Condensation polymers of dicyclopentadienyl iron with aromatic diazoium salts and magnetism

Abstract Five kinds of condensation polymers of dicyclopentadienyl iron with aromatic diazoium salts were firstly composed. Using inductively coupled plasma (ICP) and FT‐IR their structures were characterized. Their thermal stability was discussed using TG and DTA. The electronic structure of iron was studied by Mössbauer spectra and electron spin resonance (ESR) spectra. Measurement of temperature dependence of the magnetic property ( M – T curve) of the condensation polymers indicates that they have stronger magnetism. At a temperature of T = 1.5 K, the loop of magnetic hysteresis was obtained. The strongest magnetic condensation polymer was benzyl ferrocene making 1/ χ m − T , obtaining a condensation temperature of T c = 20.5 K, when T < T c , the condensation polymer shows ferromagnetism. Copyright © 2004 John Wiley & Sons, Ltd.