STRUCTURES OF 3,6-DIPHENYLPYRROLO[3,4-C]PYRROLE-1,4-DIONE AND 2,5-DIMETHYL-3,6-DIPHENYLPYRROLO[3,4-C]PYRROLE-1,4-DIONE

Crystal data for 3,6-diphenylpyrrolo[3,4-c]pyrrole-1, 4-dione (DPP) are: C18H12N2O2, M(r) = 288.310, triclinic, P1BAR, a = 3.817 (1), b = 6.516 (1), c = 13.531 (2) angstrom, alpha = 93.11 (1), beta 86.97 (1), gamma = 95.02 (1)-degrees V = 334.3 (2) angstrom3, Z = 1, D(x) = 1.43, D(m) = 1.410 Mg m-3, graphite-monochromated Cu Kalpha radiation, lambda = 1.5418 angstrom, mu = 0.73 mm-1, F(000) = 150, T = 293 K, R - 0.059 for 1076 reflections. Crystal data for 2,5-dimethyl-3,6-diphenylpyrrolo[3,4-c]pyrrole-1, 4-dione (DM-DPP) are: C20H16N2O2, M(r) = 316.359, orthorhombic, Pbcn, a = 11.666 (1), b 12.003 (1), c = 10.779 (1) angstrom, V = 1509.4 (2) angstrom3, Z = 4, D(x) = 1.392, D(m) = 1.388 Mg m-3, graphite-monochromated Cu Kalpha radiation, lambda = 1.5418 angstrom, mu = 0.54 mm-1, F(000) = 522, T 293 K, R = 0.054 for 1470 reflections. The DPP and DM-DPP molecules, both of which belong to the point group C(i), are not entirely planar. The phenyl rings are twisted in the same direction; out of the plane of the planar heterocyclic system by 7(1)-degrees in DPP and by 31 (1)-degrees in DM-DPP. The DPP molecules align in nearly the same molecular plane and parallel to each other due to intermolecular hydrogen bonding. By contrast, the DM-DPP molecules are arranged in a herringbone fashion along the stacking axis.