Project Details Graphical Representation Standards for Chemical Reaction Diagrams

Project No.:
Start Date:
19 December 2017
End Date:


  • To extend IUPAC’s leadership in the development of standard nomenclature and terminology in chemistry and for guidelines in the representation of graphical chemical structures into the domain of chemical reaction diagrams.
  • To provide a single, comprehensive set of guidelines for creating chemical reaction diagrams in printed and in electronic media.
  • To enable IUPAC to serve as the principal, authoritative source for guidelines on the representation of chemical reactions.

The recommendations will incorporate and complement the work of the earlier project that produced extensive recommendations (project 2003-045-3-800):
Graphical representation standards for chemical structure diagrams, see J. Brecher, K. N. Degtyarenko, H. Gottlieb, R. M. Hartshorn, K.-H. Hellwich, J. Kahovec, G. P. Moss, A. McNaught, J. Nyitrai, W. Powell, A. Smith, K. Taylor, W. Town, A. Williams, A. Yerin, Pure Appl. Chem., 2008, 80(2), 277-410,, and
Graphical representation of stereochemical configuration, see J. Brecher, K. N. Degtyarenko, H, Gottlieb, R. M. Hartshorn, G. P. Moss, P. Murray-Rust, J. Nyitrai, W. Powell, A. Smith, S. Stein, K. Taylor, W. Town, A. Williams, A. Yerin, Pure Appl. Chem., 2006, 78(10), 1897-1970,


IUPAC has published recommendations for the graphical representation of chemical structure, and stereochemical configuration. These recommendations form the basis for reaction representation but do not deal with the layout features that apply to reactions. Although existing IUPAC nomenclature recommendations already discuss some aspects of chemical reaction diagrams, they do so only tangentially. Even if they were to be collected in one location, these existing recommendations on chemical reaction diagrams are incomplete, and do not discuss many basic issues. As a result, many organizations have formulated their own guidelines for creating chemical reaction diagrams; however, none of those guidelines is comprehensive. Provision of a single, comprehensive set of guidelines for creating chemical reaction diagrams would be a significant benefit to the chemistry community.

With the ever-increasing importance of electronic publication, this project will consider issues related to the production of chemical reaction diagrams both in printed and in electronic media. Where possible, every effort will be made to ensure identical recommendations in all media. The recommendations for the production of chemical reaction diagrams will aid in the correct recognition of reaction information by the IUPAC International Chemical Identifier (InChI) algorithm.

In some cases, the current state of chemistry software may preclude the use of the most-preferred styles for chemical reaction diagrams. When necessary, this project will also provide practical advice for the production of electronic chemical reaction diagrams according to the current state of the art of chemistry software. It is likely that this project will also produce a set of recommendations for enhancements that chemistry software developers may undertake to improve that state of the art.


The project began informally with a “scoping exercise” in which some members of the chemistry community were invited to discuss those aspects of creating chemical reaction diagrams which are amenable to standardization through IUPAC recommendations. The participants in the scoping exercise also identified several areas that are likely to be contentious or otherwise were incompletely specified; those areas will receive specific attention during the project. Project 2012-033-1-800 has made significant progress on a subset of the problem when the task group met in Istanbul in 2013.

This project will include three team meetings each of 2 days duration. The first meeting is planned for Cambridge, the second in Paris associated with the IUPAC General Assembly in July 2019. The location of the third will be set when the location of the appropriate Division VIII meeting is known.

Oct 2020 update – draft document available, under review with Div VIII

Page last updated 15 Oct 2020