Coordination compounds

Definition

Coordination compounds are complex molecules consisting of a central metal atom or ion bonded to surrounding molecules or anions, called ligands. These compounds exhibit unique chemical and physical properties due to the interactions between the central metal and its ligands.

5 Must Know Facts For Your Next Test

1. Coordination number refers to the number of ligand donor atoms bonded to the central metal ion.
2. Ligands can be monodentate, bidentate, or polydentate depending on the number of donor atoms they have.
3. The geometry of coordination compounds can be tetrahedral, square planar, or octahedral based on the coordination number and nature of ligands.
4. Crystal Field Theory explains the electronic structure and color properties of coordination compounds by considering the effect of ligand fields on d-orbitals.
5. Chelation is a process where polydentate ligands form multiple bonds with a single metal ion, increasing stability.

Review Questions

Related terms

Ligand:

A molecule or ion that donates at least one pair of electrons to a central metal atom or ion in a coordination compound.

Chelate: A complex formed when a polydentate ligand binds to a central metal ion through multiple bonds.

Crystal Field Theory:

A model that describes the effect of ligand electric fields on the energy levels (d-orbitals) within transition metals.