Homoleptic octahedral complexes of a metal ion '`M^(3+)`' with three monodentate ligands `L_(1),L_(2)` and `L_(3)` absorb wavelengths in the region of green, blue and red respectively. The increasing order of the ligand strength is :

Options

A. `L_(4) lt L_(3) lt L_(2) lt L_(1)`
B. `L_(1) lt L_(2) lt L_(2) lt L_(4)`
C. `L_(3) lt L_(2) lt L_(4) lt L_(1)`
D. `L_(1) lt L_(2) lt L_(4) lt L_(3)`

Answer

B

Explanation

According to crystal field theory .
strength of ligand field `prop 1/(Delta_("absorbed"))`
Decreasing order of
Red(`L_1)` gt Yellow(`L_3`) gt Green (`L_2)` gt Blue (`L_4)` lt Increasing order of ligand field strength .
`L_1 lt L_3 lt L_2 lt L-4`