1

Haloalkanes, Alkenes, and Alkynes

Functional Groups

Haloalkanes

2

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

3

Some Types of Functional Groups

Haloalkane -F, -Cl, -Br CH3Cl

Alcohol -OH CH3OH

Ether -O- CH3-O-CH3

Aldehyde

KetoneC

O

CH3CH

O

C H

O

CH3CCH3

O

4

More Functional Groups

Carboxylic acid -COOH CH3COOH

Ester -COO- CH3COOCH3

Amine -NH2 CH3NH2

Amide -CONH2 CH3CONH2

5

Haloalkanes

An alkane in which one or more H atoms is replaced with a halogen (F, Cl, Br, or I)

CH3Br 1-bromomethane

Br (methyl bromide)

CH3CH2CHCH3 2-bromobutane

Cl

chlorocyclobutane

6

Learning Check HA1

Name the following:

Br

Cl

Cl

7

Solution HA1

Name the following:

bromocyclopentane

1,3-dichlorocyclohexane

Br

Cl

Cl

8

Substituents

List other attached atoms or group in alphabetical order

Br = bromo, Cl = chloro

Cl Br

CH3CHCH2CHCH2CH2CH3

4-bromo-2-chloroheptane

9

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

10

Solution HA2

The name of this compound is:

Cl CH3

CH3CH2CHCH2CHCH3

3) 4-chloro-2-methylhexane

11

Haloalkanes as Anesthetics

Halothane (Fluothane) F Cl

F C C Br

F HFluothane 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.

12

Ozone Layer

Ozone layer

Stratosphere

(10-30 miles

Above Earth)

13

Chlorofluorocarbons (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.

14

Chlorofuorocarbons and the Ozone Layer

In the stratosphere, the CFCs react with

the high-energy UV radiation from the sun

UV light

CF2Cl2 CF2Cl + Cl

Freon-12 free radical

15

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 atmosphere is an indicator of the disappearance of ozone.

16

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.

Explore chemistry! Explore life!!

17