better way to teach and learn chemistry. End of Sample