Na4C60: an alkali-intercalated two-dimensional-conducting polymer

The View the MathML source magic angle spinning NMR spectrum obtained on the Na4C60 polymer shows several isotropic resonances accompanied by side bands in the region from 100 to 250 ppm, and a single line at View the MathML source. We attribute the former group of lines to inequivalent sp2 carbons on the C60 molecules, and the latter line to sp3 carbons of the single inter-ball bondings. The electron spin resonance results reveal a metallic behaviour of the Na4C60 compound, in contrast to the insulating A4C60 (A=K, Rb, Cs) fullerides. We also present Raman studies of the Na4C60 polymer, which provide clear evidence for charge transfer of four electrons per C60 in the major portion of the sample under consideration, in agreement with X-ray data.