ABSTRACT
The carbonyl functional group consists of a carbon doubly bonded to an oxygen, and has the chemical structure C=O. Because of the electronegativity differences between the carbon and oxygen atoms in a carbonyl group, the C=O bond has a large dipole moment. There are some influences that cause the position of the C=O stretch band to move, such as changes in state and hydrogen bonding. A ketone is any molecule where both substituents on the carbonyl carbon are hydrocarbons. The atoms directly attached to the carbonyl carbon are called alpha carbons. Acetone, or dimethyl ketone, is the simplest ketone. For the acetone molecule, this vibration involves one methyl group moving toward the carbonyl carbon while the second methyl group moves away. The carbonyl group and the carbon and hydrogen attached to it are all in the same plane. One of the most important group wavenumbers for aldehydes is the C-H stretching vibration of the aldehydic hydrogen.
