Mono- and binuclear iron(III) complexes with the general formula [FeXL] and [LFe-Y-FeL](BPh4)2 have been prepared and their spin states of the iron atom in the complexes has been investigated by means of the temperature-dependent Mössbauer spectroscopy and magnetic measurements, where X is a methyl-substituted pyridine, L denotes a quinquedentate Schiff-base derived from salicylaldehyde with N-(2-aminoethyl)-1,3-propanediamine and Y denotes bridged ligands such as pyrazine(pyr), 4,4′-pyridine(bpy), 4,4′-vinylenepyridine(vipy). On the basis of the Mössbauer and magnetic data, it was concluded that the spintransition characteristics depends on the methyl substituent of pyridine and the bridged ligand.
