CH 320M/328M
Functional Groups
A functional group is a defined grouping of atoms in an organic molecule. A given functional group exhibits a
characteristic set of chemical properties, which are largely independent of the rest of the structure of the molecule in
which it is found. As a consequence, an understanding of the chemical behavior of the functional groups allows one
to predict the reactivity of a wide variety of organic molecules.
We will encounter numerous functional groups throughout our study of organic chemistry. A few of the more
important ones are listed in the table below (continued on the next page). At this stage, it is most important for you to
learn to recognize the general structures associated with these functional groups. In each case, a simple example is
provided as an illustration. (Note: A line indicates a single bond to carbon or hydrogen.)
Functional Group โ
General Structure Example
Functional Group โ
General Structure Example
C
Alkane
CH
3
CH
3
Ethane
C OH
Alcohol
CH
3
CH
2
OH
Ethanol
C C
Alkene
CH
2
=CH
2
Ethylene
C O C
Ether
CH
3
OCH
2
CH
3
Ethyl methyl ether
C
C
Alkyne
C
C
H
H
Acetylene
C SH
Thiol
CH
3
CH
2
SH
Ethanethiol
Aromatic Ring
(Arene) Benzene
C S C
Sulfide
CH
3
SCH
3
Dimethyl sulfide
C X
(X = F, Cl, Br, I)
Alkyl Halide
CH
3
CH
2
Br
Ethyl bromide
C N
Amine
CH
3
CH
2
NH
2
Ethylamine
