A ncw series of polynuclcar iron complexes with polydiimine ligand have becn preparcd from thc Schiff-base condensation of pyridine-2,G-diafdehydc or 2,6-diacetylpyridinc with aliphatic diamines. Thc structurcs of the complcxcs arc represcntcd by [-N= CR-Py-CR = N-(CHZ)~-]~FCSO~.XH~O; wherc R = H, CH3; n =1-10, 7. = 5-8. Mijssbauer spectra and magnetic measurements show sevcral complexes have unusual magnetic propertics.