3.6

SECTION

3

PO

phosphoryl

SeO

seleninyl

SO

sulfinyl (thionyl)

SeO

2

selenonyl

SO

2

sulfonyl (sulfuryl)

UO

2

uranyl

S2O

5

disulfuryl

NpO

2

neptunyl†

quired to give a neutral unit

to polyatomic anions are named by adding the ending -onium to the

root

of the name of the anion

element; for example,

,

phosphonium ion; H PH4

2I , iodonium ion;

H 3 O

, oxonium ion;

CH OH,methyl3 2 oxonium ion.

Exception:

The name

ammonium is retained

for the

ammo-

ion; similarly forNHsubstituted4

nium

ions; for

example,

,

ion.

tetrafluoroammoniumNF4

Substituted ammonium ions derived from nitrogen bases with names ending in -amine receive

names formed by changing -amine into -ammonium. When known by a name not ending in -amine,

the

cation name

is formed by

adding the ending -ium

to the

name of the base (eliding the final

See Secs. 3.1.2.2 and 3.1.2.8 for naming monatomic and certain polyatomic anions. When an organic

group occurs in an inorganic compound, organic nomenclature

(q.v.)

is followed to name the organic

part.

3.1.4.1

Protonated Anions.

Ions such as

HSOare4recommended to be named hydrogensulfate

with the two words written as one following the usual practice for polyatomic anions. However, in

the Nomenclature of Organic

Chemistry,

1979 edition, hydrogen is used as a

separate word; this

practice is

followed in this Handbook.

INORGANIC CHEMISTRY

3.7

3.1.4.2

Other

Polyatomic

Anions.

Names

for other

polyatomic anions consist of the root name

of the central atom with the ending -ate

and followed by the valence of the

central atom

expressed

by its oxidation number. Atoms and groups attached to the central atom are treated as ligands in a

complex.

Examples:

[Sb(OH)

],

hexahydroxoantimonate(V);

[Fe(CN

3

,

hexacyanoferrate(III);

6

6]

[Co(NO

3

,

hexanitritocobaltate(III); [TiO(C

2O

4)2(H 2O)

2

,

oxobisoxalatodiaquatitanate(IV);

2)6]

2]

[PCl6] , hexachlorophosphate(V).

Exceptions to the use of the root name of the central atom are antimonate, bismuthate, carbonate,

cobaltate, nickelate (or niccolate), nitrate, phosphate, tungstate (or wolframate), and zincate.

3.1.4.3

Anions

of

Oxygen.

Oxygen is treated in the

same manner as other ligands with the

number of -oxo groups indicated by a suffix;

for example,

, trioxosulfate.

SO

32

The ending -ite, formerly used to denote a lower state of oxidation,

may

be retained

in

trivial

names in these cases (note Sec. 3.1.5.3 also):

AsO

3

arsenite

NOO

peroxonitrite

3

2

BrO

hypobromite

PO

3

3 phosphite*

ClO

hypochlorite

SO 32 sulfite

ClO

chlorite

S2O

2

disulfite

2

5

IO

hypoiodite

S2O

24 dithionite

NO

nitrite

S2O

2

thiosulfite

2

2

N O2

2

hyponitrite

SeO

2

selenite

2

3

However, compounds known to be double oxides in the solid state

are named as such; for

example, Cr

2CuO

4 (actually

Cr

2O 3 · CuO) is

chromium(III) copper(II)

oxide

(and

not copper chro-

mite).

3.1.4.4

Isopolyanions.

Isopolyanions are named by indicating with numerical prefixes the num-

ber of atoms of the characteristic element. It is not necessary to give the number of oxygen atoms

when the charge of the anion or the number of cations is indicated.

Examples:

Ca

3 Mo

7O 24, tricalcium 24-oxoheptamolybdate, may be shortened to tricalcium hep-

tamolybdate; the

anion,

);S O

2

2

,

disulfate(2

P);O

4

, diphos-

,MoisO7heptamolybdate(624

7

2 7

phate(V)(4

).

When

the

characteristic

element is

partially or wholly present in

a

lower

oxidation

state

than

corresponds

to

its

Periodic

Group

number,

oxidation

numbers

are

used;

for

example,

[O2HP9O

9PO 3 H]2 , dihydrogendiphosphate(III,V)(2

).

A bridging group should be indicated by adding the Greek letter

immediately before its names

and separating this from the rest of the complex by a hyphen. The atom or atoms of the characteristic

element to which the bridging atom is bonded, is indicated by numbers.

Examples:

[O3 P9S 9PO2 9O

9PO 3]5 , 1,2- -thiotriphosphate(5

)

[S3 P9O

9PS2 9O

5

)

9PS3 ] , di- -oxo-octathiotriphosphate(5

* Named for esters formed from the hypothetical acid P(OH)

3 .