This is because, three electrons enter \(t_{2 g}\) level and are unpaired. When fourth
electron is present its position (in \(t_{2 g}\) or \(-g\) level) will be determined by the
strength of the ligand field.
$(I)$ સિસ $- [Co(NH_3)_2(en)_2]^{3+}$ $(II)$ ટ્રાન્સ $-[IrCl_2(C_2O_4)_2]^{3-}$
$(III)\, [Rh(en)_3]^{3+}$ $(IV)$ સિસ $-[Ir(H_2O)_3Cl_3$
સંકીર્ણ $-$ અયુગ્મિત ઇલેક્ટ્રોનની સંખ્યા