Diethylene triamine is:

Options

A. Chelating ligand
B. Polydentate ligand
C. Tridentate ligand
D. All of these

Explanation

To determine the characteristics of diethylene triamine, we can follow these steps:

### Step 1: Identify the Structure
Diethylene triamine (often abbreviated as DETA) has the following structure:
- It consists of three amine groups (-NH2) connected by two ethylene (-CH2-CH2-) units.
- The full structure can be represented as: NH2-CH2-CH2-NH-CH2-CH2-NH2.

### Step 2: Determine the Denticity
- Denticity refers to the number of donor atoms in a ligand that can coordinate to a central metal atom.
- In diethylene triamine, there are three nitrogen atoms that can donate lone pairs of electrons to a metal ion.

### Step 3: Classify the Ligand
- Since diethylene triamine has three donor sites (the three nitrogen atoms), it is classified as a tri-dentate ligand.
- Additionally, because it has more than one donor site, it is also classified as a poly-dentate ligand.

### Step 4: Identify Chelating Properties
- A chelating ligand is one that can form multiple bonds to a single metal ion, creating a ring structure.
- Diethylene triamine, due to its tri-dentate nature, can form chelate complexes with metal ions.

### Step 5: Conclusion
- Based on the above analysis, diethylene triamine is a tri-dentate ligand, a chelating ligand, and a poly-dentate ligand.

### Final Answer
Diethylene triamine is a tri-dentate ligand, a chelating ligand, and a poly-dentate ligand.

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