Which of the following amines from maximum hydrogen bonds within themselves?

Options

A. `CH_3-NH_2`
B. `(CH_3)_2NH`
C. `(CH_3)_3N`
D. None of these

Answer

To determine which amine forms the maximum hydrogen bonds within themselves, we need to analyze the structures of the given amines.

### Step-by-Step Solution:

1. **Identify the Types of Amines**:
- Amines can be classified into primary (1°), secondary (2°), and tertiary (3°) amines based on the number of carbon groups attached to the nitrogen atom.
- Primary amines have one alkyl group attached to the nitrogen, secondary amines have two, and tertiary amines have three.

2. **Understanding Hydrogen Bonding**:
- Hydrogen bonding occurs when a hydrogen atom is bonded to a highly electronegative atom (like nitrogen, oxygen, or fluorine) and interacts with another electronegative atom.
- The ability to form hydrogen bonds depends on the number of hydrogen atoms attached to the nitrogen atom.

3. **Analyze the Given Amines**:
- **Primary Amine (1°)**: For example, CH3NH2 (methylamine) has two hydrogen atoms attached to nitrogen. It can form hydrogen bonds with two other molecules.
- **Secondary Amine (2°)**: For example, CH3NHCH3 (dimethylamine) has one hydrogen atom attached to nitrogen. It can form hydrogen bonds with only one other molecule.
- **Tertiary Amine (3°)**: For example, (CH3)3N (trimethylamine) has no hydrogen atoms attached to nitrogen. It cannot form hydrogen bonds with other amine molecules.

4. **Comparing Hydrogen Bonding Capabilities**:
- The primary amine can form the most hydrogen bonds because it has two hydrogen atoms available for bonding.
- The secondary amine can form fewer hydrogen bonds due to having only one hydrogen atom.
- The tertiary amine cannot form any hydrogen bonds with itself since there are no hydrogen atoms on the nitrogen.

5. **Conclusion**:
- Among the three types of amines, the primary amine forms the maximum number of hydrogen bonds within itself due to having two hydrogen atoms available for bonding.

### Final Answer:
The primary amine (1° amine) forms the maximum hydrogen bonds within themselves.

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