Identify the correct statements for the behavior of ethane-1,2-diamine as a ligand.
(A) it is a neutral ligand
(B) it is a bidentate ligand
(C) it is an ambidentate ligand
(D) it is a chelating ligand
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → (A), (B) and (D) only
Option A: It is a neutral ligand
Ethane-1,2-diamine (en) has no overall charge in its free molecular form. Both nitrogen atoms donate lone pairs without the ligand itself being charged. Therefore, it behaves as a neutral ligand.
Option B: It is a bidentate ligand
The molecule contains two nitrogen donor atoms, each with a lone pair. Both can coordinate simultaneously to the same metal ion. Hence, ethane-1,2-diamine is a bidentate ligand.
Option C: It is an ambidentate ligand
Ambidentate ligands have two different donor atoms but bind through only one at a time (like NO₂⁻ via N or O). Ethane-1,2-diamine uses both nitrogen atoms together, not alternatively. So, it is not ambidentate.
Option D: It is a chelating ligand
When both nitrogen atoms attach to the same metal ion, a five-membered ring is formed. Ligands that form rings with the metal are called chelating ligands. Thus, en is chelating.
Hence, A ,B and D are correct.