PREPARATION AND CRYSTAL-STRUCTURE OF C-60S-16

A new fullerene-containing van der Waals-compound, C60S16, has been synthesized and its crystal structure determined from single-crystal X-ray diffraction data collected at room temperature. The compound is monoclinic, space group C 2/c with alpha = 20.867(4) angstrom, b = 21.062(4) angstrom, c = 10.508(2) angstrom, beta = 111.25(7)degrees and four formula units per cell. The C60 molecules form a three-dimensional framework with one-dimensional channels along c which contain crown-shaped S8 rings. The structure has been determined by direct methods and has been refined to atomic resolution on the C60 molecule. The two independent C-C bond distances, averaged under the idealized point symmetry of the ''free'' C60 molecule, amount to 1.340(8) angstrom and 1.448(8) angstrom, corresponding to a ''bond alternation'' as large as 0.108(8) angstrom. The bond lengths are compared with the results of theoretical calculations of the molecular structure of C60 as well as with bond lengths from various experimental sources.