Ferrocene-containing polyphenylenes as precursors of magnetic nanomaterials

New magnetic nanomaterials based on ferrocene-containing polyphenylenes were obtained. The reaction of polycyclocondensation of 1,1′-diacetylferrocene in the presence of triethyl orthoformate and p -toluenesulfonic acid within 20–200°C under common conditions and in supercritical carbon dioxide (scCO 2 ) was carried out for the first time to give highly branched ferrocene-containing polyphenylenes as precursors of magnetic nanomaterials. The heating of the polyphenylenes in the range of 200–750°C resulted in the crosslinking of macromolecules and the formation of crystalline iron-containing magnetic nanoparticles in a carbonized polymer matrix. The magnetization of these nanomaterials was found to reach 32 G cm 3 /g in a magnetic field of 2.5 kOe. Transmission electron microscopy (TEM) showed the average size of magnetic nanoparticles to be from 6 to 22 nm. X-ray diffraction studies of the materials revealed a complex composition of the iron-containing magnetic nanoparticles (Fe, Fe 3 C, Fe 2 O 3 , Fe 3 O 4 , etc.).