ELECTRON-TRANSFER AT LANTHANUM ENDOHEDRAL FULLERENES

The aim of this contribution is to study lanthanum containing fulleren es produced and treated under different conditions. The work was done using solid soot extract giving poorly resolved ESR spectra or separat ed lanthanofullerenes in solution showing well resolved ESR spectra. E SR experiments in connection with the mass spectrometry give informati on on the electronic states due to the electron transfer from the endo hedral metal to the fullerene cage and the influence of oxygen on endo hedral lanthanofullerene. The analysis of ESR spectra indicates the pr esence of up to nine octets of lanthanum containing fullerenes. These species have different stabilities. Furthermore, a very narrow single ESR line in the lanthanofullerene spectrum was detected having a linew idth Delta B = 0.008 mT and a g-factor 2.0025. The electron transfer t o the endohedral La@C-82 molecule studied by voltammetry and electroch emical in situ ESR experiments is described The interaction of the lan thanofullerene with oxygen in solution is alsb studied. In different s olvents the influence of oxygen on line broadening in the ESR spectra of La@C-82 was observed.