Crystal structure of 3,6-bis(4-biphenylyl)pyrrolo[3,4-c]pyrrole-1,4-dione, C30H20N2O2

Abstract

Source of materialThe title compound was obtained from CIBA Specialty Chemicals. The sample was purified by sublimation at about 620 K, using a two-zone furnace [1]. After 60 h, a number of red platelet crystals were obtained. Experimental detailsThe quality of the crystal studied was not sufficiently high, so that only 45% of the measured reflections could be considered as observed (/obs > 3a(/ 0 bs))· This is also reflected in the final relative high Λ-values. DiscussionDiketopyrrolopyrrole (abbreviated to DPP) pigments are industrially important red pigments based on the novel diketopyrrolopyrrole chromophore [2]. DPPs are also used as colorants for imaging areas as well as a color filter for LCD applications. Up to now, five DPP-derivatives are on the market and most of their structures have already been analyzed [3][4][5][6]. The title compound (BP-DPP) is characterized by an extremely large bathochromic shift upon crystallization as compared with other DPP analogues.The present structure analysis has therefore been carried out in order to clarify the electronic structure of BP-DPP. As shown in the figure, the molecule is deformed as characterized by molecular symmetry of Ci. The two phenyl rings on each side of the heterocyclic ring system are twisted asymmetrically in opposite directions. In addition, the heterocyclic ring system is not entirely planar, but is folded in the middle with a dihedral angle of 175.7°. Due to this deformed structure, a dipole moment of about 0.18 D appears perpendicular to the molecular plane. The molecules are arranged in a fashion "bricks in a brick wall", just like J-aggregates in cyanine dyestuffs [7]. There are two kinds of stacking columns: one is composed of the molecules with an upward dipole moment while the neighboring column comprises the molecules with a downward dipole moment. The polar molecules are stacked pairwise so as to reduce the electrostatic energy. On the other hand, on the molecular plane along the a axis, there are chains of intermolecular hydrogen bonds between the NH group of one molecule and the O atom of the neighboring one. This forms a two-dimensional hydrogen bond network as found in all DPP pigments [3][4][5][6]. Details of the correlation between the crystal and electronic structures are given in references [8,9].

Crystal structure of 5,12-dihydro-2,9-dimethylquino[2,3-b]acridine-7,14- dione, C22H16N2O2, at 123 Κ

“…The molecule is entirely planar and belongs to the point group of C,·. There are intermolecular hydrogen bonds between the NH group of one molecule and the O atom of the neighboring one, forming a two-dimensional hydrogen bond network as found in the β phase of unsubstituted quinacridone [5] and also in all pyrrolopyrrole pigments [6][7][8][9][10][11][12][13][14][15]. Each molecule is hydrogen-bonded to two molecules.…”

Crystal structure of 3-[4-(1,1-dimethylethyl)phenyl]-2,5-dihydro-6- phenylpyrrolo[3,4-c]pyrrole-1,4-dione, C22H20N2O2, at 93 Κ

“…As shown in the figure, the molecule is characterized by the C1 symmetry. The two phenyl rings on each side of the heterocyclic ring system are twisted asymmetrically in opposite directions ("propeller type"): about 11.1 ° at the C10-C13 bond and about 14.2° at the C4-C7 bond as in the case of /m-butylphenyl derivative (TB-DPP) [6] and biphenyl derivative (BP-DPP) [8], On the other hand, the twisting of the phenyl rings takes place in the same direction in other DPPs (C, symmetry) [4,5,7]. In addition, the heterocyclic ring system is not entirely planar, but is folded in the middle with a dihedral angle of 177.7° as in TB-DPP and BP-DPP, while it is completely planar in other DPPs.…”

“…On the (a,c) molecular plane, there are chains of intermolecular hydrogen bonds between the NH group of one molecule and the O atom of the neighboring one. This forms a two-dimensional hydrogen bond network as found in all DPP pigments [4][5][6][7][8] and causes the very good thermal and solvent resistance of the hydrogen bonded DPP pigments. …”

Crystal structure of 3,6-diphenylpyrrolo[3,4-c]pyrrole-1,4-dione—3,6- bis(4-tert-butylphenyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (1:1), (C18H12N2O2) · (C26H28N2O2)

“…bond network as found in all pyrrolopyrrole pigments [4,5,[7][8][9][10] and causes the very good thermal and solvent resistance of the hydrogen bonded DPP pigments. In addition, the t-butyl group of one BTB-DPP molecule faces the phenyl ring of the neighboring DPP molecule in the lattice plane (bottom figure) as observed exactly in MTB-DPP.…”