Page 133 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

IR-8 Inorganic A cids and Derivatives

C O N T E N T S

IR-8.1 Introduction and overview
IR-8.2 General p rinciples f or systematic naming of acids
IR-8.3 Additive names
IR-8.4 Hydrogen names
IR-8.5 Abbreviated hydrogen names for certain a nions
IR-8.6 Functional r eplacement names for derivatives of oxoacids
IR-8.7 References

IR-8.1 I N T R O D U C T I O N A N D O V E R V I E W

Certain inorganic a nd simple c arbon-containing compounds are commonly given non-
systematic or semi-systematic names containing the word ‘ acid’. E xamples are boric acid or
orthoboric acid, metaboric acid, phosphoric acid, diphosphoric acid, cyclo-triphosphoric
acid, catena-triphosphoric acid, dithionous acid, peroxodisulfuric acid o r p eroxydisulfuric
acid, etc. T hese names are unique i n m odern nomenclature in that, interpreted literally, t hey
describe a p articular chemical property of the compounds in question. Systematic names are
otherwise based solely on composition and structure.
All such acids may also b e g iven s tructure-based s ystematic names using p rinciples
already described in preceding chapters on substitutive and additive nomenclature, so in that
respect the ‘acid’-containing names are superfluous. Furthermore, many s pecies which
would be classified as acids based on their chemical properties are never named as such,
e.g. aqua ions such as hexaaquaaluminium(3þ), and hydrides and derivatives such as
ammonium, hydrogen sulfide ( sulfane), etc. T he term ‘acid’ is thus not used consistently.
Based on these c onsiderations, the use of the word ‘acid’ in any new name i n i norganic
nomenclature is discouraged. However, a n umber of the existing ‘acid’ names are so
commonly used (sulfuric acid, perchloric acid, etc.) t hat it would be unrealistic to suggest
replacing them altogether by systematic alternatives. Another reason to include them in the
present recommendations is that the acids in question a re used as parent structures i n t he
nomenclature of certain o rganic (i.e. carbon-containing) derivatives so that the derivative
names are directly or indirectly based on the names containing the word ‘acid’. S ee
examples below a nd Section IR-8.6.

The main purposes of this c hapter are:

(a) to show how the inorganic species commonly named as acids may be given
systematic additive names (Section IR-8.3 and Tables IR-8.1 and IR-8.2);

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