Oxidation states coordination-type nomenclature

VI (d2), and the examples in Table 1 illustrate the kinds of complexes formed and their stereochemistries. Several of these oxidation states are not well characterized the — I and V states are rare, while I is not common. The most frequently encountered oxidation states in complexes of a conventional coordination type (particularly in aqueous media) are II (ds) and III (ds) the ferrous and ferric states respectively. The preferred nomenclature, and that used here, indicates these oxidation states as iron(II) and iron(III). 

As in the nomenclature of other inorganic compounds, specific rules are followed for naming coordination compounds. In general, the number and type of ligands attached to the metal ion are specified, as is the oxidation state of the metal ion. 

The nomenclature of simple coordination compounds is developed in a set of rules for referring to ionic and neutral ligands, the number of each type of ligand, and the oxidation state of the metal. A number of examples of naming compounds and writing formulas are given. 

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