|MadSci Network: Chemistry|
Whenever you have any question on how to give name to a chemical compound, the first place you must look at is the IUPAC . This is the international organization for chemists to agree on the rules to be followed all over the world, so scientists from any country can make sure they are talking about the same thing or not. The IUPAC organize the information in different "coloured" books: Blue for organic chemistry  Gold for combined glossary  Green for physical chemistry  Orange for analytical chemistry  Purple for macromolecular chemistry  Red for inorganic chemistry  Silver for clinical chemistry  and White for biochemical chemistry  On regards to your question, the term "tris" corresponds to the numerical indexing of complex features (e.g. substituted substituents), which are named "-kis" after the corresponding numerical prefix, except for one (obviously), two (bis) and three (tris) [10, 11]. I have found no further rules about the spelling of this particle so I think low case should be used when not at the beginning of the sentence. But you could be talking about the common, non systematic, name given to the 2-amino-2-hydroxymethyl-propane-1,3-diol. Image of the compound: http://en.wikipedia.org/wiki/File:Tris.png This is also known as Tris buffer, Tris base or just TRIS, and it can be found in Sigma-Aldrich catalogue as Trizma(TM) . As these are not the systematic names of the compound and they may lead to confusion with the numerical index it is important to show the difference. So for the sake of clarity and ease of communication, the more common way of naming this compound, and the first step to a final global agreement, is TRIS, written in capital letters. References  http://www.iupac.org/ and http://www.chem.qmul.ac.uk/iupac/index.html  Nomenclature of Organic Chemistry, Sections A, B, C, D, E, F, and H, Pergamon Press, 1979. Edited by J Rigaudy and S P Klesney. [ISBN 0-08-022369-9]  Compendium of Chemical Terminology, Blackwell Scientific Publications, 1987. Edited by V Gold, K L Loening, A D McNaught and P Sehmi. [ISBN 0-632-01765-1; 0-632-01767-8 (pbk)] Second edition, 1997. Edited by A D McNaught and A Wilkinson [ISBN 0-8-654-26848].  Quantities, Units and Symbols in Physical Chemistry, 3rd edition, RSC Publishing, 2007. Edited by I Mills. [ISBN 9780-85404-433-7]  Compendium of Analytical Nomenclature, 3rd edition, edited by J Inczedy, Blackwell Scientific Publications, 1998. [ISBN 0-86542-615-5]  Compendium of Macromolecular Nomenclature, Blackwell Scientific Publications, 1991. Edited by W V Metanomski. [ISBN 0-632-02846-7; 0-632-02847-5 (pbk)]  Nomenclature of Inorganic Chemistry: IUPAC Recommendations 2005, Royal Society of Chemistry, 2005. Edited by N G Connelly and T Damhus (with R M Hartshorn and A T Hutton) [ISBN 0-85404-438-8].  Compendium of Terminology and Nomenclature of Properties in Clinical Laboratory Sciences, Blackwell Science, 1995. Edited by J C Rigg, S S Brown, R Dybkaer and H Olesen. [ISBN 0-865-426120]  Biochemical Nomenclature and Related Documents, 2nd edition, Portland Press, 1992. Edited C Liébecq. [ISBN 1-85578-005-4]  N. Lozac'h Pure Appl. Chem., 1986, 58, 1693-1696.  http://www.chem.qmul.ac.uk/iupac/misc/numb.html  http://www.chemindustry.com/chemicals/657845.html
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