An example of ambidentate ligand is

Options

A. `H_2 O`
B. `NO_2^-`
C. `NH_2CH_2CH_2NH_2`
D. `NH_3`

Answer

To determine an example of an ambidentate ligand, we need to understand what ambidentate ligands are and identify a suitable example.

### Step-by-Step Solution:

1. **Definition of Ambidentate Ligands**:
Ambidentate ligands are ligands that have two different atoms that can donate electrons to a central metal atom or ion. These ligands can bind to the metal through either of the two donor atoms.

**Hint**: Remember that ambidentate ligands must have at least two different donor atoms.

2. **Examples of Ligands**:
- Water (H2O) is a common ligand, but it only has one donor atom (oxygen), so it cannot be ambidentate.
- The nitrito ligand (NO2-) is a good example of an ambidentate ligand because it can donate electrons from either the nitrogen atom or the oxygen atom.

**Hint**: Look for ligands that can coordinate through different atoms.

3. **Understanding Nitrito (NO2-)**:
- In the nitrito ion (NO2-), the oxygen atom can donate a pair of electrons to the metal, or the nitrogen atom can also donate a pair of electrons. This dual capability makes it ambidentate.
- When it donates through oxygen, it is called "nitrito-O", and when it donates through nitrogen, it is called "nitrito-N".

**Hint**: Consider how the structure of the ligand allows for different atoms to participate in bonding.

4. **Conclusion**:
Based on the above analysis, the nitrito ion (NO2-) is an example of an ambidentate ligand because it has two different donor atoms (N and O) that can coordinate with a metal center.

**Final Answer**: An example of an ambidentate ligand is **NO2- (nitrito)**.