Ligands inorganic, nomenclature

The Commission on the Nomenclature of Inorganic Chemistry is currently producing a further volume of the Nomenclature of Inorganic Chemistry, which will deal with more specialised aspects of inorganic nomenclature not currently treated in the 1990 version. For example, one chapter will be devoted to the nomenclature of nitrogen hydrides, another to the nomenclature of iso- and heteropolyanions and yet another to techniques and recommendations for abbreviations of names, especially ligand names. These chapters are innovative but also codify a great deal of established practice. 

The second edition of the well-known Red Book, the definitive recommendations of the lUPAC Commission on Nomenclature of Inorganic Chemistry, appeared in Pure Appl. Chem., 28, 1-110 (1971). It is also available separately as a hard-bound reprint. In this edition, the rules for naming organometallic compounds have been completely revised and extended, with introduction of the rj nomenclature for organic ligands. 

This system is additive and was developed originally to name coordination compounds, although it can be used in other circumstances when appropriate. For a discussion, see the Nomenclature of Inorganic Chemistry, Chapter 10. The compound to be named is considered as a central atom together with its ligands, and the name is developed by assembling the individual names of the constituents. This system has also been applied to name oxoacids and the related anions. Coordination names for oxoanions are cited in the examples throughout the text, and they are presented in detail in Section 4.4.5 (p. 69). 

The nomenclature for describing optically active inorganic complexes and ligand conformations requires some discussion. Formerly, active... 

Coordination nomenclature. This is an additive system for inorganic coordination compounds which treats a compound as a combination of A central atom wiih associated ligands (see Section 1-10). 

IR-1.5.3.2 Compositional nomenclature IR-1.5.3.3 Substitutive nomenclature IR-1.5.3.4 Additive nomenclature IR-1.5.3.5 General naming procedures IR-1.6 Changes to previous IUPAC recommendations IR-1.6.1 Names of cations IR-1.6.2 Names of anions IR-1.6.3 The element sequence of Table VI IR-1.6.4 Names of anionic ligands in (formal) coordination entities IR-1.6.5 Formulae for (formal) coordination entities IR-1.6.6 Additive names of polynuclear entities IR-1.6.7 Names of inorganic acids IR-1.6.8 Addition compounds IR-1.6.9 Miscellaneous... 

Additive nomenclature treats a compound or species as a combination of a central atom or central atoms with associated ligands. The particular additive system used for coordination compounds (see Chapter IR-9) is sometimes known as coordination nomenclature although it may be used for much wider classes of compounds, as demonstrated for inorganic acids (Chapter IR-8) and organometallic compounds (Chapter IR-10) and for a large number of simple molecules and ions named in Table IX. Another additive system is well suited for naming chains and rings (Section IR-7.4 see Example 6 below). 

The relative ranking of ligands for the description of the stereochemical properties of a molecule is the most utilized and accepted principle throughout stereochemical nomenclature. This is not yet the practice, however, in discussing the stereochemistry in coordination and inorganic chemistry. In the context of coordination and inorganic chemistry, stereochemical information is either presented in the more traditional terminology, or more often by means of a stereospecific structural representation. 

Oxidation Numbei) from —III to +V seeNitrogen Inorganic Chemistr. Consequently, there are many different types of N-donor ligands incorporating different oxidation states and different types of metal-nitrogen bonding (1)-(14) with a sometimes complicated nomenclature. ... 

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