Page 41 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

G R A M M A R I R-2.8

(d) To designate the mass number and/or the atomic n umber of nuclides represented by their
symbols. T he mass number is written as a l eft superscript, and the atomic number as a l eft
subscript.

Examples:

9. 18 8 O
3
10. H
1
(e) As a r ight superscript to the symbol Z, t o i ndicate the hapticity of a l igand (see Sections
IR-9.2.4.3 and IR-10.2.5.1). As a r ight subscript to the symbol m, t o i ndicate the bridging
multiplicity of a l igand (see Section IR-9.2.5.2).

Example:
5
11. [{Ni(Z -C 5 H 5 )} 3 (m 3 -CO) 2 ]
Arabic n umerals are also used as locants in names (see Section IR-2.14.2), and in the
following ways.

(a) To indicate the number of metal–metal bonds in polynuclear compounds.

Example:
12. O
C
Ni
Ni
Ni
C
O

di-m 3 -carbonyl-cyclo-tris(cyclopentadienylnickel)(3 Ni—Ni)

(b) To indicate charge.

Examples:
13. [CoCl(NH 3 ) 5 ] 2þ pentaamminechloridocobalt(2þ)
14. [AlCl 4 ] tetrachloridoaluminate(1 )

Note that the number ‘1’ must be included i n o rder to avoid a mbiguity i n r elation to symbols
for optical rotation [see Section IR-2.2.3.1(j)].

(c) As a r ight subscript to the symbol m, t o i ndicate b ridging multiplicity of a l igand (see
Section IR-9.2.5.2).

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