Functional Groups

Functional GroupsIB

ObjectivesObjectives• Concepts: • –Functional group, alkane, alkene, alkyne,

alcohol, carbonyl, aldehyde, ketone, carboxylic acid, ether, ester, amine, amide, halogenoalkane

• –Primary alcohol, secondary alcohol, tertiary alcohol, primary amine, secondary amine, tertiary amine,

• Skills: • –Draw and state names of the compounds

containing up to six carbon atoms with the following functional groups: aldehyde, ketone, carboxylic acid, alcohol, amide, amine, ester and halogenoalkane.

Functional GroupsFunctional Groups• As has already been indicated, alkanes are

relatively unreactive.

• For an organic molecule to be reactive it needs something additional.

• A site of reactivity in an organic molecule is called a functional group.

• C=C double is a functional group.

• Other functional groups contain elements other than C or H, notably O, N and Cl.

Functional GroupFunctional Group

• A functional group could be an atom or a group of atoms within a molecule that is responsible for its characteristic chemical reactions.

alkanesalkanes

• Only carbon and hydrogen

• All single bonds• Their names end with -

ane

CC H

H

HH

H

H

Ethane

alkenesalkenes

• Only carbon and hydrogen

• A carbon to carbon double bond

• Their names end with -ene

C C

H H

HH

Ethene

alkynesalkynes

• Only carbon and hydrogen

• A carbon to carbon triple bond

• Their names end with -yne

C CH H

Ethyne

alcoholsalcohols

• Only one oxygen• Has an O-H group• Can be classified as

1º/2º/3º according to position of O-H group on carbon skeleton

• They are named as alkanol

CC

H H

H

HH

HO

Ethanol

• Primary alcohol

CC

H H

H

HH

HO CC

H O

H

HH

HC

H

H

H

CC

H O

H

H3

H

HC

H

H

H

C

• Secondary alcohol

• Tertiary alcohol

aldehydesaldehydes

• Only one oxygen• Has a C=O group• C=O group is at the

end of the carbon chain, so is next door to a hydrogen atom

• They are named as alkanal

C C

H

H

O

HH

Ethanal

ketonesketones

• Only one oxygen• Has a C=O group• C=O group is not at

the end of carbon chain, so is next door to 2 carbons

• They are named as alkanone

C C

H

H

O

H

H

C

H

H

Propanone

estersesters• Has 2 oxygens• One oxygen is part of

a C=O bond, the other is next door, sandwiched between two carbons.

• They are named as Alkylalkanoate

C C

H

H

O

OH

C H

H

H

Methylethanoate

carboxylic acidscarboxylic acids• Has 2 oxygens• Has O-H and C=O

groups on the same carbon atom

• This -COOH group has to be at the end of a carbon chain.

• They are named as alkanoic acid

C C

H

H

O

OH

H

Ethanoic acid

etherether

• Has 1 oxygen• No O-H or C=O

group• The oxygen is

sandwiched between two carbon atoms

• Their names end with -ether

C C

H

H O

H

C H

H

H

H

H

Ethylmethylether

AminesAmines

• Contain Nitrogen

• Has an –NH2 group

• Can be classified as 1º/2º/3º according to the number of carbon atoms connected to the N

• They are named as alkyl amine

Ethylamine

CC

H H

H

HH

HN

H

AmideAmide

• Has NH2 and C=O groups on the same carbon atom

• They are named asalkanamide

C C

H

H

O

H

Ethanamide

HN

H

HaloalkanesHaloalkanes

• Have the general formula R-X where R is an alkyl group and X is a halogen

• They are named as haloalkanes

CC Cl

H

HH

H

H

Chloroethane

What family does it belong to? What family does it belong to?

C C

H H

HH

What family does it belong to? What family does it belong to?

C C

H

H

O

HH

What family does it belong to? What family does it belong to?

CC

H O

H

HH

HC

H

H

H

What family does it belong to? What family does it belong to?

H C O C H

H

H

H

H

What family does it belong to? What family does it belong to?

C C

H

H

O

OH

C H

H

H

What family does it belong to? What family does it belong to?

C C

H

H

O

H

H

C

H

H

What family does it belong to? What family does it belong to?

C C

H

C

O

OH

H

H

H

H

What family does it belong to? What family does it belong to?

CC

H

H

H

HO

CH H

H

C

H H

H