The ligand `N(CH_2CH_2NH_2)_3` is

Options

A. Tridentate
B. Pentadentate
C. Tetradentate
D. Bidentate

Explanation

To determine the classification of the ligand `N(CH_2CH_2NH_2)_3`, we will analyze its structure and the number of donor atoms it possesses.

### Step-by-Step Solution:

1. **Identify the Structure of the Ligand**:
The ligand `N(CH_2CH_2NH_2)_3` consists of a central nitrogen atom (N) bonded to three ethylene diamine groups (CH2CH2NH2). Each ethylene diamine group has an amino (-NH2) functional group.

2. **Determine the Donor Atoms**:
Each ethylene diamine group can donate one lone pair of electrons from its nitrogen atom to a metal ion. Since there are three ethylene diamine groups, we have:
- 3 nitrogen atoms from the three ethylene diamine groups.

3. **Count the Total Number of Donor Atoms**:
The central nitrogen atom can also be considered as a donor atom. Therefore, we have:
- 3 nitrogen atoms from the ethylene diamine groups + 1 central nitrogen atom = 4 nitrogen donor atoms in total.

4. **Classify the Ligand**:
Since the ligand has 4 donor atoms, it is classified as a tetradentate ligand. Tetradentate ligands can form four coordinate bonds with a metal ion.

### Final Answer:
The ligand `N(CH_2CH_2NH_2)_3` is a **tetradentate ligand**.

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