Which of the following molecules involves the formation of `dpi - p pi` bonding ?

Options

A. Trimethyl amine
B. Carbon monoxide
C. Trisilyl amine
D. `C_3O_2`

Answer

To determine which molecule involves the formation of Dπ-Pπ bonding, we need to analyze the given options based on the presence of d orbitals and p orbitals in their constituent atoms. Dπ-Pπ bonding occurs when a d orbital from one atom overlaps with a p orbital from another atom.

### Step-by-Step Solution:

1. **Understanding Dπ-Pπ Bonding**:
- Dπ-Pπ bonding requires one atom to have d orbitals and another atom to have p orbitals.

2. **Analyzing Option A: Trimethylamine (N(CH3)3)**:
- **Nitrogen (N)**: Atomic number = 7; Electron configuration = 1s² 2s² 2p³ (no d orbitals).
- **Carbon (C)**: Atomic number = 6; Electron configuration = 1s² 2s² 2p² (no d orbitals).
- **Conclusion**: Neither nitrogen nor carbon has d orbitals. Therefore, no Dπ-Pπ bonding occurs. **(Not the answer)**

3. **Analyzing Option B: Carbon Monoxide (CO)**:
- **Carbon (C)**: Atomic number = 6; Electron configuration = 1s² 2s² 2p² (no d orbitals).
- **Oxygen (O)**: Atomic number = 8; Electron configuration = 1s² 2s² 2p⁴ (no d orbitals).
- **Conclusion**: Neither carbon nor oxygen has d orbitals. Therefore, no Dπ-Pπ bonding occurs. **(Not the answer)**

4. **Analyzing Option C: C3O2 (Tricarbon Dioxide)**:
- **Carbon (C)**: Each carbon has the same configuration as above (no d orbitals).
- **Oxygen (O)**: Each oxygen has the same configuration as above (no d orbitals).
- **Conclusion**: Neither carbon nor oxygen has d orbitals. Therefore, no Dπ-Pπ bonding occurs. **(Not the answer)**

5. **Analyzing Option D: Trisilyl Amine (N(SiH3)3)**:
- **Nitrogen (N)**: Atomic number = 7; Electron configuration = 1s² 2s² 2p³ (has p orbitals).
- **Silicon (Si)**: Atomic number = 14; Electron configuration = 1s² 2s² 2p⁶ 3s² 3p² (has empty 3d orbitals).
- **Conclusion**: Nitrogen has p orbitals and silicon has d orbitals. Therefore, Dπ-Pπ bonding occurs in this molecule. **(This is the answer)**

### Final Answer:
The molecule that involves the formation of Dπ-Pπ bonding is **Trisilyl Amine (Option D)**.