Synthesis, crystal structures and properties of iron(III) complexes exhibited both high-spin and low-spin states within the crystal lattice

The structures of two novel iron(III) complexes indicate that they have [FeTp2]+ cations where Fe(III) ions are in typical low-spin state, and in counter ions, [TpFe(NCS)3]− for 1 and [Fe(NCS)6]3− for 2 are both in high-spin state. Variable temperature magnetic susceptibility results also show that there are double spin states of iron(III) ions within the crystal lattice.