Here are the main types of chemical nomenclature in a nutshell. Well, the post turned out to be a bit longer than I expected. So let’s say “chemical nomenclature in a coconutshell”.
- Compositional nomenclature
- Additive nomenclature
- Substitutive nomenclature
- Subtractive nomenclature
- Skeletal modification nomenclature
- Skeletal replacement
- ‘Homo’-type carbon insertion
- ‘Nor’-type subtraction
- ‘Cyclo’-type (ring addition)
- ‘Seco’-type (ring scission)
- Functional replacement nomenclature
- Conjunctive nomenclature
- Radicofunctional nomenclature
Compositional nomenclature
Compositional nomenclature can be used for both compounds and elementary substances.
Stoichiometric names reflect the empirical formulae or the molecular formulae. In case of compounds, these names are binary, i.e. any such name consists of two parts, (more) electropositive and (more) electronegative:
| empirical formula | Au | gold |
| empirical formula | NaCl | sodium chloride |
| empirical formula | SiO2 | silicon dioxide |
| molecular formula | O3 | trioxygen |
| molecular formula | CO2 | carbon dioxide |
Extended binary-type names still consist of two parts, positive and negative, at least one of which is a name of a heteropolyatomic ion. Typically these ions are given “acceptable non-systematic names”.
| KOH | potassium hydroxide |
| NH4NO3 | ammonium nitrate |
Additive nomenclature
Coordination-type additive names reflect the formulae of coordination entities. Any such name is a single word, where the ligands are listed first, followed by the name of the central atom:
| [UF6] | hexafluoridouranium |
| [Fe(NO)(OH2)5]2+ | pentaaquanitrosyliron(2+) |
| [Ag(SCN)4]3− | tetrakis(thiocyanato)argentate(3−) |
This method could be extended to dinuclear and polynuclear coordination entities with the help of geometrical and structural descriptors and bridging ligands.
| [OClO]• | μ-chlorido-dioxygen(•) |
| [W3O9] | cyclo-tri-μ-oxido-tris(dioxidotungsten) |
| [Cu4(μ4-S)] | μ4-sulfido-quadro-tetracopper(4Cu—Cu) |
Organic-type additive names are constructed in a number of ways:
- Hydrogen addition to unsaturated carbon—carbon bonds is expressed with a ‘hydro’ prefix (‘dihydro’, ‘tetrahydro’, etc.) to the parent name.
 | 1,2,3,4-tetrahydronaphthalene |
- Oxygen and halogen addition to unsaturated carbon—carbon bonds is expressed by binary names consisting of parent names followed by “oxide”, “chloride”, etc.
 | naphthalene 1,2-oxide |
 |
benzene hexachloride |
- Chalcogen addition to heteroatoms is expressed by binary names that consist of parent names followed by “oxide”, “sulfide”, etc.
 |
dibenzo[b,d]thiophene 5-oxide |
Substitutive nomenclature
Substitutive names are based on names of parent structures, parent hydrides or functional parents, modified with names of substituents that replace implicit hydrogen atoms.
A simple substitutive name is based on a single parent structure.
| CHBrCl2 | bromodichloromethane |
 | 4-amino-3-(4-chlorophenyl)butanoic acid |
 | 5,7-dichloro-2-methylquinolin-8-ol |
A multiplicative substitutive name is based on two or more identical parent structures linked by di- or polyvalent substituents:
 | 2,2′,2″-nitrilotriacetic acid |
 | 1,2′-methylenedinaphthalene |
Subtractive nomenclature
Subtractive names are constructed in a number of ways:
- With prefix ‘de’, followed by the name of a group or atom other than hydrogen, denotes replacement of that group or atom with hydrogen. Thus ‘demethyl’ means –CH3 → –H, ‘deamino’ –NH2 → –H, ‘decarboxy’ –COOH → –H, etc. As an exception, ‘deoxy’ indicates replacement of an –OH group by –H, i.e. a formal loss of an oxygen atom.
 | demethylmirtazapine |
 | deoxyadenosine |
- With ‘dehydro’ denoting the loss of a hydrogen atom; employed in pairs to indicate the unsaturation of a carbon—carbon bond, i.e. ‘didehydro’, ‘tetradehydro’, etc.
 | 1,2-didehydrobenzene |
- With ‘anhydro’, which refers to the formal loss of H2O from the parent molecule, often with new bond formation:
 | 1,6-anhydro-N-acetyl-β-D-muramic acid |
Skeletal modification nomenclature
Skeletal modification names are based on names of parent structures, parent hydrides or functional parents.
Skeletal replacement names are derived from the names of parent structures by replacing a skeletal atom. In organic structures, that means the replacement of a carbon atom (plus a number of implicit hydrogens) with a heteroatom (plus its implicit hydrogens). In heteroboranes, that means the replacement of boron atom(s) of a parent boron hydride with another element. This method is also known as ‘a’ nomenclature.
 | 3,6,9,12-tetraoxatetradecane-1,14-diol |
 | 1,3,5-trioxa-2,4,6-triboracyclohexane |
 | closo-1,12-dicarbadodecaborane(12) |
‘Homo’-type names contain the prefix ‘homo’ indicating the insertion of one carbon atom along with the implicit hydrogens into a parent structure.
 | homocysteine |
‘Nor’-type subtractive names contain the prefix ‘nor’ indicating the removal of one unsubstituted skeletal atom along with the implicit hydrogens from a parent structure.
 | 7-norcholest-4-en-3-one |
‘Cyclo’-type skeletal modification names contain the prefix ‘cyclo’ indicating an additional ring in a cyclic parent structure; ‘cyclo’ has to be preceded by the locants of the skeletal atoms that form a new bond.
 | 9β,19-cyclolanostane |
‘Seco’-type skeletal modification names contain the prefix ‘seco’ indicating ring cleavage in a cyclic parent structure; ‘seco’ has to be preceded by the locants of the skeletal atoms where the bond scission occurs.
 | 13-hydroxy-3-oxo-13,17-secoandrost-4-en-17-oic acid |
Functional replacement nomenclature
Functional replacement nomenclature uses the common names of oxoacids to create the names for their –OH or =O substitution derivatives.
 | trithiocarbonic acid carbonotrithioic acid |
 | sulfurothious O-acid |
 | sulfurothious S-acid |
Conjunctive nomenclature
Conjunctive names are constructed by joining together the names of its cyclic and acyclic parent structures:
 | benzeneacetic acid |
 | 1H-imidazole-4-ethanamine |
Radicofunctional nomenclature
Radicofunctional or functional class names are binary names consisting of the name of substituent followed by a functional class name.
| C2H5–OH | ethyl alcohol |
| H2C=CH–Cl | vinyl chloride |
| C2H5–C(O)–C2H5 | diethyl ketone |
 | methyl β-D-glucopyranoside |
 | benzoyl chloride |
 | benzoic anhydride |
 | benzyl benzoate |
 | sodium benzoate |
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