Page 160 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

IR-9.2 C O O R D I N A T I O N C O M P O U N D S

For example, one would use diammine f or (NH 3 ) 2 , b ut bis(methylamine) for (NH 2 Me) 2 ,
to make a distinction from dimethylamine. There is no elision of vowels or use of a h yphen,
e.g. in tetraammine a nd similar names.

IR-9.2.2.3 Representing ligands in names

Systematic and alternative names for some common ligands are given i n T ables V II and IX.
Table VII c ontains the names of common organic ligands whereas Table IX contains t he names
of other simple m olecules and ions that may act as ligands. The general features are as follows:

(i) Names of anionic ligands, w hether i norganic or organic, are modified to end in ‘o’.
In general, i f t he anion name ends in ‘ide’, ‘ite’ or ‘ate’, the final ‘e’ is replaced b y ‘ o’,
giving ‘ido’, ‘ito’ and ‘ato’, respectively. In particular, alcoholates, thiolates,
phenolates, carboxylates, partially dehydronated amines, phosphanes, etc. a re in this
category. Also, it follows that halide ligands are named fluorido, chlorido, bromido and
iodido, and coordinated cyanide is named cyanido.
Initscomplexes,exceptforthoseof molecular hydrogen,hydrogen i s a lwaystreated a s
anionic. ‘Hydrido’ i s u sed f or hydrogen c oordinating to all elements including b oron. 3
4
(ii) Names of neutral and cationic ligands, i ncluding organic ligands, are used without
modification (even if they carry the endings ‘ ide’, ‘ite’ or ‘ate’; see Examples 8 a nd 14
below).
(iii) Enclosing m arks are required for neutral and cationic ligand names, for names of
inorganic anionic ligands containing multiplicative prefixes (such a s t riphosphato), for
compositional names (such a s c arbon disulfide), for names of substituted organic ligands
(even if there is no ambiguity in their use), and wherever necessary t o a void ambiguity.
However, common ligand names such as aqua, ammine, carbonyl, n itrosyl, methyl, e thyl,
etc., do not require enclosing marks, unless there is ambiguity when they are absent.
(iv) Ligands binding to metals through carbon atoms are treated in Chapter I R-10 on
organometallic compounds.

Examples:

Formula Ligand name
1. Cl chlorido

2. CN cyanido
3. H hydrido 3
3
2
2

4. D or H deuterido or [ H]hydrido 3
5. PhCH 2 CH 2 Se 2-phenylethane-1-selenolato
6. MeCOO acetato or ethanoato
7. Me 2 As dimethylarsanido
acetamide (not acetamido)
8. MeCONH 2
9. MeCONH acetylazanido or acetylamido (not acetamido)
methanamine
10. MeNH 2

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