Functional Groups
Functional Groups
• An atom or group of atoms on a
molecule that always reacts in the
same manner.
The functional groups we will study
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Halocarbons
Alcohols
Ethers
Aldehydes
Ketones
Amines
Carboxylic acids
Esters
Amides
Halocarbons
•General form:
R
X
R is any chain or ring attached to the halogen
X is one of the halogens: Cl, F, Br, or I
Halocarbons
•Alkyl halide
•Halogen(s) attached to any aliphatic
compound.
Cl
H2C
Cl
CH
CH3
1,2-dichloropropane
Halocarbons
•Aryl halide
•A halogen attached to any aromatic
compound.
Cl
1,3-dichlorobenzene
(m-dichlorobenzene)
Cl
Alcohols
•General form:
R
O
H
O-H is a hydroxyl group
R is any chain or ring attached to the hydroxyl group
Naming alcohols
1. Count the carbon
atoms.
2. The name used is the
3
same as for alkanes.
 1 carbon: methane
3. Remove the –e
ending and add –ol.  1 carbon alcohol:
4. If necessary, identify
methanol
the carbon atom to
which the hydroxyl is
attached.
HC
O
H
You try it!
•Name this alcohol:
H3C
CH2 CH2
CH2 CH2 O
H
1-Pentanol
You try it!
•Name this alcohol:
H3C
CH2
CH
H O
CH2
CH3
3-Pentanol
Ethers
•General Form:
R
O
1
R
Note the central oxygen atom
Naming Ethers
Count the carbon atoms separately
on either side of the oxygen.
Use the branch name for each side,
listed alphabetically.
Add the word “ether” to complete the
name.
Naming Ethers
1 carbon on left:
2 carbons on right:
oxygen atom in between
H3C
methyl
O
CH2 CH3
ethyl
ethylmethyl ether
You try it!
•Name this ether:
H3C
CH2 O
CH2 CH2
CH3
ethylpropyl ether
Aldehydes
•General form:
•Contains a carbonyl group with
one hydrogen
O
carbonyl group
R
hydrogen
C
H
Naming Aldehydes
Count the carbon atoms.
Use the same name as you would for
an alkane with the same number of
carbons.
Remove the –e at the end and
replace it with –al.
hydrogen attached to carbonyl
carbonyl group
H3C
O
C
H
2 carbons
Ethane – e + -al =
ethanal
You try it!
Name this aldehyde
O
H
C CH2
CH2
CH3
butanal
Ketones
•General form:
O
carbonyl group
C
R
R
1
Chains or rings attached to either
side of the carbonyl
Naming ketones
Count the carbon atoms.
Use the name of the alkane with the
same number of carbons.
Number the carbon atoms so that
you identify the carbon to which the
carbonyl is attached.
Remove the –e and add –one.
Naming ketones
carbonyl group
O
carbonyl attached to
2nd carbon
C
H3C
Four carbons = butane
butane – e + one =
CH2
CH3
2-butanone
Is a number really necessary for this ketone?
You try!
•Name this ketone:
O
C
H3C
CH3
Is a number necessary for this ketone?
propanone
Amines
•Amines are simply ammonia
molecules in which one or more
hydrogen atoms have been substituted
with a branch or ring.
•General form:
Central nitrogen atom
R1 ,
R2
R,
and
are either
hydrogen atoms, branches, or
rings.
R
R
N
R
2
1
Naming Amines
Look for the central nitrogen.
Count the number of carbons on
each branch attached to the nitrogen.
List each branch by its name in
alphabetical order.
Add the word “amine” to the end of
the name.
Naming Amines
Central nitrogen
H3C
methyl group
H3C
H
N
CH2
ethylmethyl amine
ethyl group
Naming Amines
Central nitrogen
H3C
methyl group
N
ethyl group
CH2
CH3
CH3
ethyldimethyl amine
You Try!
•Name this amine:
H
N
H3C
CH2
CH3
CH2
diethyl amine
Carboxylic Acids
•General form:
carboxyl group
O
carbonyl group
C
R
hydroxyl group
O
H
When a carbonyl AND a hydroxyl are bonded
together, it is known as a carboxyl group.
Naming Carboxylic Acids
Identify the carboxyl group.
Count the carbon atoms.
Begin with the name of the alkane
that has the same number of
carbons.
Remove the –e and add –oic and the
word “acid” to the name.
If necessary, identify the carbon to
which the carboxyl group is
attached.
Naming Carboxylic Acids
carboxyl group
O
C
H
O
H
1 carbon atom
methane – e + oic acid = methanoic acid
You Try!
O
C
H3C
CH2
O
H
propanoic acid
Name this carboxylic acid
H3C
O
HC
CH3
C
O
H
2-methylpropanoic acid
Name this carboxylic acid
H3C
H3C
CH2
CH
CH
H3C
O
C
O
H
2,3-dimethylpentanoic acid
Noteworthy Carboxylic acids
O
H
C
methanoic acid
O
is called “formic acid”
H
Stinging ants use formic acid as a defense
mechanism.
O
H3C
C
ethanoic acid
is called “acetic acid”
O
H
This is the acid found in vinegar.
Esters
•General Form:
hydrogen is
replaced by a
chain or ring
O
R
C
Ester group
O
R
1
Naming Esters
Name the alkyl group
Identify the ester group and use the
acid name.
Remove the –ic and add –ate to the
end.
Naming Esters
ethanoate group
(acetate group)
O
C
methyl group
O
H3C
CH3
methyl ethanoate
or
methyl acetate
Naming Esters
•Name this ester:
propanoate group
ethyl group
O
CH2
H3C
C
O
CH3
CH2
ethyl propanoate
Amides
•General form:
O
R
C
H
N
H
The oxygen in the
carboxyl group is
replaced by a
nitrogen atom bonded
to other atoms.
Naming Amides
Count the carbons.
Use the name of the alkane with the
same number of carbons.
Replace the final –e with –amide.
Naming Amides
O
CH2
C
H
3 carbons = propane
N
H3C
propane – e + amide =
H
propanamide
You Try!
•Name this amide:
O
H3C
CH2
CH2
C
H
N
H
butanamide
A Noteworthy Amide:
O
CH CH
H3C
C
N
H
C
C
OH
CH CH
If you’ve ever had a headache, chances
are that you’ve taken this. This is
acetaminophen.
(Also labeled Tylenol.)