Synthesis and Physical Properties of New Metallic Compound Li_xC₆₀(THF)_y

Electrocrystallization of C₆₀ in chlorobenzene and lithium tetraphenylborate in THF efficiently produced the new metallic species Li_xC₆₀(THF)_y; the ESR spectra show clearly the existence of a typical broad signal due to the C₆₀ anion radical. The change of the intensity of the ESR signal corresponds to the metal-insulator transition at 150 K, and the ¹³C and ⁷Li solid-state NMR spectra are also reported, as shown in Fig. 1.

Fig. 1. Solid-state (a) ¹³C and (b) ⁷Li NMR spectra of Li_xC₆₀(THF)_y crystals.