JEE Main2014ChemistryCoordination CompoundsActual
The octahedral complex of a metal ion M 3 + with four monodentate ligands L 1 , L 2 , L 3 and L 4 absorb wavelengths in the region of red, green, yellow and blue, respectively. The increasing order of ligand strength of the four ligands is
Options
- AL 4   <   L 3   <   L 2   <   L 1
- BL 1   <   L 3   <   L 2   <   L 4
- CL 3   <   L 2   <   L 4   <   L 1
- DL 1   <   L 2   <   L 4   <   L 3
Correct answer
B. L 1   <   L 3   <   L 2   <   L 4
Step-by-step solution
The colors of wavelengths are absorbed in decreasing order of wavelengths. λ red > λ yellow > λ green > λ blue as ΔE = hc λ Δ E Red < Δ E Yellow < Δ E Green < Δ E Blue L 1   <   L 3   <   L 2   <   L 4 As the order of ligand field strength provides the order of relative crystal field splitting energies.