Coordination Compounds — Important Questions

NH₃, Cl⁻, H₂O

Monodentate ligands have only one donor atom. NH₃ (N donor), Cl⁻ (Cl donor), and H₂O (O donor) are monodentate. En and oxalate are bidentate ligands.

Bidentate ligand

Ethylenediamine (H₂N-CH₂-CH₂-NH₂) has two nitrogen atoms as donor atoms, making it a bidentate ligand.

t₂g (3 orbitals) and eg (2 orbitals)

In octahedral complexes, the five d orbitals split into t₂g set (dxy, dyz, dxz - lower energy) and eg set (dx²-y², dz² - higher energy).

Ligands are electron pair donors, Central metal ion is a Lewis acid, Counter ions are outside the coordination sphere

Ligands donate electron pairs (Lewis bases) to metal ions (Lewis acids). Counter ions balance charge outside coordination sphere. Coordination bonds are covalent, not ionic.