Page 125 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

A D D I T I V E N O M E N C L A T U R E IR-7.3

13. (NC)SS(CN) b is[(nitridocarbonato)sulfur](S — S),
or bis(cyanidosulfur)(S — S)
14. (NC)SS(CN) * bis[(nitridocarbonato)sulfate](S — S)( * 1 ),
or bis(cyanidosulfate)(S—S)( * 1 )
di-m-chlorido-bis(dichloridoaluminium)
15. Cl 2 Al(m-Cl) 2 AlCl 2

Note that the five c ompounds in Examples 10–14 may also easily be named as chain
compounds, as shown i n S ection IR-7.4. T he name i n E xample 14 differs from that given i n
Ref. 1 ( in which the sulfur–sulfur bond was indicated as above, but the carbon atoms were
treated as the central atoms).
The species in Examples 1 3 a nd 14 may also b e r egarded as containing a b ridging l igand,
as demonstrated in Examples 16 and 17.

Examples:

16. [NCSSCN] m-disulfanediido-bis(nitridocarbon)
17. [NCSSCN] * m-disulfanediido-bis(nitridocarbonate)( * 1 )

IR-7.3.2 Non-symmetrical dinuclear compounds

There are two types o f n on-symmetrical dinuclear compounds: ( i) those with identical
central atoms differently ligated, and (ii) those with different central atoms. In both cases
names are formed by means of the procedure described in Section IR-9.2.5, which also deals
with bridging g roups.
Priority is assigned to the central atoms as follows. For cases o f t ype (i) the central atom
carrying the greater number of alphabetically preferred ligands is numbered 1. For cases o f
type (ii) the number 1 i s a ssigned to the higher priority central element of Table VI,
whatever the ligand distribution.
In both types of compound, names are constructed i n t he usual way, b y fi rst citing the
prefixes r epresenting the ligands in alphabetical order. Each prefix representing a l igand is
followed by a h yphen, the number(s) assigned to the central atom(s) to which the ligand is
attached (see below), t he Greek letter k (kappa) (see Section IR-9.2.4.2) with a r ight super-
script denoting the number of such ligands bound t o t he central atom(s) (the number 1 b eing
omitted for a s ingle ligand), a nd the italic element symbol for the ligating atom by which
the ligand is attached to the central atom(s). This describes the ligands and their mode of
attachment. The k construction can be omitted in very simple cases ( see Examples 1–3
below) or when the distribution of the ligands on the central atoms is obvious (see Example 4
below).
The central atom names are listed after the ligand names. The multiplicative prefix ‘di’ is
used where the central atoms are the same element. Otherwise, the order of the central atom
names is obtained using Table VI. The o rder of the central atom names is reflected in the
numbering employed with the k symbols. The ending ‘ate’ is added if the dinuclear
compound is an anion, and a r adical dot may be added for radicals. In the case of two
different central atoms, the two names are cited inside parentheses and ‘ate’ is added outside
the parentheses.

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