Which of the following group (s) is/are m-directing ?

Options

A. `-Cl`
B. `-Ph`
C. `-CHO`
D. `-COOH`

Explanation

To determine which of the given groups are meta-directing, we need to analyze the nature of each group in relation to their electron-donating or electron-withdrawing effects. Here’s a step-by-step solution:

### Step 1: Identify the Groups
The groups given in the question are:
1. Cl (Chlorine)
2. Phenyl (C6H5)
3. CHO (Aldehyde)
4. COOH (Carboxylic acid)

### Step 2: Classify the Groups
We need to determine whether each group is electron-donating or electron-withdrawing:
- **Cl (Chlorine)**: This group is a halogen and exhibits a +M (mesomeric) effect due to its ability to donate electrons through resonance. It also has a -I (inductive) effect, but the +M effect is stronger, making it ortho/para-directing.

- **Phenyl (C6H5)**: This group is also an electron-donating group due to resonance (+M effect). It activates the ortho and para positions, making it ortho/para-directing.

- **CHO (Aldehyde)**: This group is an electron-withdrawing group due to its -M effect (it withdraws electrons through resonance) and is therefore meta-directing.

- **COOH (Carboxylic acid)**: Similar to the aldehyde group, the carboxylic acid group is also an electron-withdrawing group (-M effect) and is meta-directing.

### Step 3: Conclusion
Based on the analysis:
- The groups that are meta-directing are **CHO** and **COOH**.
- The groups that are ortho/para-directing are **Cl** and **Phenyl**.

### Final Answer
The groups that are meta-directing are **CHO and COOH**.

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