Low-spin complexes

Definition

Low-spin complexes are coordination compounds where electrons prefer to pair up in lower energy orbitals before occupying higher energy ones, resulting from strong field ligands. These complexes often exhibit lower magnetic moments due to fewer unpaired electrons.

5 Must Know Facts For Your Next Test

1. Low-spin complexes typically form with strong field ligands such as CN- and CO.
2. They have a smaller number of unpaired electrons compared to high-spin complexes, leading to lower magnetic moments.
3. These complexes are more likely to be seen in octahedral geometries than in tetrahedral ones due to crystal field splitting differences.
4. Low-spin configurations are more common for metal ions with d4, d5, d6, or d7 electron counts in the presence of strong field ligands.
5. Spectroscopic properties of low-spin complexes often show larger energy gaps between split d-orbitals compared to high-spin counterparts.

Review Questions

• What type of ligands typically lead to the formation of low-spin complexes?
• How do the magnetic properties of low-spin complexes compare to those of high-spin complexes?
• In which geometric arrangement are low-spin complexes more commonly found?

Related terms

High-Spin Complexes: Coordination compounds where electrons occupy higher energy orbitals before pairing up, typically forming with weak field ligands and exhibiting higher magnetic moments.

Crystal Field Splitting: The process by which degenerate d-orbitals split into different energy levels upon interaction with a ligand's electric field.

Ligand Field Theory:

A theory that describes the bonding, orbital arrangement, and other characteristics of coordination compounds using molecular orbital theory.