Chemistry · Coordination Compounds · NEET
Look only at the KIND of ligand, not the number. Homoleptic = the metal is bound to only one kind of donor group (all ligands are the same). Heteroleptic = the metal is bound to more than one kind of donor group (two or more different ligands). This is the exact NCERT wording, so learn it in these words for NEET.
No. This is the most common mistake. [Co(NH3)6]3+ has 6 ligands but all are NH3, so it is homoleptic. [Ni(CO)4] has 4 ligands but all are CO, so it is still homoleptic. What matters is how many DIFFERENT types of ligand there are, not how many ligand groups in total.
It is homoleptic. The cobalt is bound only to NH3 (ammine) ligands. There is just one kind of ligand, so it is homoleptic. This is the exact example NCERT uses, and it appeared in NEET 2024.
Only count what is INSIDE the coordination sphere (inside the square brackets and directly bound to the metal). Water written outside the brackets, like in [Ni(H2O)6]Cl2.something, that sits outside is not a ligand. Inside [Cr(NH3)3(H2O)3]Cl3, both NH3 and H2O are ligands and are different kinds, so it is heteroleptic.
Read the coordination sphere and list the ligand names. If you see only ONE ligand word (like only 'oxalato' or only 'ammine'), it is homoleptic. If you see two or more different ligand words (ammine AND chlorido, or aqua AND ammine), it is heteroleptic. In NEET 2023 only K3[Al(C2O4)3] had a single ligand type.
Homoleptic complexes with identical ligands usually have higher symmetry, but 'homoleptic' only tells you the ligands are all the same type. It does not by itself tell you the shape or whether isomers exist. For NEET, just use it to classify one-ligand-type vs many-ligand-type complexes.
The homoleptic complex from the following complexes is:
Statement I: [Co(NH3)6]3+ is a homoleptic complex whereas [Co(NH3)4Cl2]+ is a heteroleptic complex. Statement II: Complex [Co(NH3)6]3+ has one kind of ligands but [Co(NH3)4Cl2]+ has more than one kind of ligands. Choose the correct answer:
Try the real previous-year questions from this chapter — each with the answer and a full solution.
Homoleptic: the metal is bound to only one kind of ligand (e.g. [Ni(CO)4]). Heteroleptic: the metal is bound to more than one kind of ligand (e.g. [Co(NH3)4Cl2]+).
NCERT uses [Co(NH3)6]3+ as homoleptic (only NH3) and [Co(NH3)4Cl2]+ as heteroleptic (NH3 and Cl). Memorise these two exactly.
Yes. [Al(C2O4)3]3- has three oxalate (bidentate) ligands, all the same kind, so it is homoleptic. The ligand type being the same is what matters, not whether it is monodentate or bidentate.
NEET has directly asked to identify the homoleptic complex from a list (2023) and as a true/false statement pair (2024). It is a quick, guaranteed mark if you know the one-line definition and can read a coordination sphere.
Homoleptic/heteroleptic is about how many KINDS of ligand are present. A chelate is about one ligand using two or more donor atoms to grip the metal in a ring. A complex can be homoleptic and also contain chelate ligands, like [Al(C2O4)3]3-.
