Page 31 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

G R A M M A R I R-2.2

(g) In the Kro ¨ger–Vink notation (see Section IR-11.4), to indicate a c omplex d efect.

Example:
13. (Cr Mg V Mg Cr Mg ) x

(h) For crystalline substances, to indicate the type of crystal formed (see Chapter I R-11).

Examples:
14. ZnS(c)

15. AuCd (CsCl type)

(i) To enclose a s ymbol representing the state of aggregation of a c hemical species.

Example:
16. HCl(g) hydrogen chloride in the gaseous state

(j) In optically a ctive compounds, to enclose the signs o f r otation.

Example:

17. (þ) 589 -[Co(en) 3 ]Cl 3

(k) To enclose stereodescriptors, such as chirality descriptors and configuration indexes
(see Section IR-9.3.3.2).

Examples:

18. (2R,3S)-SiH 2 ClSiHClSiHClSiH 2 SiH 3
19. (OC-6-22)-[Co(NH 3 ) 3 (NO 2 ) 3 ]

(l) In polymers, the repeating unit is enclosed in strike-through parentheses, with the dash
superimposed on the parentheses representing the bond. 3

Example:

20. ðS Þ n

IR-2.2.3.2 Use in names

Parentheses are used in names in the following ways.
(a) To enclose substituent g roup or ligand names in order to avoid ambiguity, for example if
the substituent g roup or ligand names contain multiplicative prefixes, such as (dioxido) or
(triphosphato), o r i f s ubstitution patterns would otherwise n ot be unambiguously specified,
or if the substituent g roup or ligand name c ontains n umerical or letter descriptors. It may be
necessary t o u se different enclosing marks i f t he ligand names or substituent groups
themselves include parentheses, cf. t he nesting rule o f S ection IR-2.2.1.

22