Page 28 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

IR-2.2 G R A M M A R

Examples:
12. [Co(NH 3 ) 6 ][Cr(CN) 6 ] ( comprising the ions [Co(NH 3 ) 6 ] 3þ and [Cr(CN) 6 ] )
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13. [Co(NH 3 ) 6 ] 2 [Pt(CN) 4 ] 3 (comprising the ions [Co(NH 3 ) 6 ] 3þ and [Pt(CN) 4 ] )

(d) To enclose structural formulae.

Example:
14. +

Mo(CO) 3

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[Mo(Z -C 7 H 7 )(CO) 3 ] þ

(e) In solid-state chemistry, to indicate an atom or a g roup of atoms in an octahedral site.
(See Section IR-11.4.3.)

Example:

15. (Mg)[Cr 2 ]O 4
(f) In specifically labelled compounds (see also Section II-2.4.2.2 of Ref. 2).

Example:
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16. H 2 [ N]NH 2

Note that this distinguishes the specifically labelled compound from the isotopically
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substituted compound H 2 NNH 2 .
(g) In selectively labelled compounds (see also Section II-2.4.3.2 of Ref. 2).

Example:
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17. [ O, P]H 3 PO 4

(h) To indicate repeating units in chain compounds.

Example:

18. SiH 3 [SiH 2 ] 8 SiH 3

IR-2.2.2.2 Use in names
Square brackets are used in names in the following ways.

(a) In specifically and selectively labelled compounds the nuclide symbol is placed in square
brackets b efore t he name of the part of the compound that is isotopically m odified.

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