Archive:Introduction to Functional Groups
Introduction
Functional groups are groups of atoms within a molecule that affect its function. Some basic ones are listed below.
Hydroxyl Group
The hydroxyl group is formed by attaching a oxygen and a hydrogen atom to a molecule. Both the bond from the molecule to the oxygen and the bond from the oxygen to the hydrogen are single bonds; thus hydroxyl groups are usually denoted X-O-H. (where O is oxygen, H is hydrogen, and X is the molecule the hydroxyl group is attached to)
Carbonyl Group
The Carbonyl group is formed by attaching a oxygen to a carbon by a double bond, then attaching that same carbon atom to a molecule. A carbonyl group is denoted X-C=O
Carboxyl Group
The carboxyl group is formed by starting with a carbonyl group , then attaching a hydroxyl group to the same carbon atom in the carbonyl group. Finally, the carboxyl group is added to a molecule. Because carbon has four bonding sites, and three of them are taken up by the hydrogen and oxygen, the bond from the carbon to the molecule is a single bond. A carboxyl group is denoted X-COH=O