Donor-atom symbol

Donor atom symbol as the Index. A polydemate ligand possesses more than one donor site, some or all or which may be involved in coordination. Thus, dithiooxatale anion conceivably may be attached through 5 or O. and these were distinguished by dithioox-alalo-J.S and dithiooxalutO-0.0, respectively. 

The order of citation of central atoms is based on electronegativity as described in Section IR-4.4.2.1. Ligands are cited alphabetically (Section IR-4.4.2.2) according to the first symbol of the ligand formula or ligand abbreviation (see Section IR-4.4.4) as written. Where possible, the ligand formula should be written in such a way that a/the donor atom symbol is closest to the symbol of the central atom to which it is attached. 

IR-9.2.4.3 Comparison of the eta and kappa conventions IR-9.2.4.4 Use of donor atom symbol alone in names IR-9.2.5 Polynuclear complexes IR-9.2.5.1 General IR-9.2.5.2 Bridging ligands IR-9.2.5.3 Metal-metal bonding IR-9.2.5.4 Symmetrical dinuclear entities IR-9.2.5.5 Unsymmetrical dinuclear entities... 

The following sections detail the means by which donor atoms are specified. The kappa (k) convention, introduced in Section IR-9.2.4.2, is general and can be used for systems of great complexity. In some cases it may be simplified to the use of just the donor atom symbol (see Section IR-9.2.4.4). 

These systems may be used in names, but they are not always suitable for use in formulae. The use of donor atom symbols is possible in the formulae of simple systems (see Section IR-9.2.3.4), but care must be taken to avoid ambiguity. The kappa convention is not generally compatible with the use of ligand abbreviations. 

Multiplicative prefixes which apply to a ligand or portions of a ligand also apply to the donor atom symbols. In some cases this may require the use of an alternative ligand name, e.g. where multiplicative prefixes can no longer be used because the ligation of otherwise equivalent portions of the ligand is diflFerent. Several examples of this are given below. 

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