Assign the hybridization, shape and magnetic moment of [Cu(CN)4]: — Coordination Compounds Chemistry Question

💡 Solution & Explanation

# Analysis of $K_3[Cu(CN)_4]$ **Step 1: Identify the central metal and ligand** - Central metal: Cu⁺ (from $K_3$ donating 3 electrons, Cu is +1) - Ligand: $CN^-$ (cyanide, a strong field ligand) **Step 2: Determine electron configuration of Cu⁺** - Cu: [Ar]3d¹⁰4s¹ - Cu⁺: [Ar]3d¹⁰ (loses the 4s electron) - d-electrons: **10** (completely filled d-subshell) **Step 3: Assess the crystal field splitting** - $CN^-$ is a **strong field ligand** → causes high spin-pairing - With 10 d-electrons in a tetrahedral/square planar geometry, all electrons are paired - Configuration results in **diamagnetic** complex **Step 4: Determine geometry and hybridization** - Cu⁺ with 4 ligands can adopt **square planar** or **tetrahedral** geometry - $CN^-$ strongly prefers linear coordination → complex is likely **square planar** - Hybridization for square planar: **$dsp^2$** (or $d_{x^2-y^2}sp^2$) **Step 5: Calculate magnetic moment** - All 10 d-electrons are paired - Number of unpaired electrons: **0** - Magnetic moment: $\mu = \sqrt{n(n+2)}BM = \sqrt{0} = \mathbf{0\, BM}$ (diamagnetic) **Answer (Option B):** - **Hybridization:** $dsp^2$ - **Shape:** Square planar - **Magnetic moment:** 0 BM (diamagnetic)