Oxidative Addition
- The metal breaks a bond in a molecule (like H–H or C–X).
- Both pieces of that bond attach to the metal.
- The metal ends up with more ligands and a higher oxidation state.
Example: A metal splits H₂ into two M–H bonds.
Reductive Elimination (opposite step)
- Two groups on the metal join together and leave as a molecule (like H₂, CH₄, or R–R).
- The metal has fewer ligands and a lower oxidation state.
Example: Two M–H bonds combine and release H₂.
In short:
- Oxidative addition = metal grabs and splits a bond.
- Reductive elimination = metal lets two groups go as a bond.