Which of the following complex is an outer orbital complex ? — Coordination Compounds Chemistry Question

💡 Solution & Explanation

Step 1: Identify that outer orbital complexes are those that form sp^3d^2 hybrid orbitals using the outer d-orbitals. Step 2: Analyze the hybridization of the complexes: [Mn(CN)6]^4- is d^2sp^3, [Co(NH3)6]^3+ is d^2sp^3, and [Fe(CN)6]^4- is d^2sp^3. All three are inner orbital complexes. Step 3: [Ni(NH3)6]^2+ with a d^8 configuration has only sp^3d^2 hybridization available, which makes it an outer orbital complex (option a).