IUPAC nomenclature of coordination compounds

IUPAC lays down a fixed set of rules for naming coordination compounds unambiguously. Rule 1: name the ligand(s) first, and only then the central metal. Rule 2: anionic ligand names are systematically modified -- an ending of '-ide' becomes '-o' (e.g. chloride -> chloro), and an ending of '-ate' becomes '-ato' (e.g. sulphate -> sulphato); Table 9.1 gives the full list of anionic and neutral ligand names used in this chapter (note the special, non-obvious spellings: NH3 as a ligand is 'ammine' -- with two m's, distinct from the organic 'amine' -- and H2O as a ligand is 'aqua'). Rule 3: the whole complex name is written as ONE continuous word, with no space anywhere between different ligand names or between the last ligand name and the metal name. Rule 4: the metal's oxidation state is written in Roman numerals, in parentheses, immediately after the metal name with no intervening space, e.g. platinum(IV). Rule 5: when a complex contains more than one ligand of the SAME type, the count is shown with the ordinary multiplying prefixes di- (2), tri- (3), tetra- (4), penta- (5), hexa- (6), and so on. Rule 6: when a complex contains ligands of DIFFERENT types, they are cited in strict alphabetical order by ligand name (ignoring any multiplying prefix) -- e.g. between a ligand set called 'tetraaqua' and one called 'dichloro', 'tetraaqua' is alphabetised on 'aqua' and so is cited first. Rule 7: if a ligand's OWN name already contains a numerical word (like ethylenediamine), an ordinary multiplying prefix would be ambiguous, so the special multiplying prefixes bis- (2), tris- (3), tetrakis- (4) etc. are used instead, with the whole ligand name enclosed in its own parentheses -- e.g. three ethylenediamine ligands is written tris(ethylenediamine), never 'triethylenediamine'. Rule 8: in a cationic or neutral complex the metal keeps its ordinary element name (e.g. platinum), but in an ANIONIC complex the metal's name is changed to end in '-ate' -- Table 9.2 lists several of these irregular '-ate' forms (e.g. iron -> ferrate, not 'ironate'; copper -> cuprate …