Phosphinic acid nomenclature

For a number 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 in all cases in Chapter IR-8. Examples are phosphinous acid, bromic acid and peroxydisulfuric acid. (Some of these names were absent from Ref. 11.)... 

Names of trivalent and pentavalent acids end in ous and ic , respectively. The overlap of organic and inorganic nomenclature should be noted. Esters of phosphonous and phosphinous acids are named phosphonites, HP (0R)2 and phosphinites H2P (OR), respectively. 

Compounds containing a free acid function present a nomenclature problem since they can be regarded as derivatives of phosphonous acids (phosphonites), or of phosphinic acid (primary phos-phinates). The free acids have the phosphinic form whereas the amides are phosphonites (6.203). 

The nomenclature of tervalent phosphorus acid derivatives is difficult, and the literature abounds with ambiguous or misleading names. The lUPAC rules allow three methods to name the compounds (i) as substitution products of phosphine (ii) as derivatives of the parent acid or (iii) as coordination compounds of phosphorus. Of these, only the first two methods are in common use, and Table 1 gives the names of representative examples of compounds according to (i) and (ii), with the name which will be used in this chapter underlined. 

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