GSCI 163

Lecture 13

Derivatives of hydrocarbons

Carbon can bond to one another and hydrogen, but they can also bond to other atoms and molecules. When they bond to other atoms and molecules besides hydrogen, they form derivatives molecules.

How do we classify the enormous number of compounds derived from hydrocarbons?

Functional group

The hydrocarbon structure function as a framework for the attachment of other atoms. These atoms are called heteroatoms (hetero = different). The heteroatoms give character to an organic molecule. Combined they form a functional group that behave as a unit.

Example:

ethane ethanol ethylamine

Alcohols

Hydroxyl groupAlcohols are soluble in water (why?)

Structure Scientific name

Common name

Melting point (C)

Boiling point(C)

Methanol Methyl alcohol -97 65

Ethanol Ethyl alcohol -115 78

2-Propanol Isopropyl alcohol -126 97

Phenols

Phenolic group

It is acidic because it readily loses an H+ in solution.

What happens with the electron left?Circles around the benzene ringFirst antiseptic for its anti-bacterial properties

(Joseph Lister, 1867)

Ethers

Ether group

Related to alcohols, but with the oxygen bonded to two carbons.

In contrast with alcohols they are not very soluble in water. Why? The absence of the hydroxyl group.

Most famous compound: diethyl etherThe first anesthetic. Characteristics: volatile, low solubility in water

Amine and alkaline

Amine group

Less soluble in water, lower boiling point as compared to alcohols.

Alkaline because they readily accepts hydrogen ion

Notable properties (low formula mass): offensive odorPutrescine Cadaverine

Carbonyl group

Carbon atom

A example of a ketone is Acetone, the fingernail polish remover.

double bonded to oxygen

Many have a particular fragrance; flowers for example owe their pleasant odor to the presence of simple aldehydes. One example is vanillin that give the pleasant vanilla taste.

Amide and carboxyl group

DEET - repellent Acetic acid - vinegar

Esters and their flavors and odors:

Building blocks of life

Amino acids is an organic compound that contains both an amino group and carboxyl group. There are over 20 known amino acids, 8 of which are essential to life.

Proteins are a long chain of amino acids bound together. The linkage process of each block is performed by the nucleic acids, which are themselves the made of amino and carboxyl groups.

Polymers

Blocks of monomers chained together:

Teflon, for example, looks like a chain of ethylanes where the hydrogen has been replaced by fluoride atoms:

Next class

• Final exam