Transcript Haloalkanes and functional groups

Chapter 11
Haloalkanes, Alkenes, and Alkynes
Functional Groups
Haloalkanes
Timberlake LecturePLUS 1999
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Functional Groups
 Part of an organic molecule where



chemical reactions take place
Composed of an atom or group of atoms
Replace a H in the corresponding alkane
Provide a way to classify organic
compounds
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Some Types of Functional Groups
Haloalkane
Alcohol
-F, -Cl, -Br CH3Cl
-OH
CH3OH
Ether
-O-
CH3-O-CH3
O
O
Aldehyde
Ketone
C H
O
CH3CH
C
CH3CCH3
O
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More Functional Groups
Carboxylic acid -COOH
CH3COOH
Ester
-COO-
CH3COOCH3
Amine
-NH2
CH3NH2
Amide
-CONH2
CH3CONH2
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Haloalkanes
An alkane in which one or more H atoms is
replaced with a halogen (F, Cl, Br, or I)
CH3Br
1-bromomethane
(methyl bromide)
Br
CH3CH2CHCH3
2-bromobutane
Cl
chlorocyclobutane
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Learning Check HA1
Name the following:
Br
Cl
Cl
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Solution HA1
Name the following:
Br
bromocyclopentane
Cl
1,3-dichlorocyclohexane
Cl
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Substituents
List other attached atoms or group in
alphabetical order
Br = bromo, Cl = chloro
Cl
Br
CH3CHCH2CHCH2CH2CH3
4-bromo-2-chloroheptane
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Learning Check HA2
The name of this compound is:
Cl
CH3
CH3CH2CHCH2CHCH3
1)
2,4-dimethylhexane
2)
3-chloro-5-methylhexane
3)
4-chloro-2-methylhexane
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Solution HA2
The name of this compound is:
Cl
CH3
CH3CH2CHCH2CHCH3
3) 4-chloro-2-methylhexane
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Haloalkanes as Anesthetics
Halothane (Fluothane)
F Cl
F
C
C
Br
F
H
Fluothane is a haloalkane that is widely used
as an anesthetic, which is a compound that
decreases the ability of the nerve cells to
conduct pain.
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Ozone Layer
Ozone layer
Stratosphere
(10-30 miles
Above Earth)
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Chlorofuorocarbons (CFCs and
the Ozone Layer
ozone O3 layer absorbs most of the
sun’s harmful radiation.
CFCs - chlorofluorocarbons - are
depleting that ozone layer.
CFCs are used as Freons in
refrigeration,
air conditioning, and foam insulation.
Their use in spray cans is no longer
allowed.
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Chlorofuorocarbons and the
Ozone Layer
In the stratosphere, the CFCs react with
the high-energy UV radiation from the sun
CF2Cl2
Freon-12
UV light
CF2Cl + Cl
free radical
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Chlorofuorocarbons and the
Ozone Layer
To become stable, the Cl acquires an electron
from ozone O3 and produces ClO.
Cl
+
O3
ClO + O2
The presence of ClO in the atomosphere is an
indicator of the disappearance of ozone.
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Impact of Loss of Ozone Layer
According to the National Academy of
Sciences, each 1% loss of ozone increases
by 2% the amount of UV radiation reaching
the earth. More UV radiation means more
skin cancer and cataracts in humans, more
intense photochemical smog, and lower crop
yields.
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