Red_Book_2005

IR-1.6
the rule stated above, these are now fluorido, chlorido, bromido, iodido, hydroxido, hydrido,
cyanido, oxido, etc. In particular, thio is now reserved for functional replacement
nomenclature (see Section IR-8.6), and the ligand S 2 is named sulfido.
In anumber of cases the names of (formally) anionic ligands have changed asaresult of
modifications to the nomenclature of the anions themselves (see Section IR-1.6.2). For
example, the ligand HNNH is now named hydrazine-1,2-diido (Example 3in Section
IR-1.6.2), and HNCO * was (hydridonitrido)oxidocarbonate( * 1 )inRef. 22 but is now
named (hydridonitrato)oxidocarbonate( * 1 ).
Particular attention has been given to providing the correct names and endings for
organic ligands. Thus, with reference to Examples 4 and 5 in Section IR-1.6.2,
methanaminido is now used rather than methaminato, and aporphyrin ligand is named
porphyrin-21,23-diido rather than the name porphyrinato(2)(which is used in Ref. 11).
The systematic organic ligand names given inTable VII are now in accord with anion
names derived by the rules of Ref. 21. In anumber of casesthey differ from the names given
as systematic in Ref. 11.
IR-1.6.5 Formulae for (formal) coordination entities
In the formulae for coordination entities, ligands are now ordered alphabetically according
to the abbreviation or formula used for the ligand, irrespective of charge (Sections IR-4.4.3.2
and IR-9.2.3.1).
In Ref. 11, charged ligands were cited before neutral ligands. Thus, two ordering
principles were in use for no obvious reason other than tradition, and the person devising the
formula needed todecide whether aparticular ligand was charged. Such adecision is not
always straightforward.
Thus, for example, the recommended formula for the anion of Zeise’s salt is now [Pt(Z 2 -
C 2 H 4 )Cl3 ] whereas in Ref. 11 it was [PtCl3 ( Z 2 -C2 H 4 )] because chloride is anionic.
IR-1.6.6 Additive names of polynuclear entities
The system developed in Ref. 11 for additive names of dinuclear and polynuclear entities
has been clarified and to some extent changed for reasons of consistency: the order of
citation ofcentral atoms in names is now always the order in which they appear in Table VI,
the element occurring later being cited first (see Sections IR-7.3.2 and IR-9.2.5.6).
The system can be used for polynuclear entities with any central atoms. In this system,
the order of the central atoms in the name reflects the order in which they are assigned
locants to be used in the kappa convention (Section IR-9.2.4.2) for specifying which ligator
atoms coordinate to which central atoms. The atom symbols used at the end of the name to
indicate metal-metal bonding are similarly ordered. Thus, for example, [(CO) 5 ReCo(CO) 4 ]
is now named nonacarbonyl-1k 5 C ,2k 4 C -rheniumcobalt(Re—Co) rather than nonacarbonyl-
1 k 5 C ,2k 4 C -cobaltrhenium(Co—Re) (as in Ref. 11).
IR-1.6.7 Names of inorganic acids
GENERALAIMS,FUNCTIONS ANDMETHODS
The names of inorganic acids are dealt with separately in Chapter IR-8.
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