Lanthanides predominantly exist in the +3 oxidation state.
Understanding Lanthanide Oxidation States
The most stable and commonly observed oxidation state for lanthanide elements is +3. This arises from the electronic configuration changes the lanthanides undergo to achieve stability.
Why +3 is the most stable state
- Electron Removal: Lanthanides readily lose the two 6s electrons and one 4f electron to attain the +3 oxidation state.
- Electronic Configuration: Achieving the +3 state often results in a more stable electronic configuration, particularly for elements like Lanthanum (La), Gadolinium (Gd), and Lutetium (Lu), which attain empty, half-filled, or fully filled 4f subshells, respectively.
- Energy Considerations: According to the provided reference, removing further electrons from the 4f subshell requires significantly more energy due to the large energy difference between the 4f and 6s orbitals. This makes higher oxidation states less favorable.
Other Possible Oxidation States
While +3 is dominant, some lanthanides can also exhibit +2 and +4 oxidation states, though less frequently. These exceptions arise when forming these other oxidation states leads to a particularly stable electronic configuration.
