Separation and characterization of ESR-active lanthanum endohedral fullerenes

Chlorobenzene was used as an efficient eluent in the two-stage high-perform ance liquid chromatography (HPLC) separation of the isomers of lanthanum en dohedral fullerenes (La@C-n). The resultant yields of purification for some La@C-n by two-stage HPLC with chlorobenzene were much higher than that wit h toluene. La@C-76, La@C-80-I, II, and La@C-84-I, II were purified for the first time and La@C-78 was obtained in its partially purified form at the p urity of approximately 60%, and their visible-near infrared (vis-NIR) and e lectron spin resonance (ESR) spectra were reported. Consequently, all speci es of La@C-n with even number n from 76 to 90 were detected and their ESR p arameters were determined.