Ferromagnetic spins interaction in alternating branched polyarylamines

The chemical oxidation of alternating branched polyarylamines leads to the formation of radical cations, the presence of which was manifested by the appearance of new bands in the UV-visible-near infrared spectra. Spins of radical cations can be magnetically coupled. The nutation pulsed-EPR technique was used to determine the multiplicity of spin systems for different oxidant:polymer unit ratios. It was found that spins of polymers oxidized to a radical cation in each conjugated amine segment interact magnetically to form dominant quartet state (S=3/2). Magnetization measurements confirmed the ferromagnetic interaction of spins, returning an exchange integral J=+0.75 meV.