Synthesis, reactivity, structure and electronic properties of [N(CH3)4]C60· 1.5thf: fullerides with simple hexagonal packing

Abstract

The preparation of [N(CH₃)₄]C₆₀· 1.5thf and characterisation of its electronic properties, using susceptibility, EPR and ¹³C MAS NMR measurements, is reported. X-Ray powder diffraction shows a simple hexagonal stacking sequence of close-packed C₆₀ layers, with cations and solvent molecules located in the trigonal-prismatic sites. The electronic properties are consistent with narrow-band metallic behaviour at high temperature. A transition in susceptibility and EPR measurements is seen between 200 and 230 K. A similar synthesis affords a C₆₀^2– compound with the same simple hexagonal fulleride packing.