Spectrochemical series
Coordination Compounds · Chemistry
Study notes
[CoF₆]³⁻ is high-spin but [Co(CN)₆]³⁻ is low-spin. Explain. Step 1: Co³⁺ is d⁶. Spin state depends on Δ₀ vs pairing energy P. Step 2: F⁻ is weak-field (early in series) → Δ₀ < P → electrons stay unpaired (t₂g⁴e_g²). Step 3: CN⁻ is strong-field (late) → Δ₀ > P → electrons pair up (t₂g⁶). Step 4: Same metal, different ligand → different magnetism! The series predicts it.