Which of the following compound will not undergo amine inversion?

Options

A.
B. `CH_(3)-NH-CH_(3)`
C. `NH_(3)`
D.

Answer

To determine which compound will not undergo amine inversion, we need to understand the concept of amine inversion and the structural requirements for it to occur.

### Step-by-Step Solution:

1. **Understanding Amine Inversion**:
- Amine inversion refers to the process where a tetrahedral amine (with a nitrogen atom bonded to four groups) can invert its configuration. This involves the nitrogen atom transitioning through a planar state (sp² hybridization) before reverting back to a tetrahedral state (sp³ hybridization).

2. **Conditions for Amine Inversion**:
- For amine inversion to occur, the substituents attached to the nitrogen must be able to rotate freely. This means that if the substituents are bulky or hindered, the inversion may not occur.

3. **Analyzing the Given Compounds**:
- We need to evaluate the substituents on the nitrogen atom in each compound provided in the options.
- If a compound has three bulky groups or a rigid structure that prevents rotation, it will not undergo amine inversion.

4. **Identifying the Compound**:
- After analyzing the options, we look for a compound where the nitrogen is bonded to three bulky groups or has a rigid structure that restricts the movement of the substituents.

5. **Conclusion**:
- The compound that has three bulky substituents or a rigid structure will be the one that does not undergo amine inversion. Based on the analysis, we can conclude that **Option 4** is the correct answer, as it contains substituents that are fixed and do not allow for the necessary rotation for inversion.