Carbon Chemistry

 

Carbon has a valence of 4 which makes it capable of entering into 4 covalent bonds.

 

This situation allows carbon to form many different chemical compounds. The following are variations in which carbon may form different chemical compounds:

 

1). Length of the carbon skeleton may differ ( C-C, C-C-C, C-C-C-C-C, etc.).

 

2). Branching of the carbon skeleton C-C-C-C-C-C-C-C-C

C

 

3). The number of double bonds may differ ( C=C-C-C, C=C=C-C ).

 

4). The molecular structure may be in a ring form.

 

 

Chemical compounds with the same molecular formula but different structural formulas is called an isomer.

 

There are 3 types of isomers:

 

a). Structural: These isomers differ from others due to the differing covalent arrangements of the atoms.

 

b). Geometric: These isomers contain the same covalent arrangement but different spatial arrangements. The double bonds make the molecule rigid which prevents atomic rotation.

 

c). Optical: These isomers are mirror images of one another. There are right and left handed versions of these compounds. The asymmetrical carbon, this is the carbon that is attached to 4 different groups, revolves causing the isomer to occur. The left handed isomer usually functions in nature, while the right has no use or can cause problems in the organism using it.

 

Functional Groups: These are certain groups of atoms attached to the carbon skeleton. This area is usually on the end of the molecule. This region is the focus of most chemical reactions. These groups change the activity and function of the molecule they are added to.

 

1. Hydroxyl R- OH makes molecule polar and produces an alcohol.

 

2. Carbonyl R=O produces compounds known as ketones and aldehydes

 

3. Carboxyl R=O and OH forms organic acids (carboxylic acids: formic, acetic, etc.).

 

4. Amino R- N + 1 charge, usually basic, acts as a good buffer.

 

5. Sulfhydral R- S-H thiols, stabilizes protein molecular structures.

 

6. Phosphate R- O- P- O plus 2 more Oxygens attached to the P. energy storage that can be passed on from one molecule to another by the transfer of the group.

Alkanes: Hydrocarbons containing 1 single covalent bond. Examples: Methane (CH₄), ethane (C₂H₆), propane, butane, pentane, hexane, and heptane. Their boiling point increases as the molecules get larger.

Alkenes: Carbons are connected with double bonds. Example ethylene (C₂H₄), propene (C₃H₆). Rotation does not occur around the double bond.

Alkynes: Triple bonds connecting the carbons. Acetylene (C₂H₂).