Retained name

In chemistry, a retained name is a name for a chemical that does not follow the rules of a systematic name, but that is still allowed as a name in that system. Retained names can be trivial names or part of an older system of names.

Normally retained names are older than the rules and are used so that new work uses the same names as older work.

Examples

The light alkanes all use retained names: CH4 is methane (not carbane), C2H6 is ethane (not dicarbane), C3H8 is propane (not tricarbane), and C4H10 is butane (not tetracarbane).[1] Systematic names are used for their structural analogues with heavier atoms, like disilane for Si2H6.

Aromatic compounds and heterocyclic compounds commonly have retained names, as systematic names of these compounds that did not use retained names as a basis would be very complicated. Consider the following possible names for the common biomolecule purine (in its most common tautomer):

Retained name 9H-purine
Retained names for single cycles 7H-imidazo[4,5-d]pyrimidine
Retained name for bicyclic parent 1H-1,3,4,6-tetraazaindene
No retained names 2,4,7,9-tetraazabicyclo[4.3.0]nona-1,3,5,8-tetraene

Sources

  1. ↑ IUPAC Chemical Nomenclature and Structure Representation Division (2013). "P-21.2.1". In Favre, Henri A.; Powell, Warren H. (eds.). Nomenclature of Organic Chemistry: IUPAC Recommendations and Preferred Names 2013. IUPAC–RSC. ISBN 978-0-85404-182-4.
This article is issued from Wikipedia. The text is available under Creative Commons Attribution-Share Alike 4.0 unless otherwise noted. Additional terms may apply for the media files.