Which of the following has maximum bond angle around oxygen ?

Options

A. `CH_(3)-O-CH_(3)`
B. `C_(2)H_(5)-O-C_(6)H_(5)`
C.
D. Same in all

Answer

To determine which of the given compounds has the maximum bond angle around the oxygen atom, we will analyze the structures of the compounds and the steric effects of the groups attached to the oxygen.

### Step-by-Step Solution:

1. **Identify the Compounds**:
The compounds we are analyzing are:
- Dimethyl ether (CH3-O-CH3)
- Ethyl phenyl ether (C2H5-O-C6H5)
- Diphenyl ether (C6H5-O-C6H5)

2. **Draw the Structures**:
- **Dimethyl Ether**: The structure is represented as:
```
CH3
|
O
|
CH3
```
- **Ethyl Phenyl Ether**: The structure is:
```
C2H5
|
O
|
C6H5
```
- **Diphenyl Ether**: The structure is:
```
C6H5
|
O
|
C6H5
```

3. **Consider Lone Pairs on Oxygen**:
Each oxygen atom in these ethers has two lone pairs. The presence of lone pairs affects the bond angles due to repulsion.

4. **Analyze Steric Hindrance**:
- In **dimethyl ether**, the two methyl groups (CH3) are relatively small, leading to a smaller bond angle.
- In **ethyl phenyl ether**, the ethyl group (C2H5) is larger than a methyl group, and the phenyl group (C6H5) is bulky but not as much as two phenyl groups.
- In **diphenyl ether**, both groups attached to the oxygen are phenyl groups, which are quite bulky.

5. **Evaluate Bond Angles**:
- The bond angle in dimethyl ether is around 109.5° due to the tetrahedral arrangement of the electron pairs.
- The bond angle in ethyl phenyl ether will be slightly larger than in dimethyl ether due to the presence of the phenyl group, but not significantly.
- The bond angle in diphenyl ether will be the largest because the two bulky phenyl groups will repel each other more than the smaller groups in the other ethers, leading to a larger bond angle.

6. **Conclusion**:
The compound with the maximum bond angle around oxygen is **Diphenyl Ether (C6H5-O-C6H5)** due to the increased steric repulsion between the two bulky phenyl groups.

### Final Answer:
The compound with the maximum bond angle around oxygen is **Diphenyl Ether (C6H5-O-C6H5)**.

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