Chapter 11: Polymers

1. Chapter 11: Polymers

2. Section 11.1—Hydrocarbons

3. Organic Molecules & Hydrocarbons To understand Polymers – we MUST understand Organic Chemistry!! Organic Molecules– Contain carbon atoms bonded to other carbon atoms Hydrocarbons– Molecules composed of carbon and hydrogen only All carbon atoms need 4 bonds to be stable. They can be any combination of single, double, or triple. Hydrogen is used to fill in the remaining bonds!

4. Properties of hydrocarbons • Non-polar molecules-Non-soluble in water • Only IMF is London Dispersion Forces • The LARGER the hydrocarbon, the higher the IMF’s! So higher melting and boiling points too!

5. Trends in Carbon Chain IMF’s!

6. Alkanes Alkanes– Hydrocarbons containing only single bonds

7. Naming Alkanes • Count the longest continuous chain of carbon atoms. • Use the count as the prefix (see table) • Use “-ane” as the suffix • TIP – Mom Eats Peanut Butter…..Meth-, Eth-, Prop-, But- for the order!

8. Example #1 Example: Name the following molecule

9. Example #1 Example: Name the following molecule Find the longest chain of carbon atoms 4 A chain of 4 carbons = but- All single bonds = -ane butane

10. Let’s Practice #1 Draw a molecule of hexane

11. Let’s Practice #1 Draw a molecule of hexane Hex- = 6 carbons in a chain -ane = all single bonds Fill in with hydrogen atoms to give each carbon atom 4 bonds

12. Alkenes Alkenes– Hydrocarbons containing a double bond

13. Naming Alkenes • Count the longest chain of carbons starting with the end closest to the double bond. Use the carbon that gives the lowest count for the double bond. • Choose the appropriate prefix for this count • Count which carbon the double bond is on— • This number goes in front of the prefix and is separated with hyphen • Use the suffix “-ene”

14. Example #2 Example: Name the following molecule

15. Example #2 Example: Name the following molecule Find the longest chain of carbon atoms 4 A chain of 4 carbons = but-

16. Example #2 Example: Name the following molecule 2nd carbon 2nd carbon Find the longest chain of carbon atoms 4 A chain of 4 carbons = but- Count where double bond is from the side closest to it In this case, when you count from either side, the double bond begins on the 2nd carbon, so it doesn’t matter what side you count from 2-butene A double bond = -ene

17. Let’s Practice #2 Name the following molecule

18. Let’s Practice #2 Name the following molecule Find the longest chain of carbon atoms 7 A chain of 7 carbons = hept-

19. Let’s Practice #2 Name the following molecule 3rd carbon 4th carbon Find the longest chain of carbon atoms 7 A chain of 7 carbons = hept- Count where double bond is from the side closest to it From right, it’s on the 4th carbon. From left, it’s on the 3rd carbon. Pick the lower number 3-heptene A double bond = -ene

20. Alkynes Alkynes– Hydrocarbons containing a triple bond • All these NAMES! Here’s a Tip! • Single = ane • Double = ene • Triple = yne • A-E-Y notice that it is in alphabetical order!

21. Naming Alkynes • Count the longest chain of carbons starting with the end closest to the triple bond. Use the carbon that gives the lowest count for the triple bond. • Choose the appropriate prefix for this count • Count which carbon the triple bond is on— • This number goes in front of the prefix and is separated with hyphen • Use the suffix “-yne”

22. Let’s Practice #3 Draw a molecule of 1-butyne

23. Let’s Practice #3 Draw a molecule of 1-butyne But- = 4 carbons -yne = triple bond 1 = triple bond begins on the first carbon Fill in with hydrogen atoms so that each carbon has 4 bonds

24. Isomers Isomers– Molecules with the same chemical formula, but a different molecular structure Often, alkenes and alkynes can be isomers of each other. Both of these have the formula C3H4 but have different structures, as described by their different names. 1, 2—Propadiene 1-Propyne

25. Saturation Saturated hydrocarbon– All single bonds—the molecule is “saturated” with as many hydrogen atoms as it can hold Saturated molecules can pack together tighter and form more intermolecular connections. Saturated molecules therefore have higher melting and boiling points Unsaturated Saturated

26. Hydrocarbon Side-branches Hydrocarbon side-branches– Some molecules have groups of hydrocarbons branching off the main chain of carbons.

27. Naming hydrocarbon side-branches • Count the longest chain of carbon atoms (even if it’s not in a straight line) and choose the appropriate prefix for the chain. • Count to the carbon that the side-branch is on. Always count in a direction that gives the lowest number to the branch! This count will become a number in front of a prefix that represents the length of the side chain. (See the last slide for names) • Count the length of this side-chain and choose the appropriate prefix for the side chain. • Use an appropriate suffix to end the name • All together it will be: #-prefix prefix suffix

28. Example #3 Example: Name the following molecule

29. Example #3 6 carbons Example: Name the following molecule 7 carbons 4 carbons Find the longest chain of carbon atoms 7 A chain of 7 carbons = hept-

30. Example #3 Side-chain Example: Name the following molecule 7 carbons Find the longest chain of carbon atoms 7 A chain of 7 carbons = hept- Count where side-chain is from the end closest to it From the closest end, it’s on carbon #3 The side-chain has 1 carbon = meth- 3-methyl heptane A double bond = -ene

31. Side Chain Names and –ene and -yne • A side note – when naming double and triple bonds – the double and triple bond ALWAYS gets the lowest number. The side branch DOES NOT get the lowest number count.