Question

What is the IUPAC name of ${{K}_{2}}\left[ PtC{{l}_{6}} \right]$?
(A) Potassium hexachloro platinum
(B) Potassium hexachloro platinum (IV)
(C) Potassium hexa chloro platinate (IV)
(D) Dipotassium hexa chloro platinum

Answer 1

The IUPAC name for the complex compounds has a specific pattern and contains the word root of all the elements comprising the complex compound.
Especially while naming the same, a quick check is necessary to know that the central metal is acting as an anion or cation in the complex part.

Complete step by step solution:
Let us first understand the coordination complex and the procedure to name any complex before we move towards the given data.
Coordination complex –
Coordination compounds are any class of substances with chemical structures which have a central metal atom surrounded by ligands (nonmetal atoms or groups of atoms) joined by a chemical bond.
The central atom is called the coordination centre.
Ligands or complexing agents is an array of bound molecules or ions.
Coordination complexes are mostly metal-containing compounds, those are transition metals.
The basic procedure for naming a complex is as follows;
1. While naming a complex ion, the ligands are named prior to the metal ion.
2. The ligands’ names are given in alphabetical order. Numerical prefixes do not affect the order.
- Monodentate ligands receive di-, tri-, tetra-, penta-, or hexa- as prefix according to their number of occurrences.
- Multiple occurring polydentate ligands receive bis-, tris-, tetrakis-, etc.
- Anions end in o. this replaces the final ‘e’ when the anion ends with ‘-ide’, ‘-ate’ or ‘-ite’, example- chloride becomes chlorido and sulphate becomes sulphato.
- Neutral ligands are given their common name, with some exceptions: $N{{H}_{3}}$ becomes amine, ${{H}_{2}}O$ becomes aqua or aquo, $CO$ becomes carbonyl, $NO$ becomes nitrosyl.
3. Write the name of the central atom/ion. The central atom’s name will end in ‘-ate’, if the central atom is an anion. Except for mercury, other atoms will get their respective Latin name.
4. The oxidation state of the central atom is to be specified enclosed in parentheses. Those should be in roman numerals.
5. Name of the cation should be preceded by the name of the anion.
Illustration-
The name of the counter ion - potassium.
The name of the complex ion - platinate (IV) as it contains platinum.
The oxidation number of platinum should be determined by charge balance. It will be hexa chloro as it contains 6 $C{{l}^{-}}$.
Combining we get, the name of the negative ion is hexachloroplatinate(IV).
So, the IUPAC name of the compound is potassium hexachloroplatinate(IV).

Therefore, option (C) is correct.

Note: Potassium hexachloroplatinate(IV) has,
Standard formula- ${{K}_{2}}PtC{{l}_{6}}$
Alphabetic formula- $C{{l}_{6}}{{K}_{2}}Pt$
Published formula- ${{K}_{2}}\left[ PtC{{l}_{6}} \right]$