Page 158 - 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

IR-9.2 D E S C R I B I N G T H E C O N S T I T U T I O N O F C O O R D I N A T I O N
C O M P O U N D S

IR-9.2.1 General

Three main methods are available for describing the constitution of compounds: o ne can
draw structures, write names or write formulae. A d rawn structure contains information
about the structural components o f t he molecule as well as their stereochemical relationships.
Unfortunately, such structures a re not usually suitable f or inclusion in text. Names and
formulae are therefore used to describe t he constitution of a c ompound.
The name o f a c oordination c ompound provides detailed information about the
structural c omponents p resent. H owever, it is important that the name can be easily
interpreted unambiguously. For that reason, there should be rules that define how the name
is constructed. The f ollowing sections detail these rules and provide examples of their use.

For complicated structures the
Identify central atom(s) Section IR-9.1.2.3 name is easier to form if more
central atoms are chosen,
see Section IR-9.2.5.

Identify ligands Sections IR-9.1.2.4
and IR-9.1.2.10

Examples are given
Name ligands Section IR-9.2.2.3 in Tables VII and IX.
Anionic ligands require
special endings.

Specify coordination mode The κ convention is generally applicable
for each ligand
Section IR-9.2.4 (Sections IR-9.2.4.2 and IR-10.2.3.3).
- s pecify donor atom(s) Note that η is used when contiguous
- s pecify central atom(s) atoms are coordinated.

Order ligands and Sections IR-9.2.2.1 Ligand names are ordered alphabetically.
central atom(s) and IR-9.2.5.1 Central atom names are ordered according
to their position in Table VI.

Identify coordination Most structures will deviate
geometry and select Section IR-9.3.2 from ideal polyhedra.
polyhedral symbol The closest should be chosen.

Describe relative Section IR-9.3.3 CIP priority is used.
configuration

Determine absolute Section IR-9.3.4
configuration
Figure IR–9.1 Stepwise procedure for naming coordination compounds.

149