Page 93 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

S U B S T I T U T I V E N O M E N C L A T U R E IR-6.2

IR-6.4.8 Substituted r adicals o r s ubstituent groups
IR-6.4.9 Anionic and cationic centres and radicals in a s ingle molecule or ion
IR-6.5 References

IR-6.1 I N T R O D U C T I O N

Substitutive nomenclature is a s ystem in which names are based on the names of parent
hydrides, w hich define a s tandard p opulation of hydrogen atoms attached to a s keletal structure.
Names ofderivatives ofthe parenthydridesare formed bycitingprefixes or suffixes appropriate
to the substituent g roups (or substituents) replacing the hydrogen atoms (preceded by locants
when required), joined without a b reak t o t he name of the unsubstituted parent hydride.
Substitutive nomenclature is recommended o nly for derivatives of the parent hydrides
namedinTableIR-6.1(inSectionIR-6.2.1),andderivativesofpolynuclearhydridescontaining
only these e lements (see Sections IR-6.2.2 to IR-6.2.4). The b onding numbers of the
skeletal atoms are understood to be as in Table IR-6.1 (these bonding numbers, e.g. 4 f or Si and
2 f orSe,aretermedstandard b ondingnumbers).Other b ondingnumbersmustbeindicatedbyan
appropriatedesignator(the‘l convention’,seeSectionIR-6.2.2.2 and Section P-14.1 of Ref. 1).
In general, r elevant p ractices and conventions of substitutive nomenclature as applied to
1
organic compounds are also followed here.
Constructing a s ubstitutive name generally involves the replacement of hydrogen atoms
in a p arent structure with other atoms or atom groups. Related operations, often considered
to be part of substitutive nomenclature, are skeletal replacement (Section IR-6.2.4.1) and
functional replacement in oxoacid p arents (Section IR-8.6). Note that some o perations in
parent hydride-based nomenclature are not substitutive operations (e.g. formation of cations
and anions by addition of H þ and H , r espectively, cf. S ections IR-6.4.1 and IR-6.4.5).
Names formed by the modifications of parent hydride names described in those s ections are
still considered part of substitutive nomenclature.
In most c ases, the compounds named substitutively in the present chapter may
alternatively and equally systematically be named additively ( Chapter IR-7), b ut it is
important to note that for the parent hydrides presented here such additive names cannot
be used as parent names in substitutive nomenclature.
Neutral boron hydrides are called boranes. The basic aspects of borane nomenclature
are provided in Section IR-6.2.3; more advanced aspects will be treated in a f uture IUPAC
publication.

IR-6.2 P A R E N T H Y D R I D E N A M E S

IR-6.2.1 Mononuclear parent hydrides w ith standard and non-standard bonding numbers

The mononuclear hydrides of elements of groups 13–17 of the periodic t able play a c entral
role in substitutive nomenclature. They are used as parent hydrides as indicated above with
the parent names given i n T able IR-6.1.
In cases w here the bonding number deviates from the standard n umber defined above, it
must be indicated in the hydride name b y m eans of an appropriate superscript appended to
the Greek letter l, t his symbol being separated from the name in Table IR-6.1 by a h yphen.

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