Which of the following is an inner orbital, low-spin octahedral complex? — Coordination Compounds Chemistry Question

💡 Solution & Explanation

$Co^{3+}$ with $NH_3$ (strong field ligand) forces electron pairing in the 3d orbitals, resulting in an inner orbital $d^2sp^3$ complex with zero unpaired electrons (low spin). The others contain weak field ligands forming $sp^3d^2$ high-spin complexes.