1. 2.1 UNSATURATED HYDROCARBONS
A hydrocarbon in which one or more carbon-carbon multiple bonds are present.
Carbon-carbon multiple bonds are chemically very reactive
Parts of organic compounds that are very reactive are called FUNCTIONAL GROUPS

2. FUNCTIONAL GROUPS C H C H O
If one or more hydrogens are replaced by a new bond C H
or a different atom a Functional Group is created. C H O

3. FUNCTIONAL GROUPS DEFINE A CLASS OF COMPOUND
Compounds in a class have similar physical properties
and chemical reactions.
ARE A REACTIVE SITE
Define the chemistry (reactions) for the group.

4. FUNCTIONAL GROUPS PROVIDE A BASE FOR NAMING COMPOUNDS
For instance, all ketones have the ending
-ONE in their names.
acetone
methyl ethyl ketone
cyclopropanone
CONSIST OF UP TO 5 ATOMS
Specific structure
Specific shape

5. KNOW YOUR FUNCTIONAL GROUPS
YOU SHOULD MEMORIZE THE NEXT TWO
SLIDES (see the handout ).
Know how to draw the Lewis Diagrams for these functional groups
YOU SHOULD ALSO MEMORIZE THE
TABLE OF COMMON ABBREVIATIONS
THAT IS PRESENTED IN THE SECTION
THAT FOLLOWS

6. COMMON FUNCTIONAL GROUPS
CLASS
FUNCTIONAL GROUP R R
ALKENES
double bond R C C R
R can be H C C
AROMATICS
Any compound which has a
benzene ring is “aromatic”
or “benzenoid”
benzene
ring
ALCOHOLS R O H
hydroxyl
ETHER
alkoxy
R cannot be H
H cannot be R
( R = any group of carbon and hydrogen atoms )
( Take special care where red arrows indicate )

7. FUNCTIONAL GROUPS ….. continued
CLASS
FUNCTIONAL GROUP
carboxyl R C O C O
CARBOXYLIC
ACIDS
R can be H O H O H
ester R C O C O
R can be H
ESTERS
R’ cannot be H O R’ O R R C H O
aldehyde
carbonyl
ALDEHYDES
KETONES
R cannot be H
H cannot be R
AMINES
amino
H can be R
AMIDES
amide
H can be R
R can be H

8. SPECIAL ABBREVIATIONS (condensed formulas)
GROUPS WITH
SPECIAL ABBREVIATIONS (condensed formulas)

9. SPECIAL ABBREVIATIONS
( continued )
-C6H5
benzene ring .. :
-CHO
aldehyde
( note H before O,
-C-OH is an alcohol) ..
(CO) or CO
carbonyl group :

10. SPECIAL ABBREVIATIONS
KNOW THESE - including electron pairs .. :
-COOH
carboxylic acid
-CO2H .. :
ester
-COOR ..
-CO2R .. ..
-NH2
amino group .. :
-CONH2
amide ..

11. MULTIPLE FUNCTIONAL GROUPS
MOLECULES WITH
MULTIPLE FUNCTIONAL GROUPS

12. IDENTIFYING FUNCTIONAL GROUPS
amine
alcohol
alkene
amide
ethers
Circle and name the functional groups.