Question

Write the optical isomers of [Cr(C₂O₄)₃]³⁻.

Answer 1

1. The complex [Cr(C₂O₄)₃]³⁻ exhibits optical isomerism because it contains three bidentate oxalate ligands that coordinate to the central Cr³⁺ ion in an octahedral geometry.
2. The chelation by the oxalate ligands creates an asymmetrical, chiral arrangement that leads to the formation of two non-superimposable mirror images, known as optical isomers.
3. These isomers are designated as the Δ-isomer and the Λ-isomer, depending on the spatial arrangement of the ligands around the chromium ion.
4. The Δ-isomer has a right-handed (clockwise) arrangement, while the Λ-isomer has a left-handed (anticlockwise) arrangement. Both isomers rotate plane-polarised light in opposite directions and are mirror images of each other, but they cannot be superimposed.