Functional group
- Set of atoms and bonds characterized by a predictable chemical behavior
Formal Charge (FC)
- Used to identify lone pairs of heteroatoms in line structures
- FC = number of valence electrons – (number of nonbonding electrons + number of bonds)
Structures of functional groups of heteroatoms
Halides
- Alcohol = R-OH
- Ether = R-OR'
- Ketone = R-carbonyl-R'
- Aldehyde = R-carbonyl-H
- Acetal = carbon bonded to OR, OR', R'', R'''
- Carboxylic acid = R-carboxyl
- Anhydride = R-carbonyl-O-carbonyl-R'
- Ester = R-carbonyl-OR'
- Amine = nitrogen bonded to R, R', R''
- Imine = carbon double-bonded to NR
- Thiol = R-SH
- Sulfide = R-SR'
Halides and oxygen
- Acyl halide = R-carbonyl-X
Oxygen and nitrogen
- Amide = carbonyl bonded to an amine
Oxygen and sulfur
- Sulfone = sulfur double-bonded to two oxygens