The hybridization states of the central atom in the complexes [Fe(CN)6]^3-, [Fe(CN)6]^4- and [Co(NO2 — Coordination Compounds Chemistry Question

💡 Solution & Explanation

Step 1: Identify that all three complexes are octahedral and coordinated by strong-field ligands (CN^- and NO2^-) which force the pairing of d-electrons. Step 2: Pairing leaves the two inner 3d orbitals (d_x^2-y^2 and d_z^2) completely vacant to participate in hybridization. Step 3: Consequently, all three complexes undergo low-spin inner-orbital d^2sp^3 hybridization, making option (d) the correct answer.