Page 21 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

G E N E R A L A I M S , F U N C T I O N S A N D M E T H O D S I R-1.6

Names described in Ref. 11 under the heading ‘acid nomenclature’, e.g. tetraoxosulfuric
acid, trioxochloric(V) acid, have been abandoned. In addition, the format of the names
described in Ref. 11 under the heading ‘hydrogen nomenclature’ has been changed s o t hat
‘hydrogen’ is always attached directly to the second p art of the name, and this part is always
in enclosing marks. The charge number at the end of the name i s t he total charge.

Examples:

1. HCrO 4 , h ydrogen(tetraoxidochromate)(1 )

þ
2. H 2 NO 3 , d ihydrogen(trioxidonitrate)(1þ)
A r estricted list of names of this type where the enclosing marks and charge number may be
omitted is given in Section IR-8.5 (hydrogencarbonate, dihydrogenphosphate and a f ew
others). ( These n ames do not differ from those i n R ef. 11.)
The main principle, however, is to use additive nomenclature for deriving systematic
names for inorganic acids. For example, the systematic name for dihydrogenphosphate,

H 2 PO 4 , i s d ihydroxidodioxidophosphate(1 ).
For a n umber of inorganic acids, used as functional parents in organic nomenclature, the
parent names used are now consistently allowed in the present recommendations, although
fully systematic additive names are also given i n a ll cases i n C hapter IR-8. Examples are
phosphinous acid, bromic acid and peroxydisulfuric a cid. ( Some o f t hese names were absent
from Ref. 11.)

IR-1.6.8 Addition compounds
The formalism for addition compounds, and other c ompounds treated as such, has been
rationalized (see Sections IR-4.4.3.5 and IR-5.5) s o a s t o r emove t he exceptional treatment
of component boron compounds and to make the construction of the name s elf-contained
rather than dependent on the formula. Thus, the double salt carnallite, when c onsidered
formally a s a n a ddition compound, is given the formula:

KCl·MgCl 2 ·6H 2 O
( formulae of compounds o rdered alphabetically, water still placed last),

and the name:

magnesium chloride—potassium chloride— w ater (1/1/6)
(names of components ordered alphabetically).

IR-1.6.9 Miscellaneous
(i) In the present recommendations the radical dot i s r egarded as optional in formulae and
names whereas in Ref. 22 the dot is not omitted in any systematic names. [For example,
*
in Ref. 22, NO is shown as NO with the name oxidonitrogen( * ).]
(ii) The order of enclosing marks (Section IR-2.2.1) has been changed f rom that in Ref. 11
in order to ensure c onsistency with Ref. 21.

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