Spin exchange between paramagnetic probes inside graphite oxide

Heisenberg spin exchange among paramagnetic species in acetonitrile intercalated into graphite oxide was studied. It was found that spin exchange in between the oxidized graphene planes is strongly hindered, and spin-exchange broadening of EPR spectra has not been observed both for particles of the same nature (TEMPO -TEMPO) and for particles of different types (TEMPO-Ni2+). The addition of nickel ions into the "graphite oxide - CH3CN" system led to the absence of the char-acteristic phase transformation of the high-temperature swelled graphite oxide to the low-temperature one.