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3 2 1 4

+3
[Co (H 2O) 6]Br 3 hexaaquacobalt (III) bromide

↑ ↑ ↑ ↑

3 2 1 4

where 1, 2, .3, 4 are the order of the components names of the coordination

complex.

The name of the complex, which has no external sphere (complex non-

electrolytes), consists of one word in which the names of the ligands and their

number and the name of the complexing agent are listed. The oxidation state of

the complexing agent is not indicated, since it is determined by the sum of ligands

charges.

For example:

+3
[Cr (H 2O) 3F 3] trifluoridetriaqua chromium

↑ ↑ ↑↑↑

5 4 321

The dissociation of coordination complexes occurs gradually: at first, the

compound dissociates into the ions of the outer sphere and the complex ion

(primary dissociation), then the complex ion dissociates into on the complexing

agent and the ligands (secondary dissociation), and the secondary dissociation is

insignificant. For example, the dissociation of the coordination complex containing

the complex anion:

+
3-
K 3[Fe(CN) 6]  3K +[Fe(CN) 6] ,
3-
-
3+
[Fe(CN) 6]  Fe + 6CN .
The dissociation of the coordination complex containing a complex cation:
2+ 2-
[Zn(NH 3) 4]SO 4  [Zn(NH 3) 4] + SO 4
2+ 2+
[Zn(NH 3) 4]  Zn + 4NH 3
The dissociation of the complex non-electrolyte:

3+
[Cr(H 2O) 3F 3]  Cr + 3H 2O + 3F -

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