Page 55 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

O R G A N O M E T A L L I C C O M P O U N D S IR-10.4

nomenclature is fully described in Section IR-6.2.4.3 and in Section P-22.2 of Ref. 3 a nd
will not be elaborated further here.
Sections P-68 and P-69 of Ref. 3 o ffer a m ore c omprehensive treatment of the
nomenclature of organic compounds containing the elements of groups 13–16.

IR-10.4 O R D E R I N G O F C E N T R A L A T O M S I N P O L Y N U C L E A R
O R G A N O M E T A L L I C C O M P O U N D S

When an organometallic compound contains two or more different metal atoms, a c hoice
must be made to provide the basis of the name. It is thus convenient to classify the possible
central atoms as belonging to either (i) the elements of groups 1–12 (whose compounds
are named according to the additive system of nomenclature) or (ii) the elements of groups
13–16 (whose compounds are named according to the substitutive system).

IR-10.4.1 Central atoms f rom groups 1–12 only

If both or all potential central atoms belong to class (i), then the compound is named
additively using the methodology described in Section IR-9.2.5, including the rules given
there for ordering the central atoms. Ferrocenyllithium (ferrocenyl, s ee Section IR-10.2.6)
could thus be systematically named:

5
5
1
(2Z -cyclopentadienyl)(2Z -cyclopenta-2,4-dien-1-yl-1kC )lithiumiron,
a n ame which also illustrates t he use of the k and Z conventions. Further examples in
which both or all central atoms belong to class (i) are given i n S ections IR-10.2.3.4,
IR-10.2.3.5 and IR-10.2.5.1.

IR-10.4.2 Central atoms f rom both groups 1–12 and g roups 1 3–16
If at least one possible central atom belongs to class (i) and one or more others to class (ii),
then the compound is named additively u sing t he metal atom(s) of class (i) as central
atom(s). The remaining atoms of the complex a re named as ligands by rules already
presented (Sections IR-9.1, IR-9.2 and IR-10.2.1 to IR-10.2.5).

Examples:
1. [Li(GePh 3 )] (triphenylgermyl)lithium

2. (Me 3 Si) 3 CMgC(SiMe 3 ) 3
bis[tris(trimethylsilyl)methyl]magnesium
3. [Mo(CO) 5 (¼Sn{CH(SiMe 3 ) 2 } 2 )]
2
{bis[bis(trimethylsilyl)methyl]-l -stannylidene}pentacarbonylmolybdenum
4.

4 1
Ph Sb HgPh
2
[4-(diphenylstibanyl)phenyl](phenyl)mercury

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