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