Characterization of Ce@C_(82) and Its Anion

摘要

Ce@C_(82) is isolated by high-performance liquid chromatography (HPLC) and the cage symmetry is determined as C_(2v) by measuring the ~(13)C NMR spectra of its anion. The ~(13)C NMR peaks of [Ce@C_(82)]-~ show temperature-dependent shifts ascribed to the f electron remaining on the Ce atom. Both Ce@C_(82) and [Ce@C_(82)]~- are silent in electron spin resonance spectroscopy (ESR) because of the highly anisotropic g matrix as well as of the fast relaxation process originating from the orbital angular momentum of the f electron. This is the complementary relationship to the observation of the paramagnetic shift in ~(13)C NMR. [Ce@C_(82)]~- has lower stability in air than [La@C_(82)]~-.