Chemistry - A Molecular Science

Chapter 13 Organic Chemistry

Functional groups are groups of atoms that are reactive. •

Alcohols contain the hydroxyl group. They

are weaker acids and stronger bases than water.

The names of all alcohols end in -

ol. The position of the hydroxyl group in the longest

continuous chain is indicated by a prefix. Thus,

3-hexanol is a six-carbon chain with a hydroxyl

group attached to the third carbon.

(^) •
Carbonyl groups are C=O groups. Their reactivi
ty can be understood in terms of a resonance
form containing a carbocation, which is a very strong Lewis acid.
(^) •
Carboxylic acids contain a carbonyl and a
hydroxyl group bonded to one another. They are
Brønsted acids, but they also have the carbonyl functionality described above. The names of carboxylic acids all end in -
oic
acid

. Thus, octanoic acid is C

H 7

COOH. Fatty acids are 15

carboxylic acids with long chains.

(^) •
Amines are organic derivatives of ammonia. Like ammonia, they are Lewis bases. Molecules containing both carboxylic acids and amines are known as
amino acids
.
(^) •
Esters are the product of the reaction of a
carboxylic acid and an alcohol. In the reaction
mechanism, the lone pair of
the alcohol attacks the carbocat
ion on the acid, a proton is
transferred from the alcohol to the carboxylic acid, and the resulting water molecule is lost.
(^) •
Amides are the product of the reaction of a carboxylic acid or an ester with an amine. The reaction mechanism for the reaction between an amine and an ester is identical to the formation of the ester from a carboxylic acid and an alcohol, except that the amine is the Lewis base that attacks the carbocat
ion of the ester. After proton tr
ansfer, it is an alcohol that
leaves the molecule. Polymers
are large molecules formed by bonding smaller units, called monomers,
together in long chains. Alkene polymers are called addition polymers. They can be formed by the reaction of the alkene with
a small amount of a hydrohalic acid. Common
synthetic polymers include polyethylene, PV
C, and polystyrene. Condensation polymers
result when molecules containing two functional groups react. Thus, a polyester is prepared by reacting a dicarboxylic acid w
ith a diol. Nylons are polyamides made by
reacting a diester with a diamine. Polypeptides are polyamides made by reacting amino acids. Proteins are large polypeptides. Three-dimensional structures, such as the protein

• α

helix and the DNA double helix, are the result of hydrogen bonding and are vital to the function of biomolecules.

OH

alcohol

R

O C

O C

carbonyl

R

C

O

O

H

carboxylic acid

N

R

RR

NH

C

O

O

RH

amine

amino acid

R

C

O

O

R

ester

R

C

NH

O

R

amide

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State

University