Page 77 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

IR-5 Compositional Nomenclature, and

Overview of Names of Ions and Radicals

C O N T E N T S

IR-5.1 Introduction
IR-5.2 Stoichiometric names of elements and binary compounds
IR-5.3 Names of ions and radicals
IR-5.3.1 General
IR-5.3.2 Cations
IR-5.3.2.1 General
IR-5.3.2.2 Monoatomic cations
IR-5.3.2.3 Homopolyatomic cations
IR-5.3.2.4 Heteropolyatomic cations
IR-5.3.3 Anions
IR-5.3.3.1 Overview
IR-5.3.3.2 Monoatomic anions
IR-5.3.3.3 Homopolyatomic anions
IR-5.3.3.4 Heteropolyatomic anions
IR-5.4 Generalized stoichiometric names
IR-5.4.1 Order of citation o f e lectropositive and electronegative constituents
IR-5.4.2 Indication of proportions of constituents
IR-5.4.2.1 Use of multiplicative prefixes
IR-5.4.2.2 Use of charge and oxidation numbers
IR-5.4.2.3 Multiple monoatomic constituents vs. h omopolyatomic c onstituents
IR-5.5 Names of (formal) addition compounds
IR-5.6 Summary
IR-5.7 References

IR-5.1 I N T R O D U C T I O N

Compositional nomenclature is formally based on composition, not structure, and may thus
be the (only) choice if little or no structural information is available or a m inimum of
structural i nformation is to be conveyed.
The simplest type of compositional name is a stoichiometric name, which is just
a r eflection of the empirical formula ( Section IR-4.2.1) or the molecular formula (Section
IR-4.2.2) of the compound. In stoichiometric names, proportions of constituent e lements
may be indicated in several ways, using m ultiplicative p refixes, oxidation numbers or charge
numbers.
In some cases, a c ompound may be regarded as composed of constituents that may
themselves be given n ames of any of several types (including stoichiometric names); the

68