Page 135 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

I N O R G A N I C A C I D S A N D D E R I V A T I V E S IR-8.2

Examples:
phenylarsonic acid
4. PhAsO(OH) 2
5. EtAsCl(OH)S ethylarsonochloridothioic O-acid

The name i n E xample 4 r egards the compound as derived from arsonic acid, by substitution
of a p henyl group for the hydrogen atom bound directly to arsenic. The name in Example 5,
in addition to the hydrogen substitution, involves functional replacement nomenclature
(Section IR-8.6).
Note that there is one general case where the word ‘ acid’ may appear in a f ully
systematic name of an inorganic compound, namely when substitutive nomenclature is
used and prescribes a s uffix for the highest ranking substituent group which ends with the
word ‘acid’.
Consider the polythionic acids, H 2 S n O 6 ¼ [(HO)(O) 2 SS n 2 S(O) 2 (OH)] ( n $ 2), which
have the common names dithionic acid, trithionic acid, tetrathionic a cid, etc. T hey may be
named systematically using additive nomenclature, as shown in Table IR-8.1. F or n $ 3,
they may also be named substitutively on the basis of the central (poly)sulfane skeleton, as
exemplified below.
Examples:

6. H 2 S 3 O 6 ¼ [(HO)(O) 2 SSS(O) 2 (OH)] sulfanedisulfonic acid
7. H 2 S 4 O 6 ¼ [(HO)(O) 2 SSSS(O) 2 (OH)] disulfanedisulfonic acid

IR-8.2 G E N E R A L P R I N C I P L E S F O R S Y S T E M A T I C N A M I N G O F A C I D S

Molecular compounds and ions commonly regarded as inorganic a cids are treated no
differently than other molecular species when constructing systematic names.
The most easily applied general principle for systematic naming is that of additive
nomenclature, exemplified in Section IR-8.3. A s m entioned in Section IR-8.1, s ubstitutive
nomenclature could a lso b e g enerally applied. However, this is not further elaborated here.
Sections IR-8.4 and IR-8.5 describe hydrogen names, which are related to additive
names and only needed i n s pecial cases.
The method called ‘acid nomenclature’ in Section I-9.6 o f R ef. 2 i s l ittle used and not
needed. Its use is therefore no longer recommended.

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