ON THE MAGNETIC-PROPERTIES OF ETRAMETHYL-4,5-DIHYDRO-1H-IMIDAZOL-1-OXYL-3-OXIDE)

The magnetic properties of -(3,5-diethynylenephenyl)-4,4,5,5-tetrameth yl-4,5- di-hydro-H-1-imidazol-1-oxyl-3-oxide) (4), a polymer with conj ugated backbone and stable radicals in side groups, were investigated between 78 and 300 K with magnetic flux densities B between 0.42 and 1 .32 Tesla. Samples prepared by evaporation of the solvent from the pol ymer solution exhibited normal paramagnetism. Samples precipitated by addition of a nonsolvent (n-hexane) to a polymer solution showed a dep endence of the magnetic mass susceptibility chi(m) on B. This behavior is described by superposition of a paramagnetic term and a temperatur e-independent term depending on B. In addition, an increase of chi(m)T With decreasing temperature T was observed below 150 K.