Writing and Systematic Nomenclature of Complexes

We ll now give some basic rules of the nomenclature and writing of complexes. We will discuss only the classical coordination compounds here. 

Roman numerals indicate the oxidation state of the metal in the complex. To simplify the writing, some ligands may be represented by standard symbols in the formula. This is the case of complex (22.5), in which the symbol en represents the ligand ethylenediamine  

The symbol r (hapto ) gives a supplementary topological description of the complex by indicating the connectivity of the ligand and of the central atom. It is written 

22 General Definitions Concerning Complexes Rules of Nomenclature and Writing 

Remark The representation of a complex between brackets may be confused with its concentration, which is also systematically written between brackets, and also, in some cases, with its activity. A complex s concentration is not represented by several sets of brackets. In this case, only the brackets of the concentration exist, but the complex s charge must be included within the brackets. 

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