Question

Write a short note on IUPAC system of nomenclature of coordination compounds.

Hint:

Always name ligands first (alphabetical order), then the central atom with oxidation state, and finally the counter ion.

Answer 1

Step 1: Rules of IUPAC nomenclature.
The IUPAC system provides a standard way of naming coordination compounds. The rules include: \begin{enumerate} \item
Name of cation is written before anion.
For example: [Co(NH$_3$)$_6$]Cl$_3$ is named as hexaamminecobalt(III) chloride. \item
Ligands are named first, followed by the central atom.
Ligands are named in alphabetical order irrespective of charge. \item
Prefixes are used for number of ligands.
Mono-, di-, tri-, etc. are used. For complex ligands, bis-, tris-, tetrakis- are used. \item
Oxidation state of the central metal ion is shown in Roman numerals.
Example: [Fe(CN)$_6$]$^{4-}$ → hexacyanoferrate(II). \item
Anionic complexes end with -ate.
Example: [PtCl$_6$]$^{2-}$ → hexachloroplatinate(IV). \end{enumerate} Step 2: Example.
For [Cr(H$_2$O)$_4$Cl$_2$]Cl: Name is tetraaquadichlorochromium(III) chloride. Conclusion:
The IUPAC nomenclature system ensures clarity and uniformity in naming coordination compounds by following systematic rules.