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 number4. Name: location-alkan-ol: 1-pentanol5. 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 AlkenesThiol needs lowest carbon numberingName: location-alkene-location-thiolExample: 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