Consider the following coordination complexes: [Fe(CN) ₆ ] ³⁻ , [Co(NH ₃ ) ₆ ] ³⁺ , [Mn(CN) ₆ ] ³⁻ , [Cr(H ₂ O) ₆ ] ³⁺ , [Fe(H ₂ O) ₆ ] ³⁺ , [Ni(NH ₃ ) ₆ ] ²⁺ The number of complexes that are BOTH inner orbital complexes AND paramagnetic in nature is

Step-by-step solution

For a complex to be an inner orbital complex, it must use inner (n-1)d orbitals for hybridization (i.e., d^2sp^3 ). For it to be paramagnetic, it must have at least one unpaired electron. 1. [Fe(CN) ₆ ] ³⁻ : Fe ³⁺ is 3d^5 . CN ^- is a strong field ligand. Configuration is t_ 2g ^5 e_g^0 . It is an inner orbital complex ( d^2sp^3 ) and has 1 unpaired electron (paramagnetic). 2. [Co(NH ₃ ) ₆ ] ³⁺ : Co ³⁺ is 3d^6 . NH ₃ acts as a strong field ligand for Co ³⁺ . Configuration is t_ 2g ^6 e_g^0 . It is an inner orbital