Question

Identify neutral ligand from following.

• A. Nitrato
• B. Cyano
• C. Aqua
• D. Iodo

Hint:

Common neutral ligands are: \[ \text{H}_2\text{O},\ \text{NH}_3,\ \text{CO},\ \text{NO} \]

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
In coordination chemistry, a ligand is an ion or molecule that binds to a central metal atom to form a coordination complex.
Ligands are classified based on their electrical charge as anionic (negative charge), cationic (positive charge), or neutral (no charge).
Step 2: Key Formula or Approach:
Determine the electrical charge of each given ligand by recalling its chemical formula and standard ionic state in coordination complexes.
A neutral ligand has a net charge of zero.
Step 3: Detailed Explanation:
Let's analyze the chemical nature and charge of each ligand provided in the options:
(A) Nitrato: This corresponds to the nitrate ion. Its chemical formula is \(\text{NO}_3^-\). It carries a negative one charge, so it is an anionic ligand.
(B) Cyano: This corresponds to the cyanide ion. Its chemical formula is \(\text{CN}^-\). It carries a negative one charge, making it an anionic ligand.
(D) Iodo: This corresponds to the iodide ion. Its chemical formula is \(\text{I}^-\). It also carries a negative one charge, thus it is an anionic ligand.
(C) Aqua: This is the IUPAC naming convention for a water molecule when it acts as a ligand. Its chemical formula is \(\text{H}_2\text{O}\).
Water is an intact molecule with no overall electrical charge. It donates an electron pair from the oxygen atom.
Because it carries zero net charge, it is classified as a neutral ligand.
Step 4: Final Answer:
Among the given options, Aqua is the only neutral ligand.