In which of following compound a `ppi - dpi` bonding is present

Options

A. Trisilylamine
B. Graphite
C. Dimethyl amine
D. Diamond

Answer

To determine which of the given compounds exhibits p-d pi bonding, we will analyze each compound in terms of its atomic structure and the presence of vacant d orbitals.

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds given are:
- A) Trisilyl amine (SiH3)3N
- B) Graphite
- C) Diamond
- D) Dimethyl amine (CH3)2NH

2. **Analyze Trisilyl Amine**:
- **Structure**: (SiH3)3N
- **Atoms Involved**: Silicon (Si), Nitrogen (N), and Hydrogen (H).
- **Electronic Configuration**:
- Si: Atomic number 14 → 1s² 2s² 2p⁶ 3s² 3p² (has vacant 3d orbitals)
- N: Atomic number 7 → 1s² 2s² 2p³ (no vacant d orbitals)
- H: Atomic number 1 → 1s¹ (only s orbital)
- **Conclusion**: Silicon can form p-d pi bonding with nitrogen due to its vacant d orbitals. **Trisilyl amine exhibits p-d pi bonding.**

3. **Analyze Graphite**:
- **Structure**: All carbon atoms.
- **Atoms Involved**: Carbon (C).
- **Electronic Configuration**: Atomic number 6 → 1s² 2s² 2p² (no vacant d orbitals).
- **Conclusion**: Since carbon does not have vacant d orbitals, graphite does not exhibit p-d pi bonding.

4. **Analyze Diamond**:
- **Structure**: All carbon atoms.
- **Atoms Involved**: Carbon (C).
- **Electronic Configuration**: Same as graphite (1s² 2s² 2p²).
- **Conclusion**: Like graphite, diamond does not have vacant d orbitals, hence it does not exhibit p-d pi bonding.

5. **Analyze Dimethyl Amine**:
- **Structure**: (CH3)2NH
- **Atoms Involved**: Nitrogen (N), Carbon (C), and Hydrogen (H).
- **Electronic Configuration**:
- N: Atomic number 7 → 1s² 2s² 2p³ (no vacant d orbitals)
- C: Atomic number 6 → 1s² 2s² 2p² (no vacant d orbitals)
- H: Atomic number 1 → 1s¹ (only s orbital)
- **Conclusion**: Both nitrogen and carbon lack vacant d orbitals, so dimethyl amine does not exhibit p-d pi bonding.

6. **Final Conclusion**:
- The only compound that exhibits p-d pi bonding is **Trisilyl Amine**.

### Summary:
The correct answer is **Trisilyl Amine**.