Question

Which one of the following following is an example of a chelate?

• A. Cisplatin
• B. Hemoglobin
• C. Iodine
• D. Ferrocene

Answer 1

The Correct Option is B

To determine which among the given options is an example of a chelate, let's first understand what a chelate is.

Chelation is a type of bonding of ions and molecules to metal ions. It is a process where a metal ion is bound to an organic molecule to form a ring-like complex. Such complexes are illustrated by the presence of a central metal atom bonded to a large organic molecule, which encases it through multiple coordination bonds.

Now, let's evaluate each option:

1. Cisplatin: Cisplatin is an inorganic chemical compound used as a chemotherapy drug. It does not feature the multi-dentate ligand structure necessary to form a chelate.
2. Hemoglobin: Hemoglobin is a protein molecule that contains iron and is essential for transporting oxygen in the blood. In the hemoglobin molecule, the iron is centrally coordinated by porphyrin as a ligand, forming a stable ring structure typical of chelates. Therefore, hemoglobin is a classic example of a chelate.
3. Iodine: Iodine is a simple diatomic molecule, not known for forming chelates.
4. Ferrocene: Ferrocene is an organometallic compound, composed of two cyclopentadienyl rings bound to a central iron atom. Although it resembles chelation due to cyclic structures, its bonding type is different and does not typically qualify as a chelate in the traditional sense of biological chelates.

The correct answer is Hemoglobin, as it is the only option in the list that fits the description of a chelate, with a metal ion (iron) coordinated by a chelating agent (the porphyrin ring) to form a stable complex.