Tertiary is a term used in organic chemistry to classify various types of compounds (e. g. alcohols, alkyl halides, amines) or reactive intermediates (e. g. alkyl radicals, carbocations).
| Red highlighted central atoms in various groups of chemical compounds. Tertiary central atoms compared with primary, secondary and quaternary central atoms. | ||||
| primary | secondary | tertiary | quaternary | |
| Carbon atom in an alkane | 
|
|
|
|
| Alcohol | 
|
|
|
does not exist |
| Amine | 
|
|
|
|
| Amide | 
|
|
|
does not exist |
| Phosphine | 
|
|
|
|