High-spin complexes
- Happen with weak ligands (like water, chloride).
- The energy gap between orbitals is small.
- Electrons prefer to stay unpaired and spread out.
- This makes the complex have more unpaired electrons → stronger magnetism.
Low-spin complexes
- Happen with strong ligands (like cyanide, carbon monoxide).
- The energy gap between orbitals is large.
- Electrons prefer to pair up in lower orbitals rather than spread out.
- This makes the complex have fewer unpaired electrons → weaker or no magnetism.
In short:
- High-spin = weak ligands, more unpaired electrons, stronger magnetism
- Low-spin = strong ligands, fewer unpaired electrons, weaker magnetism