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Chemical isomerism characterized by facile interconversion of isomeric forms in equilibrium, especially by migration of a hydrogen atom.

tau′to·mer (tô′tə-mər) n.
tau′to·mer′ic (tô′tə-mĕr′ĭk) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Chemistry) the ability of certain chemical compounds to exist as a mixture of two interconvertible isomers in equilibrium. See also keto-enol tautomerism
[C19: from tauto- + isomerism]
tautomeric adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(tɔˈtɒm əˌrɪz əm)

the ability of certain organic compounds to react in isomeric structures that differ from each other in the position of a hydrogen atom and a double bond.
[1880–85; tauto- + (iso) merism]
tau`to•mer′ic (-təˈmɛr ɪk) adj.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.


Tautomerism occurs when a compound exists as two different structural isomers that are in dynamic equilibrium with each other.
Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited
References in periodicals archive ?
Stilinovic, Schiff Bases Derived From Hydroxyaryl Aldehydes: Molecular And Crystal Structure, Tautomerism, Quinoid Effect, Coordination Compounds, Macedonian J.
You, "Azohydrazone tautomerism by in situ CuII ion catalysis and complexation with the [H.sub.2][O.sub.2] oxidant of C.I.
Abdallah, "Synthesis, azo-hydrazone tautomerism and antitumor screening of N-(3-ethoxycarbonyl-4,5,6,7-tetrahydro-benzo[b]thien-2-yl)-2-arylhydrazono-3- oxobutanamide derivatives," Arkivoc, vol.
The lower selectivity of these thiocarbonyl structures can be ascribed to the tautomerism between thiocarbonyl and thiol.
Influence of substituent on UV absorption and keto-enol tautomerism equilibrium of dibenzoylmethane derivatives.
Aroylhydrazones, mostly can exhibit keto-enol tautomerism (Figure-1), that is primarily due to the solvent/reagent effect, temperature change, UV irradiations or pH change.
Hydrazone Schiff base plays an important role in inorganic chemistry, as it can easily form stable complexes with most transition metal ions due to its ability to form keto-enol tautomerism (Figure 1) [1-4].
Rogers, "Keto-enol tautomerism in [beta]-dicarbonyls studied by nuclear magnetic resonance spectroscopy.
Tautomerism of the natural thymidine nucleoside and the antiviral analogue D4T.