QENS AND NMR INVESTIGATION OF REORIENTATIONAL DYNAMICS IN C61H2

Protonated and deuterated samples of the dihydrofulleroid C61H2 [Suzuk i T. Q. (''Chan'') Li, Khemani K. C. and Wudl F., J. Am. Chem. Soc. 11 4, 7301 (1992)], have been synthesized and characterized by C-13, H-1, H-2 high resolution NMR, HPLC, TGA, DSC and mass spectrometry. Its mo lecular dynamics have been studied in the solid state with NMR and Qua si-elastic Neutron Scattering. The unitary interpretation of the resul ts obtained from these two techniques gives a picture of the molecular reorientation in this system which is completely different from that observed in the rotor phase of C60, where the molecules are described to reorient isotiopically, and should be compared to C60O [Vaughan G. B. M., Heiney P. A., Cox D. E., McGhie A. R., Jones D. R., Strongin R. M., Cichy M. A. and Smith III A. B., Chem. Phys. 168, 185 (1992)]. In C61 H-2 the molecular units rotate almost uniaxially around the line joining the centre of the molecule and the methylene carbon. Much slow er reorientation of the axis itself among different lattice directions also takes place.