Question

What is the IUPAC name of [Co(CN)6]³- and [ Cr(H20)6]³+​

Answer 1

IUPAC NAMING OF CO-ORDIANTION COMPOUNDS

In IUPAC nomenclature, the basic rules are :-

• The name of ligend is mentioned before the name of central metal ion.

• If the co-ordination sphere is negatively charged, the name of central metal ion ends with the suffix 'ate' . Sc - Scandate , Cr - Chromate , Co - Cobaltate

• The name of negatively charged li ends with 'ido'

For example :- Chlorido, Bromido, Iodido

• The oxidation state of central metal ion is mention inside a bracket.

• For a similar ligend attached more than one time, we use the prefix :- Di, Tri , Tetra, Penta , Hexa .

• Ligend are arranged in alphabetical order of their names but the prefix like Di , Tri etc. are not considered.

• For bidentate ligend ,we use bis . For example :- bis(ethane-1,2-diamine)

* Ligend is not the correct spelling,it is due to some technical issues

SOLUTIONS :-

Considering above rules, The IUPAC name of the complexes will be :-

[Co(CN)6] ³- => Hexacyanocobalate(iii) ion

[Cr(H20)6]³+ => HexaaquaChromium(iii) ion