C60 1,1,2,2-tetrachloroethylene tetrasolvate

In the title complex, C60·4C2Cl4, the C60 molecule is located on an inversion centre and there are two tetrachloroethylene (TCE) molecules in the asymmetric unit. Both TCE molecules show positional disorder, with occupancy ratios of 0.75:0.25 and 0.56:0.44. Four fullerene C atoms form short contacts [3.208 (17) and 3.223 (17) Å] with the centres of the TCE double bonds, indicating that C60–solvent interactions are largely π–π in nature.

In the title complex, C 60 Á4C 2 Cl 4 , the C 60 molecule is located on an inversion centre and there are two tetrachloroethylene (TCE) molecules in the asymmetric unit. Both TCE molecules show positional disorder, with occupancy ratios of 0.75:0.25 and 0.56:0.44. Four fullerene C atoms form short contacts [3.208 (17) and 3.223 (17) Å ] with the centres of the TCE double bonds, indicating that C 60 -solvent interactions are largelyin nature. inter-pentagonal bond distances are in the range 1.3947 (17)

Related literature
Experimental C 60 sample was purchased from Sigma-Aldrich and used as received. The solvents for crystallization, 1,1,2,2-tetrachloroethylene (TCE) and methanol were of purity >99% and were purchased from E. Merck (Germany). Crystals of the C 60 .
4(CCl 4 ) were grown by diffusion of methanol into a solution of C 60 in TCE over a period of five days. Upon removal from the mother liquor the crystals were unstable anad therefore were mounted at 0°C.

Refinement
The C 60 molecule was refined without any restraints. Both TCE molecules were disordered and showed two approximately perpendicular orientations with overlapping Cl atoms (the ratio of occupancies 0.75:0.25 and 0.56:0.44). Since one of the disordered TCE molecules showed occupancies very close to 0.75 and 0.25 these values were fixed at the final stages of the refinement. The restraints were imposed on C-C and C-Cl bond lengths of the TCE molecules and anisotropic displacement parameters of C31A, C32A and C34A atoms. The residual peak of 1.25 e Å −3 is located at 1.06 Å from the C5 atom of C 60 indicating that in addition to large librational motion the C 60 molecule can be also partially disordered. The high residual values, R1=0.105 and wR1=0.259 are most probably due to disorder of the TCE and C 60 molecules.
supplementary materials sup-2 Figures Fig. 1. ORTEP diagram of the title compound showing 50% probability displacement ellipsoids. Labels for C 60 were omitted. The TCE molecules in minor occupancies are not shown. Symmetry code for the atoms not from the asymmetric unit(_2): 2 − x, −y, −z).   Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > 2sigma(F 2 ) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.