Which of the following is not an ambidentate ligand?

Options

A. CN
B. `NO_(2)`
C. `SCN^(-)`
D. `NH_(3)`

Answer

To determine which of the following is not an ambidentate ligand, we first need to understand what an ambidentate ligand is.

### Step-by-Step Solution:

1. **Definition of Ambidentate Ligands**:
- Ambidentate ligands are ligands that have two donor atoms but can coordinate to the metal center through only one of those donor atoms at a time.

2. **Examples of Ambidentate Ligands**:
- **Cyanide (CN⁻)**: Can coordinate through carbon (C) or nitrogen (N).
- **Nitrite (NO₂⁻)**: Can coordinate through nitrogen (N) or oxygen (O).
- **Thiocyanate (SCN⁻)**: Can coordinate through sulfur (S) or nitrogen (N).

3. **Identifying Non-Ambidentate Ligands**:
- To find the ligand that is not ambidentate, we need to look for a ligand that does not have two donor atoms or does not coordinate through two different atoms.

4. **Analyzing the Given Options**:
- If we consider ligands like water (H₂O), ammonia (NH₃), or chloride (Cl⁻), these are monodentate ligands, as they have only one donor atom that can coordinate to the metal center.

5. **Conclusion**:
- The ligand that does not fit the definition of an ambidentate ligand is the one that does not have two donor atoms or does not coordinate through two different atoms. Based on the examples discussed, the answer to the question is **N (as in nitrogen)**, which is not an ambidentate ligand.

### Final Answer:
The ligand that is not an ambidentate ligand is **N**.

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