9701 · 28.4
Stereoisomerism in transition element complexes
Just like organic molecules, the 3D arrangement of ligands around a central metal ion can create different isomers. These stereoisomers have the same chemical formula and bonds but differ in their spatial layout, leading to unique properties.
Need to know
What you need to know
- **Cis**: Identical ligands are adjacent to each other (90° apart in square planar and octahedral).
- **Trans**: Identical ligands are opposite each other (180° apart).
Explanation
Complex Shapes: A 3D Puzzle
- Octahedral MX₆: cis/trans isomerism with two identical ligands. | Sim hint: Cis: adjacent; trans: opposite positions.
- Square planar and octahedral optical isomerism possible. | Sim hint: No plane of symmetry in complex.
- Bidentate ligands (en) enable optical isomers in [M(en)₃]ⁿ⁺. | Sim hint: Δ and Λ enantiomers.
- Contrast with organic stereoisomerism — chiral at metal centre rare. | Sim hint: Focus on ligand arrangement.