Chemistry - Coordination Chemistry Question with Solution | TestHub

Given complex: $[C{r}^{III}(L-L{)}_3{]}^{3+}$

This is an octahedral complex of type $M(L-L{)}_3$, which shows optical isomerism (Δ and Λ forms) when the bidentate ligand is symmetrical and does not create additional geometrical constraints.

Check ligands:

(a) Oxalate (C₂O₄²⁻) → symmetric bidentate, but gives only one type of chelate arrangement in this context

(b) en (ethylenediamine)→ classic symmetric bidentate → gives Δ/Λ optical isomers

(c) bipy (2,2'-bipyridine) → symmetric rigid bidentate → also gives Δ/Λ forms

(d) Gly⁻ (glycinato) → unsymmetrical (O and N donor) → can lead to complications, not pure Δ/Λ pair

So correct ligands are: (B) and (C)