Which of the following behave both as nucleophile as well as an electrophile ?

Options

A. `CH_3 CI`
B. `HC HO`
C. `CH_3 CN`
D. `CH_3 OH`

Answer

To determine which of the given compounds behave both as nucleophiles and electrophiles, we need to understand the definitions and characteristics of each:

1. **Nucleophile**: An electron-rich species that donates an electron pair to form a bond.
2. **Electrophile**: An electron-deficient species that accepts an electron pair to form a bond.

Now, let's analyze the provided compounds step by step:

### Step 1: Analyze CH3Cl (Methyl Chloride)
- **Structure**: CH3Cl has a carbon atom bonded to three hydrogen atoms and one chlorine atom.
- **Nucleophilic Behavior**: The chlorine atom has three lone pairs of electrons, making it a potential nucleophile. However, the carbon atom is not electron-deficient, as it is bonded to hydrogen atoms and chlorine, which is more electronegative.
- **Electrophilic Behavior**: The carbon atom can be considered slightly electrophilic due to the presence of chlorine, which pulls electron density away from carbon. However, it is not a strong electrophile.
- **Conclusion**: CH3Cl can act as a weak nucleophile but is not a strong electrophile.

### Step 2: Analyze HCO (Formaldehyde)
- **Structure**: HCO has a carbon atom double bonded to an oxygen atom and single bonded to a hydrogen atom.
- **Nucleophilic Behavior**: The oxygen atom has lone pairs of electrons, allowing it to act as a nucleophile.
- **Electrophilic Behavior**: The carbon atom is electron-deficient due to the electronegativity of oxygen, making it a good electrophile.
- **Conclusion**: HCO can act as both a nucleophile (due to oxygen) and an electrophile (due to carbon).

### Step 3: Analyze CH3OH (Methanol)
- **Structure**: CH3OH has a carbon atom bonded to three hydrogen atoms and one hydroxyl (OH) group.
- **Nucleophilic Behavior**: The oxygen in the hydroxyl group has lone pairs, allowing it to act as a nucleophile.
- **Electrophilic Behavior**: The carbon atom is not electron-deficient and does not exhibit electrophilic characteristics.
- **Conclusion**: CH3OH can act as a nucleophile but not as an electrophile.

### Step 4: Analyze CH3CN (Acetonitrile)
- **Structure**: CH3CN has a carbon atom bonded to three hydrogen atoms and one nitrogen atom.
- **Nucleophilic Behavior**: The nitrogen atom has a lone pair, making it a nucleophile.
- **Electrophilic Behavior**: The carbon atom is bonded to nitrogen, which is more electronegative, creating a partial positive charge on the carbon. Thus, it can act as an electrophile.
- **Conclusion**: CH3CN can act as both a nucleophile (due to nitrogen) and an electrophile (due to carbon).

### Final Conclusion
The compounds that behave as both nucleophiles and electrophiles are:
- HCO (Formaldehyde)
- CH3CN (Acetonitrile)

### Summary of Results
- **CH3Cl**: Weak nucleophile, not a strong electrophile.
- **HCO**: Both nucleophile and electrophile.
- **CH3OH**: Nucleophile only.
- **CH3CN**: Both nucleophile and electrophile.