Page 85 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

C O M P O S I T I O N A L N O M E N C L A T U R E I R-5.4

4. ClOF or OClF c hlorine oxygen fluoride o r o xygen chloride
fluoride

5. CuK 5 Sb 2 or K 5 CuSb 2 copper pentapotassium diantimonide,
or pentapotassium cupride diantimonide

Note from these e xamples that the order of any two elements in the name depends o n t he
arbitrary d ivision of elements into electropositive and electronegative constituents. (The
same applies to the order of the element symbols in the formulae as illustrated i n S ection
IR-4.4.3.4.) Additive names representing the actual structure of the compounds in Examples
3 a nd 4 ( FArH and FClO, respectively) are given in Section IR-7.2.
In some c ases, the use of substitutive or additive nomenclature for naming an ion is not
possible o r d esirable because of the lack of structural i nformation. In such cases, it may be
best to give a s toichiometric name and add the charge number. Parentheses are needed to
make it clear that the charge number denotes the overall charge of the ion.

Example:

þ
6. O 2 Cl 2 (dioxygen dichloride)(1þ)

When names of polyatomic ions occur as constituents in a g eneralized s toichiometric
name, a c ertain a mount of structural information is often implied by the name.

Example:

7. NaNH 4 [HPO 4 ] a mmonium sodium hydrogenphosphate

IR-5.4.2 Indication of proportions of constituents

IR-5.4.2.1 Use of multiplicative prefixes
The proportions of the constituents, be they monoatomic or polyatomic, may be indicated in
generalized stoichiometric names by multiplicative prefixes, as was the case for the
constituents of binary compounds (Section IR-5.2).

Examples:

disodium trioxidocarbonate, or sodium carbonate
1. Na 2 CO 3
2. K 4 [Fe(CN) 6 ] t etrapotassium hexacyanidoferrate
3. PCl 3 O p hosphorus trichloride oxide
magnesium potassium trichloride
4. KMgCl 3
When the name of the constituent i tself starts with a m ultiplicative prefix (as in disulfate,
dichromate, triphosphate, tetraborate, etc.), or when ambiguity could otherwise a rise,
the alternative multiplicative prefixes ‘ bis’, ‘tris’, ‘tetrakis’, ‘pentakis’, etc. (Table IV) are
used and the name of the group acted upon by the alternative prefix is placed in parentheses.

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