Hyperfine structure in the EPR spectra of an organometallic magnet based on doped cobalt phthalocyanine

By doping cobalt phthalocyanine with sodium atoms a compound has been synthesized with the formula Na1.7[(CoPc)0.11(H2Pc)0.89], where Pc  C32H16N8. The compound has two kinds of spin carriers: Co2+ ions and electrons which were transferred from sodium atoms to the conjugated ring of the phthalocyanine molecule. The temperature dependence of the magnetization reveals that below 30 K the compound behaves as a magnet. Hyperfine structure of the EPR spectrum is observed above the magnetic ordering temperature.