HIGH-RESOLUTION C-13 NMR-STUDIES OF ONE-DIMENSIONAL AND 2-DIMENSIONALPOLYMERIZED C-60 UNDER HIGH-PRESSURE

We report on C-13 NMR measurements of orthorhombic one-dimensional and rhombohedral two-dimensional polymers of C-60 obtained under high pre ssure. The obtained C-13 MAS NMR spectrum of the orthorhombic polymer shows two resonances at 146 ppm and 73.5 ppm, and the one of the rhomb ohedral polymer presents six isotropic lines at 149.1, 147.9, 145.2, 1 39.6, 134.8 and 73.5 ppm. The static distortion of the C-60 molecules induced by the transformation under pressure must be at the origin of the observed inequivalent carbons in both systems. The C-13 NMR linesh ape simulation of the obtained spectra are compatible with the suggest ed polymeric structures where the C-60 molecules are connected by [2 2] cycloadditions. (C) 1997 Elsevier Science Ltd.