Which of the following series contains nucleophiles only ?

Options

A. `BF_3 , AlCl_3 , NH_3`
B. `RCH_2^(-) , bar(C)N , CH_3CH_2OH`
C. `BF_3,bar(N)H_2,H_2O`
D. `RNH_2,:"CCl"_2H^(-)`

Answer

To determine which series contains only nucleophiles, we need to analyze each option provided in the question. A nucleophile is a species that donates an electron pair to form a chemical bond, typically characterized by having a lone pair of electrons or a negative charge.

### Step-by-Step Solution:

1. **Identify the Options**:
We are given four options. We will analyze each option to identify whether it contains only nucleophiles.

2. **Analyze Option 1**:
- Contains PF3 and BF3.
- PF3: Phosphorus has a complete octet but is electron deficient; thus, it behaves as an electrophile.
- BF3: Boron is electron deficient (only has 6 electrons), making it an electrophile.
- **Conclusion**: Option 1 contains electrophiles.

3. **Analyze Option 2**:
- Contains R-CH2^- (negatively charged), CN^-, and CH3-CH2-OH.
- R-CH2^-: The negative charge indicates it is a nucleophile.
- CN^-: The carbon in cyanide has a negative charge, making it a nucleophile.
- CH3-CH2-OH: The oxygen has lone pairs and can donate electrons, acting as a nucleophile.
- **Conclusion**: Option 2 contains only nucleophiles.

4. **Analyze Option 3**:
- Contains BF3 and another compound.
- BF3: As established, it is an electrophile.
- **Conclusion**: Option 3 contains electrophiles.

5. **Analyze Option 4**:
- Contains R-NH2 and another compound.
- R-NH2: The nitrogen has a lone pair, making it a nucleophile.
- However, if there are any other compounds in this option that are electrophiles, it would disqualify this option.
- **Conclusion**: Without further analysis, this option may contain nucleophiles but needs verification against other compounds.

6. **Final Conclusion**:
- After analyzing all options, **Option 2** is the only one that contains only nucleophiles.

### Answer:
**The series that contains only nucleophiles is Option 2.**