Wikipedia:WikiProject Chemicals/Style guidelines

These guidelines have been put together by the WikiProject Chemicals to help editors improve the 4000 or so articles on Wikipedia which are about chemical compounds.

Title

There is a misconception among certain editors that the title of a chemical compound article must be the systematic name of the compound: this is not always the case.

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 ^[1] 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 was felt necessary to standardize these spellings as follows:^[2]

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." These are based on "preferred names" in IUPAC nomenclature.

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 covalancy 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.

Article format

Infobox

Wikipedia:WikiProject Chemicals strongly recommends the use of chemical infoboxes for the following reasons:

If basic (often numerical) data is included in the article text, the readability of the article is reduced.
They reflect a certain consensus as to what data is appropriate for an encyclopedic article.
They promote a common visual style among Wikipedia articles on a given subject area.
They are well supported by the MediaWiki software (unlike HTML tables), and easily adapted (by individual editors) to the different needs of different articles.

The chembox to use is {{Chembox new}}. It is a modular, expandable infobox. Just use the parameters which you need; empty values will not be displayed.

To include a chembox in an article:

Open {{Chembox new}} and copy the relevant (simple, medium, full) box desired, and paste into a text editor
Open the relevant reference (e.g. MSDS, Merck Index, CRC Handbook, etc.) and input the data into the template
Copy the filled-out template into the relevant Wikipedia article.

For formatting reasons, the code for the infobox should be at the very beginning of the source code.

Introductory paragraph

See also: Wikipedia:Lead section

Occurrence

If the compound occurs naturally, it can be mentioned here. If natural sources are industrially significant, some discussion should be included. Avoid one-sentence sections — such data can be left in the lead.

Preparation

All articles about chemical compounds should include one or more methods of preparation:

laboratory-scale preparation
industrial production
biosynthesis

as appropriate. Depending on the length, these different styles of synthesis may merit full-fledged headers. Even articles about chemicals that are normally extracted from minerals (e.g. molybdenum disulfide) should normally have a laboratory route to the same compound. Mention should be made if a compound is routinely available commercially.

Where appropriate, the first synthesis/first characterization of each compound should be mentioned and referenced to the original article. Apart from that, foolproof syntheses such as those listed in Organic Syntheses and Inorganic Syntheses are preferred. Patented syntheses should be phrased carefully — e.g. "xxx may be synthesized from ... " Being patented does not mean that this synthesis is the best, or that it is used industrially.

Uses and/or reactions

Applications which are most familiar to the lay reader should be listed first. Those requiring more than a cursory knowledge of chemistry should be left at the back. Avoid lists: try to group the various uses by similarity into a coherent paragraph. The applications listed need not be exhaustive.

If reactions are to be described, list the "proven" reactions (i.e. what you would find in Organic and Inorganic Syntheses) first. Other more exotic reactions which perhaps do not work all the time (such as that found in a journal) should be listed later.

History

This is an optional paragraph. The history section should include the discovery/first synthesis of this compound. Past industrial processes can be described as well. If the etymology of the compound is complicated, it can be included here as well, instead of in the lead.

Safety

The hazards associated with a chemical compound should usually be described in the Chembox (via EUClass, NFPA, or MainHazard parameters; further elaborated in R and S phrases). If the hazards are trivial, do not create a separate sub-section here. The mention in the Chembox is sufficient. In plain English, avoid one-sentence sections stating "Water is harmful when ingested in large quantities."

If there is something to be said about the safety, do make use of reliable sources in the form of inline citations.

Two main rules:

The description of hazards should avoid speculation. This is partly an extension of Wikipedia NPOV policy, but not entirely. There is no need to include a section which merely states "all chemical compounds should be treated with the utmost precaution": such a section tells the reader nothing. If there are no known (or reasonably suspected) hazards, there is nothing for Wikipedia to say.
The description of hazards should avoid hyperbole. The role of Wikipedia is to give balanced and accurate information, to allow its readers to reach their own conclusions.

Descriptions of hazards should, as far as possible, be based on published, peer-reviewed sources (which should, of course, be cited at the appropriate point in the article). A list of resources for chemical safety information is given in the external links section of these guidelines.

Toxicology

Toxicology may be found as a daughter section of safety, or may be a full fledged section of its own. It all depends on how much information is contained here, and the emphasis. If the compound is a drug, follow Wikipedia:WikiProject Drugs' recommendations.

Suppliers

Do not include suppliers information as they are spam magnets. Such lists are unmaintainable and tempt all sorts of people to add their favorite chemical supply house. Exceptions are, if the particular chemical is only produced by one or two suppliers, and thus is hard to find or get.

References

See: Wikipedia:Footnotes, Wikipedia:Cite your sources

There is consensus that the <ref> style of inline citations is to be used throughout articles concerning chemicals. It is preferable to use {{cite journal}}, {{cite encyclopedia}}, and {{cite web}}, though this is not mandatory. For papers published in Organic Syntheses, there is a special citation template ({{OrgSynth}}), which is simpler to fill in.

References should come in a numbered list immediately before the External links section. If footnotes are also used, these should be interspersed with the references and the heading changed accordingly. Notes and references should be numbered sequentially throughout the article by superscript Arabic numerals.

There is no consensus in Wikipedia as a whole for the format of the references, although APA style is suggested as a guideline: this is almost identical to the style used in ACS journals such as J. Am. Chem. Soc. Wikipedia offers a number of citation templates which reproduce this style.

Some commonly used textbook have their own citation templates:

Template	Reference
{{Cotton&Wilkinson4th}}	Cotton, F. Albert; Wilkinson, Geoffrey (1980), Advanced Inorganic Chemistry (4th ed.), New York: Wiley, ISBN 0-471-02775-8
{{Cotton&Wilkinson6th}}	Cotton, F. Albert; Wilkinson, Geoffrey; Murillo, Carlos A.; Bochmann, Manfred (1999), Advanced Inorganic Chemistry (6th ed.), New York: Wiley-Interscience, ISBN 0-471-19957-5
{{Greenwood&Earnshaw}}	Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN 978-0-08-037941-8.
{{March4th}}	March, Jerry (1992), Advanced Organic Chemistry: Reactions, Mechanisms, and Structure (4th ed.), New York: Wiley, ISBN 0-471-60180-2
{{McMurray}}	McMurry, John E. (1992), Organic Chemistry (3rd ed.), Belmont: Wadsworth, ISBN 0-534-16218-5
{{Merck12th}}	Budavari, Susan, ed. (1996), The Merck Index: An Encyclopedia of Chemicals, Drugs, and Biologicals (12th ed.), Merck, ISBN 0911910123
{{RubberBible53rd}}	Weast, R. C., ed. (1972). Handbook of Chemistry and Physics (53rd ed.). Cleveland, OH: Chemical Rubber Co.
{{RubberBible83rd}}	Lide, D. R., ed. (2002). CRC Handbook of Chemistry and Physics (83rd ed.). Boca Raton, FL: CRC Press. ISBN 0-8493-0483-0.
{{RubberBible86th}}	Lide, D. R., ed. (2005). CRC Handbook of Chemistry and Physics (86th ed.). Boca Raton (FL): CRC Press. ISBN 0-8493-0486-5.
{{Stryer}}	Stryer, L.; Berg, J. M.; Tymoczko, J. L. (2002), Biochemistry (5th ed.), New York: W. H. Freeman, ISBN 0716746840
{{VogelOrganic}}	Furniss, B. S.; Hannaford, A. J.; Smith, P. W. G.; Tatchell, A. R. (1989), Vogel's Textbook of Practical Organic Chemistry (5th ed.), Harlow: Longman, ISBN 0-582-46236-3
{{VogelQualitative}}	Vogel, Arthur I.; Svehla, G. (1979), Vogel's Textbook of Macro and Semimicro Qualitative Inorganic Analysis (5th ed.), London: Longman, ISBN 0-582-44367-9 – via the Internet Archive
{{VogelQuantitative}}	Mendham, J.; Denney, R. C.; Barnes, J. D.; Thomas, M. J. K. (2000), Vogel's Quantitative Chemical Analysis (6th ed.), New York: Prentice Hall, ISBN 0-582-22628-7

External links

Avoid adding external links to general sites. Rather, link to the particular article which is relevant. There is absolutely no need to link every national or state regulatory body for a regulated chemical. Instead, use them as inline references in the body of the article, if necessary.

A certain number of frequently used sites have their own templates for the external link:

Template	Link
{{ecb}}	Template:Ecb
{{nist}}	Linstrom, Peter J.; Mallard, William G. (eds.); NIST Chemistry WebBook, NIST Standard Reference Database Number 69, National Institute of Standards and Technology, Gaithersburg (MD)
{{ICSC\|xxyy\|xx}}	International Chemical Safety Card xxyy
{{inrs}}	Institut national de recherche et de sécurité ({{{year}}}). "{{{title}}}." Fiche toxicologique n° {{{number}}}. Paris:INRS. (in French)
{{PubChemLink\|xxx}}	CID xxx from PubChem
{{SDBS}}	Template:SDBS
{{webelements}}	Template:Webelements

Interwiki links

References

^ Panico, R.; & Powell, W. H. (Eds.) (1994). A Guide to IUPAC Nomenclature of Organic Compounds 1993. Oxford: Blackwell Science. ISBN 0-6320-3488-2.{{cite book}}: CS1 maint: multiple names: authors list (link)
^ Leigh, G. J. (Ed.) (1990). Nomenclature of Inorganic Chemistry. Recommendations 1990. Oxford: Blackwell Science. ISBN 0-6320-2494-1.

External links

Royal Society of Chemistry Author Guidelines

Nomenclature

IUPAC Provisional Recommendations for the Nomenclature of Inorganic Chemistry (2004)
IUPAC Nomenclature of Organic Chemistry (online version of the "Blue Book")
IUPAC Recommendations on Organic & Biochemical Nomenclature, Symbols, Terminology, etc. (includes IUBMB Recommendations for biochemistry)
IUPAC Abbreviated list of quantities, units and symbols in physical chemistry (online version of the "Green Book")
IUPAC Compendium of Chemical Terminology (online version of the "Gold Book", from IUPAC)
IUPAC Compendium of Chemical Terminology (online version of the "Gold Book", from the RSC, allows free text searching)

Properties

Safety information

Suppliers

`α`	α	`Α`	Α
`β`	β	`Β`	Β
`γ`	γ	`Γ`	Γ
`δ`	δ	`Δ`	Δ
`ε`	ε	`Ε`	Ε
`ζ`	ζ	`Ζ`	Ζ
`η`	η	`Η`	Η
`θ`	θ	`Θ`	Θ
`ι`	ι	`Ι`	Ι
`κ`	κ	`Κ`	Κ
`λ`	λ	`Λ`	Λ
`μ`	μ	`Μ`	Μ
`ν`	ν	`Ν`	Ν
`ξ`	ξ	`Ξ`	Ξ
`ο`	ο	`Ο`	Ο
`π`	π	`Π`	Π
`ρ`	ρ	`Ρ`	Ρ
`σ`	σ	`Σ`	Σ
`τ`	τ	`Τ`	Τ
`υ`	υ	`Υ`	Υ
`φ`	φ	`Φ`	Φ
`ψ`	ψ	`Ψ`	Ψ
`χ`	χ	`Χ`	Χ
`ω`	ω	`Ω`	Ω

Title

General rule

IUPAC preferred name vs. systematic name

Element names

Use of Stock nomenclature

Drug-related articles

Prefixes

Redirects

Exceptions

Article format

Infobox

Introductory paragraph

Occurrence

Preparation

Uses and/or reactions

History

Safety

Toxicology

Suppliers

See also

References

External links

Categories

Interwiki links

Articles from other WikiProjects

WikiProject Drugs

WikiProject Elements

WikiProject Rocks and Minerals

WikiProject Polymers

Other topics

Capitalization (English language convention)

Special symbols

Greek letters

Arrows

Other symbols

Chemical structures and reaction schemes

Units

Experimental details

See also

References

External links

Nomenclature

Properties

Safety information

Suppliers