ligand types

Question

Which ligand is ambidentate?

RankGuru · Accepted Answer

1. **Ambidentate Definition**: A ligand that has more than one donor atom but coordinates through only one of them at a time during complex formation.
2. **Evaluation**:
   - **$SCN^-$ (Thiocyanate)**: It can coordinate through Sulfur ($M-SCN$, thiocyanato) or through Nitrogen ($M-NCS$, isothiocyanato).
   - **$CN^-$ (Cyanide)**: Ideally ambidentate (can bind via C or N), but practically binds almost exclusively through Carbon in stable complexes. In standard textbooks, $SCN^-$ and $NO_2^-$ are the classic examples of ambidentate behavior.
   - **$NH_3$**: Monodentate via $N$.
   - **en**: Bidentate via both $N$ atoms simultaneously.
3. **Answer**: **$SCN^-$** is the most characteristic ambidentate ligand listed.

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ligand types

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