Which of the following species has used both axial set of d-orbitals in hybridisation of central atom ?

Options

A. `PBr_(4)^(+)`
B. `PCl_(4)^(-)`
C. `IC l_(4)^(-)`
D. none of these

Answer

To determine which species uses both axial sets of d-orbitals in the hybridization of the central atom, we will analyze the given options step by step.

### Step 1: Understand Axial d-Orbitals
Axial d-orbitals refer to the d-orbitals that are aligned along the axes of a coordinate system. In the context of hybridization, these orbitals can participate in forming hybrid orbitals when the central atom has a coordination number that allows for their involvement.

### Step 2: Analyze Each Option
We will analyze each of the given options to determine their hybridization and whether they utilize both axial d-orbitals.

#### Option A: PBr4+
1. **Structure**: The molecular geometry of PBr4+ is tetrahedral.
2. **Hybridization**: The hybridization is sp³.
3. **d-Orbital Involvement**: Since it is sp³ hybridization, no d-orbitals are involved.

**Conclusion**: PBr4+ does not use axial d-orbitals.

#### Option B: PCl4-
1. **Structure**: The molecular geometry of PCl4- is seesaw (or distorted tetrahedral).
2. **Hybridization**: The hybridization is sp³d.
3. **d-Orbital Involvement**: Only one d-orbital is involved in this hybridization.

**Conclusion**: PCl4- does not use both axial d-orbitals.

#### Option C: ICl4-
1. **Structure**: The molecular geometry of ICl4- is square planar.
2. **Hybridization**: The hybridization is sp³d².
3. **d-Orbital Involvement**: In sp³d² hybridization, both axial d-orbitals are used.

**Conclusion**: ICl4- uses both axial d-orbitals in the hybridization of the central atom (iodine).

### Step 3: Final Answer
Based on the analysis, the species that uses both axial sets of d-orbitals in the hybridization of the central atom is **ICl4-**.

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