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Atoms or groups of a molecule which are related by an n-fold rotation axis (n = 2, 3, etc.) are called homotopic. For example, chiral tartaric acid (C 2 axis), chloroform (C 3 axis) and cyclohexaamylose (α-cyclodextrin, C 6 axis) have respectively two homotopic carboxyl groups, three homotopic chlorine atoms and six homotopic d-glucose residues.
PAC, 1996, 68, 2193 (Basic terminology of stereochemistry (IUPAC Recommendations 1996)) on page 2210
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IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8.
Last update: 2014-02-24; version: 2.3.3.
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