Acta Cryst. (2013). E69, o608
[ doi:10.1107/S1600536813007836 ]
Abstract: The title compound, C13H2F10N2O, has been previously described in the space group Pbca with Z = 8 [Jai-nhuknan et al. (1997). Acta Cryst. C53, 455-457]. The current P212121 polymorph was obtained from a tetrahydrofuran solution. The pentafluorophenyl rings make dihedral angles of 50.35 (6) and 54.94 (6)° with the urea fragment, in close accord with those reported for the first polymorph. In the crystal, both of the N-H groups donate H atoms to the same carbonyl O atom, forming a one-dimensional molecular array along the a axis. There are close contacts between perfluorophenyl C atoms within the array [3.228 (3) Å] and halogen bonds are also observed between the arrays [FF = 2.709 (2) and 2.7323 (18) Å].
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