`p pi - d pi` bonding is not formed between oxygen and

Options

A. Phosphours in `P_(4)O_(10)`
B. Nitrogen in `N_(2)O_(5)`
C. Chlorine in `HClO_(4)`
D. Chlorine in anionic part of solid `Cl_(2)O_(6)`

Answer

To solve the question regarding which element does not form p pi - d pi bonding with oxygen, we need to analyze the bonding capabilities of the given options based on their electronic configurations and the presence of d orbitals.

### Step-by-Step Solution:

1. **Understanding p pi - d pi Bonding**:
- p pi - d pi bonding occurs when a p orbital from one atom overlaps with a d orbital from another atom. For this type of bonding to occur, the atom with the d orbitals must have available d orbitals (empty d orbitals) to participate in bonding.

2. **Identify the Elements**:
- The question provides options that include elements like phosphorus, nitrogen, chlorine, etc. We need to consider their ability to form p pi - d pi bonds with oxygen.

3. **Analyzing Each Option**:
- **Option A: Phosphorus (in P4O10)**:
- Phosphorus has empty d orbitals and can participate in p pi - d pi bonding with oxygen. Therefore, it can form p pi - d pi bonds.

- **Option B: Nitrogen (in N2O5)**:
- Nitrogen is a small atom with no available d orbitals. It only has s and p orbitals. Thus, nitrogen cannot form p pi - d pi bonds with oxygen.

- **Option C: Chlorine**:
- Chlorine has available d orbitals and can participate in p pi - d pi bonding with oxygen. Therefore, it can form p pi - d pi bonds.

- **Option D: Another element (not specified)**:
- If this option is also a heavier element with d orbitals, it would likely be able to form p pi - d pi bonds with oxygen.

4. **Conclusion**:
- Based on the analysis, the element that cannot form p pi - d pi bonding with oxygen is **Nitrogen (Option B)**, as it lacks the necessary d orbitals.

### Final Answer:
**Nitrogen in N2O5 does not form p pi - d pi bonding with oxygen.**