IUPAC

To develop rules for choosing the Preferred IUPAC Names (PIN) for inorganic compounds, including coordination compounds, organometallic compounds, and compounds that either do not contain carbon, or do contain at least one element from groups 1-12. These rules should result in names that are suitable for use in legal and regulatory documentation.

The PIN concept has been developed in response to the difficulties that users of nomenclature strike when there is more that one systematic way of naming a compound. This issue is particularly problematic in legal and regulatory applications, where confusion over names could have major health and safety, legal, or financial implications.

Rules for choosing PINs for organic molecules have been developed as a major goal of the project for the revision of the Blue Book (project 2001-043-1-800). That project is nearing completion, and the resulting manuscript is in the IUPAC review process. It is obvious that PINs must also be available for inorganic compounds, but the methods that are typically used to name such compounds are different from those used for organic compounds, and consequently new rules will have to be developed.

A number of critical issues will have to be addressed; these include:

• choice of central atom(s), particularly in polynuclear species;
• clear definition of grammatical rules for the placement of k/h symbols in complicated ligand names;
• selection of retained names, particularly for oxo-acids.

Once these issues have been addressed, the proposals that are developed will be submitted to the IUPAC review process. Further documents will then be prepared that provide detailed guidance for selecting PINs for particular classes of compounds (coordination compounds, organometallic compounds, main group compounds).