Complex ion `[FeN_(3)(O_(2))(SCN)_(4)]^(4-)` is named as : (coordination number of central metal ion in complex is six )

Options

A. azidosuperoxideotetrathiocyanato-S-ferrate(II)
B. azidodioxyggentetrathioxyanatoferrate (III)
C. azidoperoxidotetrathiocyanato-S-ferrate(II)
D. azidodioxidotetrathioxyanato-S-ferrate (III)

Explanation

To name the complex ion \([FeN_3(O_2)(SCN)_4]^{4-}\), we need to follow a systematic approach. Here’s a step-by-step breakdown of the solution:

### Step 1: Identify the Components of the Complex
The complex ion consists of:
- \(Fe\) (Iron) as the central metal ion.
- \(N_3\) (Azide ion) from \(NaN_3\).
- \(O_2\) (Dioxygen or Peroxide).
- \(SCN\) (Thiocyanate ion) with sulfur as the donor atom.

### Step 2: Determine the Oxidation State of Iron
The overall charge of the complex is \(-4\). We need to calculate the oxidation state of iron (\(Fe\)) in the complex.

Let’s denote the oxidation state of \(Fe\) as \(x\).
- The charge contribution from \(N_3\) is \(-3\) (since \(N_3^{3-}\)).
- The charge from \(O_2\) will depend on whether it is considered as \(O_2^{2-}\) (peroxide) or \(O_2^{2-}\) (superoxide).
- The charge contribution from \(4\) thiocyanate ions (\(SCN\)) is \(-4\) (since \(SCN^{-}\) contributes \(-1\) each).

The equation for the overall charge is:
\[ x + (-3) + (-4) = -4 \]
Solving this gives:
\[ x - 7 = -4 \implies x = +3 \]
Thus, the oxidation state of \(Fe\) is \(+3\).

### Step 3: Naming the Ligands
- The azide ion \(N_3^{-}\) is named as "azido".
- The dioxygen \(O_2\) can be named as "dioxido" or "peroxido" depending on its charge. Since we determined it to be \(O_2^{2-}\), we will use the term "peroxido".
- The thiocyanate ion \(SCN^{-}\) is named as "thiocyanato".

### Step 4: Assemble the Name
When naming coordination compounds, we list the ligands in alphabetical order, followed by the name of the metal with its oxidation state in Roman numerals.

The order of ligands is:
1. Azido (from \(N_3\))
2. Peroxido (from \(O_2\))
3. Thiocyanato (from \(SCN\))

Thus, the name of the complex will be:
- "Tetraazido" for \(N_3\) (4 azido ligands)
- "Dioxido" for \(O_2\) (1 dioxygen ligand)
- "Tetrathiocyanato" for \(SCN\) (4 thiocyanate ligands)

Finally, we add the name of the metal with its oxidation state:
- "Iron(III)" for \(Fe^{3+}\)

### Final Name
Putting it all together, the name of the complex ion \([FeN_3(O_2)(SCN)_4]^{4-}\) is:
**Tetraazido dioxido tetrathiocyanato iron(III)**