Page 174 - 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

Example:
5. 3+
H N 2 NH 3 O
3
H N Co O
3
H 2
HO OH C O
3 N OH
H N Co O 1 2
3
H N NH 3 Cr
3
N O
O
O
O

3
2
3
hexaammine-2k N,3k N-aqua-1kO-{m 3 -(ethane-1,2-diyldinitrilo-1k N,N )-
0
0
2
1
3
4
4
3
4
tetraacetato-1k O ,O ,O :2kO :3kO }-di-m-hydroxido-2:3k O-
chromiumdicobalt(3þ)
0
0
0
0
In this name, the obvious numbering (1,1 ,2,2 ,3,3 ,4,4 ) o f t he oxygen ligating atoms of the
four carboxylate groups is tacitly assumed.
IR-9.2.5.3 Metal–metal bonding
Metal–metal bonding or, more generally, bonding between c entral atoms in complexes, may
be indicated in names by placing italicized a tomic s ymbols of the appropriate central atoms,
separated by an ‘em’ dash and enclosed in parentheses, after the list of central atom names
and before the ionic charge. The central atom element symbols are placed in the same order
as the central atoms appear in the name (i.e. according to Table VI, with the first element
reached when f ollowing the arrow being placed last). The n umber of such bonds is indicated
by an arabic numeral placed before the first element symbol and separated from it by a
space. For the purpose of nomenclature, no distinction is made b etween d ifferent bond
orders. If there is more than one central atom of an element present in the structure, a nd it is
necessary t o i ndicate which of them is involved in the bond in question (because they are
inequivalent), the central atom locant (see Section IR 9.2.5.6) can be placed as a s uperscript
immediately after the element symbol, as shown i n E xample 4.

Examples:

1.
1 2
2
½Cl 4 ReReCl 4
4
4
octachlorido-lk Cl,2k Cl-dirhenate(Re—Re)(2 )
2.
1 2
½ðOCÞ 5 ReCoðCOÞ 4
4
5
nonacarbonyl-lk C,2k C-rheniumcobalt(Re—Co)
3.
Cs 3 [Re 3 Cl 12 ]
caesium dodecachlorido-triangulo-trirhenate(3 Re—Re)(3 )

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