Page 96 - Nomenclature of Inorganic Chemistry (IUPAC Recommendations 2005)

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

Examples:
1.
1 2 3 4
H 5 SSSH 4 SH
6
6
6
6
1l ,3l -tetrasulfane (not 2l ,4l )
2.
1 2 3 4 5
HSSH 4 SH 4 SH 2 SH
4
6
6
6
6
4
2l ,3l ,4l -pentasulfane (not 2l ,3l ,4l )
3.
H 4 PPH 3 PH 3 PH 4
5 5 5 5
ll ,2l ,3l ,4l -tetraphosphane
4.
HPbPbPbH
2
2
2
1l ,2l ,3l -triplumbane
IR-6.2.2.3 Unsaturated homonuclear acyclic h ydrides
Chains containing unsaturation are accommodated in substitutive nomenclature by the
methods used with alkenes and alkynes (see Section P-31.1 of Ref. 1), i.e. the name of the
corresponding saturated chain hydride is modified by replacing the ‘ane’ ending with ‘ene’ in
the case of a d ouble b ond and ‘yne’ in the case of a t riple bond. If there is one of each, the ending
becomes ‘en’ . . .‘yne’ with appropriate locants; ‘diene’ is used when there are two double
bonds, and so on. In each case the position(s) o f u nsaturation is (are) indicated by (a) numerical
locant(s) immediately preceding the suffix(es). Locants are chosen t o b e a s l ow as possible.
Examples:
1.
HN¼NH diazene
2.
HSb¼SbH distibene
3.
1 2 3 4 5
pentaaz-2-ene (not pentaaz-3-ene)
H 2 NN¼NNHNH 2
Unsaturated acyclic hydrides are not classified as parent hydrides. B ecause of the
hierarchical rules of substitutive nomenclature, the numbering of the double and triple bonds
may not be fixed until various g roups and modifications have been numbered. (See Section
IR-6.4.9 for an example.)

IR-6.2.2.4 Homonuclear monocyclic parent hydrides

There are three main ways o f g iving p arent names to homonuclear monocyclic hydrides:

(i) by using t he Hantzsch–Widman (H–W) name (see Section IR-6.2.4.3 a nd Section
P-22.2 of Ref. 1);
(ii) by using the relevant r eplacement prefix (‘a’ term) from Table X t ogether w ith the
appropriate multiplicative p refix to indicate replacement of carbon atoms in the
corresponding carbocyclic compound name (see Section P-22.2 of Ref. 1);
(iii) by adding the prefix ‘cyclo’ to the name o f t he corresponding unbranched, unsubstituted
chain (see Sections IR-6.2.2.1 to IR-6.2.2.3 and Section P-22.2 of Ref. 1).

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