Page 35 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

G R A M M A R I R-2.3

They can also indicate the sign of optical rotation in the formula o r n ame of an optically
active compound.

Example:

5. (þ) 589 -[Co(en) 3 ] 3þ (þ) 589 -tris(ethane-1,2-diamine)cobalt(3þ)

IR-2.3.3 ‘Em’ dashes
‘Em’ dashes a re used in formulae only when the formulae are structural. (The less precise
term ‘long dashes’ was used in Ref. 4.)
In names, ‘ em’ dashes are used in two ways.

(a) To indicate m etal–metal bonds in polynuclear compounds. T hey separate the italicized
symbols of the bond partners which are contained in parentheses at the end of the name.
Example:

1. [Mn 2 (CO) 10 ] b is(pentacarbonylmanganese)(Mn—Mn)

(b) To separate the individual constituents in names of (formal) addition compounds.

Examples:

2. 3CdSO 4 ·8H 2 O c admium s ulfate—water (3/8)
3. 2CHCl 3 ·4H 2 S·9H 2 O c hloroform— h ydrogen sulfide—water (2/4/9)

IR-2.3.4 Special bond indicators for line formulae
——
The structural symbols | | a nd | —— | m ay be used in line formulae to indicate bonds
between n on-adjacent atom symbols.

Examples:
1. Me Me
P
Ni
S
5
[Ni(S=PMe )(η -C H )]
5 5
2
2.
Ph P
2
(OC) Mn Mo(CO) 3
4
5
[(CO) MnMo(CO) (η -C H PPh )]
2
5 4
3
4
26