The IUPAC name of `K_2[Cr(CN)_2O_2(O)_2(NH_3)]` is

Options

A. potassium amminedicyanodioxoperoxo chromate (VI)
B. potassium ammenecyanoperoxodioxo chromate(IV)
C. potassium amminecyanoperoxodioxo chromium (IV)
D. potassium amminecyanoperoxodloxo chromium (IV)

Answer

To determine the IUPAC name of the coordination compound \( K_2[Cr(CN)_2O_2(O)_2(NH_3)] \), we will follow a systematic approach. Here’s the step-by-step breakdown:

### Step 1: Identify the Components
The coordination compound consists of:
- Cation: \( K^+ \)
- Anionic complex: \( [Cr(CN)_2O_2(O)_2(NH_3)]^{2-} \)

### Step 2: Name the Cation
The cation is potassium, which is simply named as "potassium".

### Step 3: Identify and Name the Ligands
In the anionic complex, we have the following ligands:
- \( CN^- \) (cyanide) - named as "cyano"
- \( O_2^{2-} \) (peroxide) - named as "peroxo"
- \( NH_3 \) (ammonia) - named as "ammine"

### Step 4: Arrange the Ligands Alphabetically
When naming the ligands, we arrange them in alphabetical order based on their names:
1. Ammine (from \( NH_3 \))
2. Cyano (from \( CN^- \))
3. Peroxo (from \( O_2^{2-} \))

### Step 5: Indicate the Number of Each Ligand
We also need to indicate the number of each ligand:
- 2 cyano ligands: "dicyano"
- 2 oxo ligands: "di-oxo"
- 2 peroxo ligands: "di-peroxo"

### Step 6: Name the Metal and its Oxidation State
The metal in the complex is chromium (Cr). We need to determine its oxidation state:
- Let the oxidation state of Cr be \( x \).
- The total charge from the ligands:
- 2 cyano: \( 2 \times (-1) = -2 \)
- 2 oxo: \( 2 \times (-2) = -4 \)
- 2 peroxo: \( 2 \times (-1) = -2 \)
- Ammonia is neutral.

The overall charge of the complex is -2, so we set up the equation:
\[ x - 2 - 4 - 2 = -2 \]
\[ x - 8 = -2 \]
\[ x = +6 \]

Thus, the oxidation state of chromium is +6, and we denote it as "chromate".

### Step 7: Combine All Parts
Now we can combine all the parts to form the complete IUPAC name:
- Cation: Potassium
- Ligands: diammine, dicyano, di-oxo, di-peroxo
- Metal: chromium
- Oxidation state: (VI)

### Final IUPAC Name
Putting it all together, the IUPAC name of the compound \( K_2[Cr(CN)_2O_2(O)_2(NH_3)] \) is:
**Potassium diammine dicyano di-oxo di-peroxo chromate(VI)**