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Alignment of principles for specifying ligands and substituent groups across various areas of nomenclature

Published/Copyright: August 6, 2018
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Chemistry International
From the journal Chemistry International Volume 40 Issue 3

During the review of the project on boron hydride nomenclature by the Chemical Nomenclature and Structure Representation Division, (Division VIII) in the first half of 2016, inconsistencies in the use of kappa (κ) symbols were noticed. Further, it became apparent that the approach followed until then, namely to use kappa terms at the end of a ligand name otherwise unchanged as compared to the non-ligated species, is not feasible. This raised the question of how to handle substituents in a ligand with different ligating atoms/kappa terms. The logical step was to look for precedent in similar situations, e.g., isotopically modified substituents. However, when comparing the possible approaches, it was further noticed that inconsistencies exist in the Blue Book concerning the treatment of substituents with different kinds of modification, specifically when lambda symbols, stereodescriptors, or isotopic modifications are added. The Blue Book task group had already decided that, in the alphabetical ordering of substituents, an unmodified substituent is always to be listed before the same, but modified substituent—the “nothing before something” principle approved by the Division Committee. With the return of this question, concerns about the consequences for numbering arose.

A project was initiated to provide the basis for the completion of several projects with different states of progress:

  1. Boron hydride nomenclature (2012-045-1-800)

  2. Metallacycles nomenclature (2013-030-1-800)

  3. Preferred names for inorganic compounds (kappa document) (2006-038-1-800)

  4. Blue Book revision and extension (2015-052-1-800)

  5. Inorganic and coordination polymers (2011-035-1-800)

The task group will review the inconsistent sections in the Blue Book and sections on comparable situations in the Red Book and then find a consensus on:

  1. the grouping of substituents or ligands with different kinds of modifications

  2. the alphabetical order of substituents or ligands with different kinds of modifications

  3. the positioning of locants for substituents and ligands in chemical names

  4. the positioning and grouping of kappa terms in chemical names

For further information, contact the Task Group Chair Karl-Heinz Hellwich <> www.iupac.org/project/2017-033-1-800

Published Online: 2018-08-06
Published in Print: 2018-07-01

©2018 IUPAC & De Gruyter. This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License. For more information, please visit: http://creativecommons.org/licenses/by-nc-nd/4.0/

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https://doi.org/10.1515/ci-2018-0313

Articles in the same Issue

  1. Masthead - Full issue pdf
  2. Secretary General's Column
  3. IUPAC Large or Small? Some Fractal Character?
  4. Stamps International
  5. Nitrogen Fixation before Haber
  6. Features
  7. The Future of the Chemical Sciences
  8. Chemistry in a Multidisciplinary, Interdisciplinary World
  9. IUPAC and IYCN: Forging New Connections to Support Younger Chemists Worldwide
  10. The Gender Gap in Science
  11. Chemistry in Senegal: Between Skepticism and Hope
  12. IUPAC Wire
  13. Seth Herzon is the recipient of the 2018 Thieme-IUPAC Prize
  14. Andreas Walther receives the Hanwha-Total IUPAC Young Scientist Award 2018
  15. Chris Brett awarded the medal of CCS
  16. IUPAC Announces the Winners of the 2018 IUPAC-Solvay International Award for Young Chemists
  17. IUPAC 2019 Distinguished Women in Chemistry or Chemical Engineering—Call for Nominations
  18. Project Place
  19. Alignment of principles for specifying ligands and substituent groups across various areas of nomenclature
  20. Expression of uncertainty in measurement
  21. DIGChem—a vision for chemical data standards
  22. Collection, compilation and evaluation of elemental and isotopic data of calcium carbonate and hydroxyapatite materials and the assessment of their usability to act as reference materials
  23. Glossary of terms used in biochar research
  24. IUPAC100 Global Breakfast
  25. Making an imPACt
  26. Terminology of bioanalytical methods (IUPAC Recommendations 2018)
  27. Reorienting chemistry education through systems thinking
  28. Clarification of the term “normal material” used for standard atomic weights (IUPAC Technical Report)
  29. Corrigendum
  30. Up for Discussion
  31. Consideration of the sequence rule in rule P-94.2
  32. Bookworm
  33. Comprehensive Glossary of Terms Used in Toxicology
  34. Chemistry Teacher International, best practices in chemistry education
  35. The IUPAC Green Book in Portuguese
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  40. Croatian Meeting of Chemists and Chemical Engineers
  41. Crossing Divides—Science Towards Peace in the Middle East
  42. Mark Your Calendar
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