IUPAC Nomenclature -Alphabetical Ligand Naming Rule

Order Strategy:

$$\text{IUPAC Name: } [\text{Counter Cation}] \quad \text{Ligands (Alphabetical)} + \text{Central Metal (Oxidation State)} \quad [\text{Counter Anion}]$$

Concept: Ligands are listed in strict alphabetical order based on their actual ligand name (ignoring prefixes like di-, tri-, bis-, tris-). In non-neutral complex spheres, anionic ligands take an "-o" suffix (e.g., $$\text{Cl}^-$$ becomes chlorido, $$\text{CN}^-$$ becomes cyanido), while neutral ligands retain standard names with explicit exceptions ($$\text{H}_2\text{O}$$ as aqua, $$\text{NH}_3$$ as ammine, $$\text{CO}$$ as carbonyl, $$\text{NO}$$ as nitrosyl).

Notation:

• Prefix bis-, tris-, tetrakis- are used when the ligand name itself already contains a numerical prefix (e.g., bis(ethane-1,2-diamine)).
• Roman numerals in parentheses indicate the formal oxidation state of the central metal center without space (e.g., $$\text{Cobalt(III)}$$).