In which of the following octahedral complexes of Co (Z = 27) will the magnitude of Δ0 be the highest?
The spectrochemical series is given below:
I− < Br− < S2− < SCN− < Cl− < NO3− < N3− < F− < OH− < C2O42− < H2O < NCS− < CH3CN < py < NH3
< en < bipy < phen < NO2− < PPh3 < CN− < CO
CN− is the strongest of all the ligands given in the options, and hence, Δ0 is highest for [Co(CN)6]3−.