Systematic Nomenclature
for Chemical Substances
Chemical Abstracts assigns
systematic CA Index Names to each substance mentioned in Chemical Abstracts
and to all additional substances from the original literature. These names are
based on the nomenclature rules of IUPAC (International Union
of Pure and Applied Chemists). To search for information
about a chemical substance, it is imperative that the searcher know the CA Index
Name.
The CA Index name is always
in inverted format:
| Heading
Parent- |
Substituent- |
Modification- |
Stereochemical
Descriptor |
The the heading
parent always appears first. The name of the heading parent is always
chosen to to correspond to the highest ranking functional group. The classes
of compounds are arranged in the following hierarchical sequence (in descending
order):
- Free radicals
- Cationic compounds
- Neutral coordination
compounds, inlcuding metallocenes
- Anionic compounds
- Acids in the order of
the central atom given by the sequence: C,S,Se,Te,O,P,As,Sb,Si,B
- Acid halides
- Amides
- Nitriles
- Aldehydes
- Ketones
- Alcohols and Phenols
- Hydroperoxides
- Amines
- Imines
- Compounds of N, P, As,
Sb, Bi, B, Si, Ge, Sn, Pb, O, S, Se, C
The substituents
follow in alphabetical order. The name modification
to the parent compound follows. Stereochemical descriptors
appear last, when necessary.
The inversion of systematic
Index Names in the Chemical Substance Index is extremely useful in the
search for derivatives or compounds related to certain substances. It is imperative
to identify the CA names when searching for chemical substances.