Structures of polyfluoroaromatic compounds. V. Crystal structure of perfluorodiphenylacetylene

Abstract

C14Fto is orthorhombic, space group Pbca, with a = 9.59 (1), b = 9.59 (1), c = 27.34 (2) A, Z = 8. The structure was refined to R = 5.25% for 1202 counter amplitudes [I > 2.5a(I)]. The molecule is essentially planar, but its long axis is slightly bent so that the aromatic rings make an in-plane angle of 4 ° with one another. The C-C triple-bond length is 1.198 /~ and the two C(sp)-C(sp 2) lengths average 1.419 /~, (uncorrected for thermal libration). E.s.d.'s are 0.004-0.006 /k for bond lengths and 0-4-0.5 ° for bond angles.

Arene-perfluoroarene interactions in crystal engineering: structural preferences in polyfluorinated tolans

“…In contrast, the crystal structure of pure 2 shows a typical herring-bone packing motif; the molecule has no crystallographic symmetry and a small (2.2u) intramolecular twist of the rings. 35 The structure of pure tolan 1 36 contains two crystallographically non-equivalent molecules, both with inversion centres. One of them is planar, while the other shows the same distortion as in 1:2, with the interplanar distance of 0.20 A ˚.…”

Fluorine nonbonded potential parameters derived from crystalline perfluorocarbons

“…A search of the literature revealed seven perfluorocarbons whose crystal structures had been experimentally well determined by either X-ray or neutron diffraction methods. These crystal structures were: hexafluorobenzene, C6F 6 (Boden, Davis, Stam & Wesselink, 1973;Baharie & Pawley, 1977); octafluorocyclooctatetraene, C8F8 (Laird & Davis, 1982); decafluorobiphenyl, C12F1o (Gleason & Britton, 1976); dodecafluoro-1,2;3,4; 5,6-triethanobenzene, C12F12 (Cobbledick & Einstein, 1976); decafluorodiphenylacetylene, C14E1o (Goodhand & Hamor, 1979); decafluorofluoranthene, C,rFlo (Goodhand & References: (a) Baharie & Pawley (1977); (b) Laird & Davis (1982); (c) Gleason & Britton (1976); (d) Cobbledick & Einstein (1976); (e) Goodhand & Hamor (1979); (.f) Goodhand & Hamor (1981); (g) Cobbledick & Einstein (1977). Hamor, 1981); and tetracosafluorotetrapropanocyclooctatetraene, C20F24 (Cobbledick & Einstein, 1977).…”