Chains and rings nomenclature

As an alternative to the procedure above, a group of atoms forming a chain or ring sub-structure within a compound may be chosen in order to give the compound an additive name using the chains and rings nomenclature outlined in Section IR-7.4. 

This compound has also been named, in Section II-5.3.3.3.6 of Ref. 7, using the chain and ring nomenclature (see Section IR-7.4). However, that name is based on a completely different numbering scheme. 

Table X Anion names, a terms used in substitutive nomenclature and y terms used in chains and rings nomenclature...

Polynuclear inorganic compounds exist in a bewildering array of structural types, such as ionic solids, molecular polymers, extended assemblies of oxounions both of metals and nonmeinis, nonmetal chains and rings, bridged melui complexes, and homo- and hetero-nuclcar clusters. This section treats primarily the nomenclature of bridged metal complexes and homo- and hetero-nuclear dusters. 

Sulfane oxides are compounds of type R2S Om ( > 1, m = 1, 2, 3...) with the oxygen atoms present as sulfoxide or sulfone groups. For the nomenclature of organic sulfur-oxygen compounds see Table 2 for reviews on oxidized sulfur chains and rings, see Steudel. Disulfane 1-oxides, RS(0)-SR, are also known as thiosulfinates and the 1,1-dioxides are usually termed as thiosulfonates. Trisulfane 1-oxides and 1,3-dioxides, as well as tetrasulfane 1-oxides and 1,4-dioxides, have been obtained by stepwise oxidation of the corresponding sulfanes by peroxy acids (equations 151 153) 67,101,123,127,262 26s... 

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). 

Nomenclature of Inorganic Chains and Ring Compounds, E.O. Fluck and R.S. Laitinen, Pure Appl. Chem., 69, 1659-1692 (1997). 

The designation of central atom and ligands, generally straightforward in mononuclear complexes, is more difficult in polynuclear compounds where there are several central atoms in the compound to be named, e.g. in polynuclear coordination compounds, and chain and ring compounds. In each case, a priority order or hierarchy has to be established. A hierarchy of functional groups is an established feature of substitutive nomenclature Table VI shows an element sequence used in compositional and additive nomenclature. 

Nomenclature of Inorganic Chains and Ring Compounds, E.O. Pluck and R.S. Laitinen, Pure Appl. Chem., 69, 1659-1692 (1997) Chapter II-5 in Nomenclature of Inorganic Chemistry II, IUPAC Recommendations 2000, eds. J.A. McCleverty and N.G. Connelly, Royal Society of Chemistry, 2001. 

Terminal vowel in prefixes used in specifying chain and ring atoms in additive nomenclature for inorganic chains and rings, cf. Section IR-7.4. These prefixes are given for all elements in Table X. 

During the last phase of the cycle hierarchically ordered objects (functional groups, chains, and ring systems) are related with the corresponding text fragments (determined by the syntax rules of lUPAC nomenclature) which are then compiled using appropriate lUPAC recommendations into the complete name of the input structure. 

Initially, the phane concept was intended solely for supercyclic systems, namely, cyclophanes. During elaboration of the new all-encompassing cyclophane nomenclature it became more and more obvious that its basic principles apply equally well to extended linear assemblies of chain and ring segments. Such superchains can then be treated exactly like cyclophanes, except that their names end with the morpheme... phane after the numerical term denoting the length of the superchain. 

---