`[Fe(CN)_(5)(CO)]^(3-)` IUPAC name is

Options

A. pentacyanocarbonylferrate (II)
B. carbonylpentacyanidoferrate (II)
C. pentacyanocarbonyliron (III)
D. carbonylpentacyanoiron (III)

Explanation

To determine the IUPAC name of the coordination complex \([Fe(CN)_{5}(CO)]^{3-}\), we will follow the systematic naming rules for coordination compounds step by step.

### Step 1: Identify the Ligands
The complex contains two types of ligands:
- **Cyanide (CN)**: This is an anionic ligand with a charge of -1. Since there are five cyanide ligands, we will use the prefix "penta" to indicate the number.
- **Carbonyl (CO)**: This is a neutral ligand.

### Step 2: Name the Ligands
According to IUPAC naming conventions, we name the ligands in alphabetical order, considering the prefixes for the number of ligands:
- The ligands are named as follows:
- Carbonyl (neutral ligand)
- Penta-cyanide (for five cyanide ligands)

Since both ligands start with the letter 'C', we look at the second letter to determine the order. The second letter of "carbonyl" is 'a' and that of "cyanide" is 'y'. Therefore, "carbonyl" comes before "cyanide".

Thus, the ligands are named as:
- Carbonyl
- Penta-cyanide

### Step 3: Determine the Metal and its Oxidation State
The central metal in the complex is iron (Fe). To determine the oxidation state of iron, we can set up the following equation based on the charges:
- Let the oxidation state of iron be \(x\).
- The total charge of the complex is -3.
- The contribution from the five cyanide ligands is \(5 \times (-1) = -5\).
- The carbonyl ligand contributes 0 since it is neutral.

Setting up the equation:
\[ x + (-5) + 0 = -3 \]
\[ x - 5 = -3 \]
\[ x = +2 \]

Thus, the oxidation state of iron is +2.

### Step 4: Name the Metal
Since the complex is anionic (it has a negative charge), the name of the metal changes. Iron becomes "ferrate" when it is part of an anionic complex.

### Step 5: Combine the Names
Now we can combine the names of the ligands and the metal with the oxidation state:
- Ligands: Carbonyl, Penta-cyanide
- Metal: Ferrate
- Oxidation state: (II)

Putting it all together, the IUPAC name of the complex is:
**Carbonyl penta-cyanide ferrate(II)**

### Final Answer
**Carbonyl penta-cyanide ferrate(II)**

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