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:

(A), (B) and (D) only

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.