Question

The gas phase cobalt(II) free ion has a ⁴F ground term which in an octahedral ligand field splits into ⁴T_1g (-0.6 Δ_o - CI) , ⁴T_2g(+0 .2 Δ_o) and    ⁴A_2g (+1,2 Δ_o ) electronic states.

   a/What are the Δ_o and CI values for an octahedral Co(II) complex that has ligand field transitions at Δν₁ =7,400cm^-1 (⁴T_2g ←⁴T_1g) and Δν₂ =15,400cm^-1(⁴A_2g ←⁴T_1g) ?

b/ Provide an explanation for the difference in effective magnetic moments between K₂[CoCl₄] (μ_eff(298K) = 3.9 β) and K₄[CoCl₆] (μ_{eff (298K)}= 5.0β) . (β = electron Bohr Magneton)

Answer 1