Organic Chem Class #3

1. Organic Chem Class #3 OB: adding halogens into all three kinds of hydrocarbons. Take out Table R Why do Pirates Love Organic Chem? They really like table ARRRRGGHHHHH!

2. Draw these three molecules…. Butane propene 4-decyne

3. Draw these three molecules…. Butane propene 4-decyne -C-C-C-CΞC-C-C-C-C-C-

4. Now let’s look at the top of Table R The first “FUNCTIONAL GROUP” are the halogens. Functional groups are added to hydrocarbons to make them fancier, to make them more difficult, to make them smell better or worse, to give them a wide variety of properties. That’s the organic chem part. The first, and the simplest functional groups we’ll add in are the halogens. As you remember, group 17 contains the halogens: F, Cl, Br, and I When they are added to hydrocarbons we need to BOND them to the chains. Each halogen has 7 valence electrons. They all need to share ONE electron with something else (a carbon atom) to make a single bond. They all make only single bonds. Only single bonds. Only.

5. If we start with a simple ethane molecule we can substitute in a halogen for a hydrogen with a substitution reaction. We’re learning 2 new things at once. Ethane is a saturated hydrocarbon molecule (alkanes have as many H atoms as possible). We can’t ADD a halogen atom into ethane, but we can substitute in an atom for an H atom. This is a substitution reaction Ethane + Fluorine yields… + F2 F + HF Fluoro-ethane + hydrogen monofluoride

6. Let’s name these molecules now. Br F F F Cl F

7. Let’s name these molecules now. Br F F Bromo-ethane 1,2 di-fluoro-ethane F Cl F Chloro-ethane • 1,1 di-fluoro-ethane

8. The rules to naming these halo-carbons is easy. We’ll write them once, practice them lots, then you will just remember them because they are easy… Figure out the base chain name, that’s going to be the “LAST NAME” of the molecule. Double and Triple bonds “trump” fancy functional groups. They will decide the carbon atom counting. If no double or triple bonds, figure out which side we’ll count the carbons from, the fancy atoms (or groups) will decide which is the “short end to count from”. The halogens are named in ALPHABETICAL order first, numbers second. Like this… Cl Br F F

9. There is a 4 carbon butane base chain that these halogens are attached to… Bromine comes first, since B is before Cl or F. Br is on the 2nd carbon. Cl is second, it’s on the first carbon. Both of the F atoms are on the carbon atoms # 3 + 4 This would be 2-bromo, 1-chloro, 3,4-difluro-butane Cl Br F F

10. Cl ClCl F Br F Name this molecule… First, how many carbons in a row, and are they single bonds only? This is a nonane base chain. Which is carbon #1, thenwork out the first names

11. Cl ClCl F Br F Carbon #1 is the right side one, since the functional group closest to one end is closer to the right side carbon. Names go alphabetical, and numbered, so… 2-bromo, 5,6,7-tri-chloro, 1, 4-difluro-nonane

12. I I F Cl Name this funky thing. Base chain first always…

13. 13

14. I IF Cl Name the base chain first 1-octyne The base chain sets the carbon count. The chlorine comes first, so… 6-chloro, 7-fluoro, 8,8-di-iodo, 1-octyne

15. Let’s substitute in a Cl, over + over + over 4x + Cl2 Cl + HCl Methane and chlorine makes chloromethane and HCl Cl + HCl • + Cl2 Cl Cl • Chloromethane + chlorine makes dichloromethane + HCl

16. Do the next 2 substitution reactions, draw molecules, name the products Cl + Cl2 Cl

17. Cl Cl + Cl2 Cl + HCl Cl Cl Dichloromethane + chlorine yields trichloromethane + HCl Cl Cl Cl + Cl2 Cl Cl Cl Cl • Trichloromethane+ chlorine tetrachloromethane+ HCl

18. Name us

19. Trichloro, fluoro-methane • Tribromo, fluoro-methane