Which one of the following complex has the highest magnitude of Crystal Field Splitting Energy `(Delta_0)` ?

Options

A. `[Co(H_2O)_6]^(3+)`
B. `[Co(NH_3)_6]^(3+)`
C. `[Co(C_2O_4)_3]^(3-)`
D. `[CoF_6]^(3-)`

Answer

B

Explanation

Crystal field splitting energy (`Delta_0`) depends on ligand field and charge on metal ion.
The spectro chemical series of ligands is,
`I^(-) lt Br^(-) lt SCN^(-) lt Cl^(-) lt F^(-) lt OH^(-) lt C_2O_4^(2-) lt H_2O lt NCS lt EDTA^(4-) lt NH_3 lt en lt CN^(-) lt CO`
From the given options , `NH_3` ligand has highest magnetic field .
`therefore [CO(NH_3)_6]^(3+)` has highest magnitude of crystal field splitting energy .