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An atom or group substituted for another in a chemical compound.
Of or relating to such an atom or group.

[Latin substituēns, substituent-, present participle of substituere, to substitute; see substitute.]
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) chem an atom or group that replaces another atom or group in a molecule or can be regarded as replacing an atom in a parent compound
substituted or substitutable
[C19: from Latin substituere to substitute]
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(sʌbˈstɪtʃ u ənt)

an atom or atomic group that takes the place of another atom or group present in the molecule of the original compound.
[1890–95; < Latin substituent-, s. of substituēns, present participle of substituere to substitute; see -ent]
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
References in periodicals archive ?
In addition, more regular belt-like or fiber-like aggregates with different aspect ratios were prepared in gels of TC16-S and TC16-N with three alkyl substituent chains in molecular skeletons.
and methylene protons, respectively: and [DELTA][zeta] is the protonational chemical shift increase of the substituent groups.
Quantum chemical calculations were carried out to explain how the electronic state and reactivity indices of some methylated benzo [a] anthracenes vary with position and number of methyl substituent in molecules.
Log P estimates the logarithmic octanol-water partition coefficient, therefore the Log P represents the lipophilic effects of a molecule which includes the sum of the lipophiliccontributions of the parent molecule and its substituent [25].
The inhibitory effects of these HAQs might be related with the type and number of substituent groups on the molecular structure, and the stability and solubility of the particular compound.
In other cases, an adversarial substance may be an environmental substituent whose profile of toxicity plus occurrence is far less threatening than the effect of a more prevalent substance that merely has the good fortune of not being associated with a politically convenient target, such as a military-industrial enterprise.
An interesting feature of the tetrahydroisoquinoline alkaloids of peyote is the existence of a methylenedioxy substituent on the aromatic ring, in contrast to the three methoxy groups in mescaline.
Norbloc 7966 benzotriazole uv stabilizer has a methacrylate ester substituent, which will copolymerize efficiently with various vinyl monomers.
The clusters without substituent groups were found to have quite modest acidity, both systems staying above 300 kcal/mol.
The term phenol, or phenol compound, embraces a wide range of substances that possess an aromatic carbon ring bearing an OH group, or hydroxyl substituent, including their functional derivatives.
Biological apatites are rarely stoichiometric, are usually calcium-deficient, and contain a wide variety of relatively small amounts of other substituent atoms or groups.
The new method for making stable carbenes, reported in the June 8 SCIENCE, is simpler: Just one substituent must have electron-moving ability.