Question

The correct IUPAC name of $[Co{{(N{{O}_{2}})}_{3}}{{(N{{H}_{3}})}_{3}}]$ is:
(a) Triammine Trinitro cobalt (III)
(b) trinitrotriammine cobalt (III)
(c) trinitrotriammine cobalt (III) ion
(d) trinitrotriammine cobaltate (III)

Answer 1

For writing the IUPAC name of the given coordination complex, first you should know about its IUPAC naming rule properly and then you are easily able to write its IUPAC name. now answer the given statement.

Complete step by step answer:
The IUPAC stands for the International Union of Pure and Applied Chemistry and it is the method that is used for the naming of the organic or inorganic compounds and the compounds are known by their IUPAC naming all over.
The above given compound is a coordination compound and for writing the names of the coordination compounds, there are certain rules which are as follows;
1. First of all, write the symbol of the central metal atom followed by the anionic ligands or neutral ligand and finally the cationic ligands.
2. Ligands are named alphabetically.
3. Name of the ligand is written first and then the central metal atom.
4. The naming of the ligands of some of the ligands is as;
$\begin{aligned} & F'=florido\text{ } \\\ & Cl'=chlorido \\\ & Br'=bromido \\\ & OH'=hydroxo \\\ & C{{H}_{3}}COO'=acetato \\\ & SC{{N}^{-}}'=thiocyanato \\\ & NO_{2}^{'}=nitrito \\\ & CN'=cyano \\\ \end{aligned}$
5. To indicate the number of ligands:
In simple compounds: bi for two, tri for three, tetra for four, penta for five etc.
In complex compounds: bis for two, tris for three etc.
6. If the complex is anionic, then end the name of the metal with ate. And in case of cationic complex, there is no specific ending.
7. Oxidation state of the central metal is expressed in roman numerals.

Now considering the statement;
So, keeping in mind the above given rules for writing the IUPAC name of the coordination compound, the IUPAC name of the given complex $[Co{{(N{{O}_{2}})}_{3}}{{(N{{H}_{3}})}_{3}}]$ is as,
In this, there are two ligands i.e. $N{{O}_{2}}$ and $N{{H}_{3}}$ and Co is the central metal and oxidation state of cobalt in this is $+3$.
So, thus the IUPAC name of the complex $[Co{{(N{{O}_{2}})}_{3}}{{(N{{H}_{3}})}_{3}}]$ is Triammine Trinitro cobalt (III). The correct answer is option “A” .

Note: If bridging groups are present in the coordination compound i.e. the ligands which act as bridge between the two metal atoms, $\mu$ is written before the name of the ligand as;

So, the IUPAC name of the complex is as: triamine cobalt(III)$\mu$-amido$\mu$-nitrito-N tetraamine cobalt (III).