Mössbauer Studies on Spin State of the Thermal Decomposition of Substituted Tris (2-Pyridylimine) Iron (II) Thiocyanate

The spin states of iron (II) in FeL₂(NCS)₂ produced from the thermal decomposition of FeL₈(NCS)₂ (L=2-py-CR₁=NR₂, R₁ or R₂=H, Me(CH₃), Ph) under nitrogen atmosphere are investigated by means of Mössbauer spectroscopy and magnetic measurements. It was found that the spin states of iron (II) in substitutited bis (2-pyridylimine) iron (II) thiocyanate are included: intermediate-spin (³T₁, S=1), mixed-spin of ⁵T₂(S=2)+³T₁ and spin incomplete transition of ⁵T₂?³T₁.