Which of the following is an unsymmetrical bidentate ligand?

Options

A. gly
B. en
C. ox
D. `SO_(4)^(2-)`

Answer

To determine which of the following is an unsymmetrical bidentate ligand, we need to understand the definitions and characteristics of bidentate ligands and what makes them unsymmetrical.

### Step-by-Step Solution:

1. **Definition of Bidentate Ligands**:
- Bidentate ligands are molecules that can attach to a central metal atom at two different sites. This means they have two donor atoms that can form coordinate bonds with the metal.

2. **Understanding Unsymmetrical Bidentate Ligands**:
- An unsymmetrical bidentate ligand has two different donor atoms. This means that the two atoms that coordinate to the metal are not the same.

3. **Analyzing the Given Ligands**:
- **Glycine (Gly)**: Glycine can be represented as NH2CH2COO-. In this molecule, the donor atoms are nitrogen (N) from the amine group and oxygen (O) from the carboxylate group. Since these donor atoms are different, glycine is an unsymmetrical bidentate ligand.
- **Ethylenediamine (en)**: Ethylenediamine has the structure NH2CH2CH2NH2. Here, both donor atoms are nitrogen (N), making it a symmetrical bidentate ligand.
- **Oxalate (C2O4^2-)**: The oxalate ion has two oxygen (O) donor atoms. Since both donor atoms are the same, it is also a symmetrical bidentate ligand.
- **Sulfate (SO4^2-)**: The sulfate ion has oxygen (O) as its donor atoms. Again, since all donor atoms are the same, it is not an unsymmetrical bidentate ligand.

4. **Conclusion**:
- The only ligand among the options that qualifies as an unsymmetrical bidentate ligand is glycine (Gly).

### Final Answer:
- **Glycine (Gly)** is the unsymmetrical bidentate ligand.