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IUPAC nomenclature for coordination compounds follows a systematic set of rules. The cation is always named before the anion, regardless of which is the complex ion. Within the coordination entity, ligands are named before the metal in alphabetical order, ignoring multiplying prefixes (di, tri, bis, tris).
Anionic ligands receive the -o suffix (chlorido, cyanido, hydroxido, sulphato, oxalato). Neutral ligands retain their names except four special cases: H2O = aqua, NH3 = ammine (double m), CO = carbonyl, NO = nitrosyl. Simple ligands use di/tri/tetra prefixes; complex ligand names (containing internal prefixes or parentheses-worthy names) use bis/tris/tetrakis with parentheses.
The metal name is given last. For cationic or neutral complexes, use the English name (cobalt, platinum, chromium). For anionic complexes, use the Latin-root name with -ate suffix: iron → ferrate, copper → cuprate, silver → argentate, gold → aurate, tin → stannate, lead → plumbate, platinum → platinate. The oxidation state follows in Roman numerals in parentheses.
Example: K3[Fe(CN)6] = potassium hexacyanidoferrate(III). [CoCl2(en)2]Cl = dichloridobis(ethylenediamine)cobalt(III) chloride. Common errors include incorrect alphabetical ordering, using wrong prefix type, forgetting Latin names for anionic complexes, and miscalculating oxidation states.