Functional Groups
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Transcript Functional Groups
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
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(Also labeled Tylenol.)