The IUPAC name of [Ni(CO)4] is:

(a) Tetracarbonyl nickelete(0)

(b) Tetracarbonyl nickelete(II)

(c) Tetracarbonyl nickel(0)

(d) Tetracarbonyl nickel(II)

The IUPAC name of the compound [Ni(CO)4] is (c) Tetracarbonyl nickel(0). To understand why this is the correct choice, let’s break down the components of the compound and the naming conventions used in coordination chemistry.

Understanding the Components

The compound [Ni(CO)4] consists of a nickel (Ni) atom coordinated to four carbon monoxide (CO) ligands. In coordination complexes, the central metal atom can have different oxidation states, which are crucial for determining the correct IUPAC name.

Identifying the Oxidation State

In this case, carbon monoxide is a neutral ligand, meaning it does not contribute any charge to the overall complex. Since there are four CO ligands, they collectively contribute a charge of zero. Therefore, to maintain charge neutrality in the complex, the nickel must also have an oxidation state of zero.

Applying IUPAC Naming Conventions

When naming coordination compounds, the ligands are named first, followed by the metal. In this instance, the ligand is carbonyl (from CO), and since there are four of them, we use the prefix "tetra-" to indicate this. Thus, we have "tetracarbonyl" as the ligand name.

Combining the Names

Next, we name the metal. Since nickel is in the zero oxidation state, we denote this by using the term "nickel(0)." Therefore, the full IUPAC name of the compound is "tetracarbonyl nickel(0)." This naming reflects both the number of ligands and the oxidation state of the metal.

Why Other Options Are Incorrect

• Tetracarbonyl nickelete(II): This option incorrectly suggests that nickel is in the +2 oxidation state, which is not the case here.
• Tetracarbonyl nickel(II): Similar to the previous option, this one also implies a +2 oxidation state for nickel, which is incorrect.
• Tetracarbonyl nickelete(0): While it correctly identifies the oxidation state as zero, the term "nickelete" is not standard nomenclature in IUPAC naming.

In summary, the correct IUPAC name for [Ni(CO)4] is indeed "tetracarbonyl nickel(0)," as it accurately reflects the structure and oxidation state of the compound. Understanding these naming conventions is essential for accurately communicating the properties of coordination complexes in chemistry.