Ch 12 Alcohols, Ether, Thiols
Naming and Properties
Molecules and Functional Groups
containing oxygen and sulfur
• have a bent shape (like water)
• are polar - therefore soluble in water
• form H-bonds
Alcohol Naming -OH
5
4
3
2
H3C -CH2- CH2 –CH- CH2-CH3
1 CH2-OH
1.Find longest C-chain containing -OH group.
2.Name: drop the ‘e’ replace with ‘-ol’ (pentanol)
3. Number: –OH is attached to lowest C number
4. Name: location-alkan-ol: 1-pentanol
5. Locate/list other substituents in front
2-ethyl-1-pentanol
Multiple Hydroxyls (-OH)
• Include Carbon number
• add –di, -tri, -tetra….ol
1,2-propandiol
1,1-propandiol
Hydroxyls on alkenes/ynes
• OH group location overrules double/triple bond
• Add at the end of the molecule
• Cis-2-butene-1,4-diol
Classification of Alcohols:
Primary, Secondary, Tertiary
-OH attached to
carbon with one other
carbon and two H
-OH attached to
carbon with two
other carbon and
one H
-OH attached to carbon
with three other carbon
and no H
Thiols -SH
• Number carbon chain, thiol is lowest number
• Name: location-alkanethiol (1-propanethiol)
• multiple: locations- alkanedithiol, -trithiol
1-propanethiol
2-methyl-1-propanethiol
2- propanethiol
Thiols on Alkenes
Thiol needs lowest carbon numbering
Name: location-alkene-location-thiol
Example: 2-propene-1-thiol
Ether Naming C-O-C
• Carbon chains on either side of ether are named
alkyls according to length followed by ether
• List alphabetically or use di-, tri- if identical
diethyl ether
ethyl phenyl ether
ethyl methyl ether
Properties of Alcohols
alkane chain non-polar
alcohol group polar
forms H-bonds
Solubility
• With increasing alkane chain, solubility in water
decreases
• Balance between length of HC and number of –OH
• Tip – with 4 or fewer C it is soluble, 5 or more, not
very soluble
Solubility
• Ethers are more soluble than alkanes, but not
as soluble as alcohols
• Phenols are soluble in water because of –OH
Comparison of MP and BP
• The more polar the molecule the higher the
Melting Point and Boiling Point
Homework
• Pg 390 12.2 – 12.12 even
• Pg 394 12.14 and 12.16