1. Ch 12 Alcohols, Ether, Thiols
Naming

2. Functional Groups containing Oxygen
Functional Groups Molecule Class
-OH hydroxyl group Alcohols
-O- ether “ Ethers
C=O carbonyl “ Aldehydes, Ketones
carboxyl “ Carboxylic Acid

3. Molecules and Functional Groups containing oxygen
have a bent shape
are polar, soluble in water
form H-bonds

4. I. Alcohols
industrial ethanol production

5. Alcohol Naming -OH H3C -CH2- CH2 –CH- CH2-CH3 1 CH2-OH
H3C -CH2- CH2 –CH- CH2-CH3
1 CH2-OH
Find longest C-chain containing -OH group.
Name: drop the alkane ‘e’ replace with ‘-ol’
pentanol
3. Number: –OH is attached to lowest C number
Name: location-alkan-ol: 1-pentanol
4. Locate/list other substituents in front
2-ethyl-1-pentanol

6. Multiple Hydroxyls Include Carbon number add –di, -tri, -tetra….ol
1,2-propandiol
1,1-propandiol

7. Warm-up
A.) B.) OH A.) 3-methyl-2-pentanol B.) 4-methyl-2,3-pentandiol

8. Hydroxyls on alkenes/ynes
OH group location overides double/triple bond numbering
Use the functional group name: Hydroxyl
List alpha
2-Hydroxyl-4,4-dimethyl-trans-3-pentene

9. Phenol Benzene + Alcohol Group, must be called Phenol
Hydroxyl is always on C#1

10. Practice
2-methylphenol

11. Classification of Alcohols: Primary, secondary, tertiary
-OH attached to carbon with two other carbon and one H
-OH attached to carbon with one other carbon and two H
-OH attached to carbon with three other carbon and no H

12. Practice Draw the following alcohols in Kekule 1-Hexanol 3-Hexanol
1,2,3-Hexantriol
Name and classify as 1st, 2nd, 3rd alcohol
A B

13. Sulfur Instead of Oxygen
Same number of valence e-
Same number of bonds as oxygen
-SH is called a Sulfhydryl/Thiol group

14. Polarities EN of O: 3.5, S: 2.5, H: 2.1
Evaluate the polarities of the following bonds
O-H
C-O
C-S
S-H
C-H
C-S produces a ____ polar bond than C-O

15. Thiols -SH Longest carbon chain including thiol: lowest number
Name: location-alkanethiol 1-propanethiol
multiple: locations- alkanedithiol, -trithiol
1-propanethiol
2-methyl-1-propanethiol
2- propanethiol

16. -SH on complex Hydrocarbons
List alpha as thiol, the highest oxidized group determines numbering (O beats S) SH
2-hydroxyl- 3-methyl- 4-thiol-trans-2-pentene

17. Ethers -O-
Carbon chains on either side of ether are named alkyls according to length followed by ether- location not necessary!!!
List alphabetically or use di- if identical
diethyl ether
ethyl phenyl ether
ethyl methyl ether

18. 2. Alcohols, Ethers and Thiols in Nature

19. Alcohols in Nature Methanol: smallest alcohol in nature, toxic
Ethanol: byproduct of alcoholic fermentation (degradation of sugar in the absence of oxygen)
C6H12O6 → 2C2H5OH + 2CO2
Glucose Ethanol
CO2 causes fizzing, leavening bread…
Isopropanol: alcohol for disinfection, rubbing alcohol
Many flavors and aromas are alcohols: vanilla, thymol (thyme) eugenol (cloves), menthol

20. Thiols in Nature
Strong, borderline smells in nature are usually Thiols: onion, garlic, aged cheese: break down of amino acid Methionine

21. Ethers in Nature First anesthesia was done with diethyl ether
Inhalation anesthesia
Very volatile, and explosive
Many side effects
Not in use anymore
history of ether anesthesia

22. 3. Polarity of Alcohols, Thiols and Ethers

23. The Role of Oxygen
Oxygen has the second highest electronegativity of the PT: 3.5
Complete the table below: (EN: H: 2.1 and C: 2.5)
bond
C-H
O-H
C-O
∆EN
Polar/ nonpolar?

24. Polar Bonds = Polar Molecules!
In order to be a polar molecule it needs to have both:
Polar bonds and b. Polar symmetry
Polar Symmetries: Net Dipole
Dipole Bent Pyrimidal δ-
δ+ δ- δ+

25. Characteristics of Alcohols, Thiols and Ethers
Oxygen containing functional groups makes molecules polar!
(Sulfur is not very electronegative (2.5) so does not make hydrocarbons very polar – only structural asymetry)
Hydroxyl will change the Melting, Boiling Point and Solubility
Example:
Methane: gas
Methanol: liquid

26. 4. Characteristics of Alcohols, Thiols and Ethers
Melting/Boiling Point, Solubility in Water

27. Characteristics of Hydrocarbons
Non-polar
Have low Melting/Boiling points
Do not dissolve in water
Only attractive forces are Van-de-Waals

28. Characteristics of Alcohols (to some degree Thiols and Ether)
Are polar
Have a higher Melting/Boiling Point
Dissolve in water
Attractive forces include: H-bonds, Dipole Interactions and Van-de-Waals

29. 3 Intermolecular Attractions: how they influence MP/BP and solubility in water

30. 1. Hydrogen bonds – strongest intermolecular attraction
Intermolecular attraction of adjacent polar points (δ+, δ-) involving a Hydrogen
Indicated by a dotted line

31. 2. Dipole Interactions
attraction of adjacent polar points δ+, δ- not involving H

32. 3. Van-De-Waals
attractions caused by very weak EN differences (0.4 and lower)

33. Solubility in Water -A
Requires Hydrogen Bonds

34. HC chain length vs # of OH-groups
alcohol group polar
HC chain length vs # of OH-groups
Long HC chains reduce polarity/solubility in water
alkane chain: non-polar alcohol group: polar
not soluble so
forms H-bonds
soluble

35. Solubility of alcohols vs HC

36. Dissolving Molecules in H2O
Draw the molecule in VSEPR
Draw in all partial charges (δ+, δ+)
Associate 1 (one) H2O molecule per each δ+/- in the correct orientation (+ attracts -)
Draw in dotted lines
Example: Methanol

37. Type and number of intermolecular attractions between molecules determines MP/BP
Hydrocarbon
Ether
Alcohols
VdW +
Dipole -
H-Bond

38. Comparison of Alkanes, Ethers and Alcohols
Compound
Molar mass g/mole BP
Soluble in H2O
Butane
58 g/mol
0 Celcius no
Ethyl methyl ether
60 g/mol
8 Celcius
yes
Propanol
97 Celcius

39. Melting and Boiling Points

40. Fermentation
Fermentation

41. Warm-up 10 minute summary
How and why does alcohol affect the body and how does the body deal with it.
You may want to address the following….
which organs/tissues are affected by alcohol?
which organs/tissues are responsible for break down?
What are the long term affects of chronic alcohol abuse?