Wikipedia:Naming conventions (chemistry)
From Free net encyclopedia
Template:Wikipedia subcat guideline Template:Main
Contents |
General rule
From Wikipedia:Naming conventions:
- "Generally, article naming should give priority to what the majority of English speakers would most easily recognize, with a reasonable minimum of ambiguity, while at the same time making linking to those articles easy and second nature."
IUPAC preferred name vs. Systematic name
IUPAC recommends Template:Ref the use of non-systematic names for some organic compounds, and these recommendations should be followed in article titles. Examples:
| Acetic acid | not | Ethanoic acid |
| Toluene | not | Methylbenzene |
| Lysine | not | 2,6-Diaminohexanoic acid |
Element names
Traditionally, the names of three elements have been spelt differently in US and British English. With the onset of computer searching of databases it became necessary to standardize these spellings as follows:Template:Ref
| Aluminium | not | Aluminum |
| Sulfur | not | Sulphur |
| Caesium | not | Cesium |
These international standard spellings should be used in all chemistry-related articles on English Wikipedia, even if they conflict with the other national spelling varieties used in the article.
Use of Stock nomenclature
Stock nomenclature for inorganic compounds is based on the indication of the oxidation number (as a roman numeral, in parentheses) of each of the major elements in the compound, e.g. iron(III) chloride. It is widely, if sometimes incorrectly, used on Wikipedia for the titles of articles about inorganic compounds. It is not obligatory, as there are other acceptable methods for naming these compounds, but it is often preferred as the most common non-ambiguous name for a substance. The following guidelines are based on current WikiBestPractice:
- Only the cationic element (i.e. the element whose name appears unchanged in the compound name) is assigned its oxidation number. Except in rare cases (none at present), we do not assign the oxidation number in the anion: hence potassium permanganate not potassium manganate(VII), sodium hypochlorite not sodium chlorate(I).
- There is no space between the end of the element name and the opening parenthesis: hence silver(I) fluoride not silver (I) fluoride. Note that this is an exception to the usual English style for parentheses.
- It is not necessary to specify the oxidation number when there is no possibility of ambiguity in the compound title: hence sodium chloride not sodium(I) chloride.
- Stock nomenclature should only be used for ionic compounds. Compounds with a substantial degree of covalency should be named by stoichiometric nomenclature: hence titanium tetrachloride not titanium(IV) chloride.
- Stock nomenclature should not be used for compounds with mixed or non-integral oxidation numbers: hence triiron tetraoxide not iron(II,III) oxide (in fact, this article is difficult to name and, as an exception, redirects to magnetite).
Drug-related articles
See also WikiProject Drugs
Where a compound has a WHO International Nonproprietary Name (INN), this should be used as the article title.
Prefixes
For technical reasons, it is not recommended to use non-numerical prefixes in article titles. This includes:
| Positional identifiers | ortho-, meta-, para-, α-, β-, γ- |
| Stereochemical identifiers | cis-, trans-, (E)-, (Z)- |
| Chiral identifiers | (R)-, (S)-, D-, L-, (+)-, (−)- |
Note that iso in such compounds as isopropanol is not only permitted but recommended. No hyphen is used in these cases. sec- and tert- are hyphenated and non-capitalized, and should be avoided if possible on Wikipedia.
When the chosen article title starts with a number, the first letter of the compound name should be capitalized: hence 1,1,1-Trichloroethane not 1,1,1-trichloroethane. A redirect from the uncapitalized version should be created to simplify linking from other articles. See also Capitalization below.
Redirects
- From Wikipedia:Deletion policy: "Don't worry, redirects are cheap."
Redirects should be created for:
- Alternative names for the compound, including acronyms where appropriate;
- Alternative capitalizations, where there is a numerical prefix in the article title.
Exceptions
Even with the best will in the world, no set of guidelines can cover every case. Some articles on Wikipedia have non-standard titles through consensus that this is the most commonly used name (in scientific circumstances) for the compound concerned, whatever IUPAC or the other rules suggest. For example:
- Ethylene oxide not oxirane
- Phosphine not phosphane (and for substituted phosphines, arsine and stibine)
- Wilkinson's catalyst not chlorotris(triphenylphosphane)rhodium
- Vaska's complex not carbonylchlorobis(triphenylphosphane)iridium
Please do not get into revert wars over the naming of an article: the best place for discussion is on the article's talk page or (failing that) at Wikipedia talk:WikiProject Chemicals.
Capitalization
The names of chemical compounds are common nouns. They are capitalized at the beginning of a sentence or title, but not elsewhere.
Prefixes such as sec-, tert, ortho-, meta-, para- and the numerical prefixes are not considered part of the name: the first letter of main part of the name should still be capitalized where appropriate. The exception is iso-, which is part of the name and therefore not italicized or hyphenated. Substituent groups do form part of the name: hence the correct article title is 2-Aminoethanol, which is written as 2-aminoethanol if not at the start of a sentence. Note that the two wikilinks refer to separate articles: one is a redirect to the other.
See also
- List of organic compounds
- List of inorganic compounds
- Wikipedia:WikiProject_Chemicals
- Wikipedia:WikiProject_Chemicals/Style_guidelines
- Chemistry resources