STATIC DISORDER AND PACKING IN 2 ORTHORHOMBIC CRYSTAL-STRUCTURES OF FULLERENE INCLUSION-COMPOUNDS

Two orthorhombic fullerene crystal structures, C-60 x 1.5 CS2 and C-70 x [(C6H4)CH3)(2)], have been studied by single crystal X-ray diffract ion. These fullerene crystal structures are similar in that they both crystallize in the same orthorhombic space group, that they both have static disorder properties and that their crystal packing is rather al ike, although C-70, is less symmetric than C-60. Both structures were solved by Patterson syntheses, assuming the almost spherical fullerene units would behave like a massive atom, Solutions for the two crystal lographically independent molecular centres of each structure were obt ained easily, Rigid body refinements with SHELX93 and subsequent diffe rence syntheses allowed the identification of a total of four disorder orientations for each of the two C-60 units having two molecular cent res in common, Following the same procedure for the C-70 structure led to two disorder orientations for each of the fullerene centres. In th e orthorhombic lattices the coordination number is reduced to 10 for b oth independent C-60 units and to 9 and 10 for C-70, being otherwise 1 2 for the closely packed fullerenes.