The title compound, C(16)H(6)N(6), is a polymorph of the previously reported structure [Kozlov & Goldberg (2008 ▶). Acta Cryst. C64, o498-o501]. Unlike the previously reported monoclinic polymorph (space group P2(1)/c, Z = 8), the title compound reveals ortho-rhom-bic symmetry (space group Pnma, Z = 4). The mol-ecule shows crystallographic mirror symmetry, while the previously reported structur...

The continued development of novel drugs, proteins, and advanced materials strongly rely on our ability to self-assemble molecules in solids with the most suitable structure (polymorph) in order to exhibit desired functionalities. The search for new polymorphs remains a scientific challenge, that is at the core of crystal engineering and there has been a lack of effective solutions to this prob...

In the title compound, C12H8N2O5, the aromatic rings are inclined to one another by 56.14 (7)°. The nitro groups are inclined by to the benzene rings to which they are attached by 3.86 (17) and 9.65 (15)°. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming a three-dimensional structure. The title compound is a new monoclinic polymorph, crystallizing in space group P21/c. The...

The title compound, C17H13ClO, is the second monoclinic polymorph to crystallize in the space group P21/c. The first polymorph crystallized with two independent mol-ecules in the asymmetric unit [Bolognesi et al. (1975 ▸). Acta Cryst. A31, S119; Z' = 2; no atomic coordinates available], whereas the title compound has Z' = 1. In the title polymorph, the dihedral angle between the plane of the be...

A new polymorph of 2-(benzotriazol-2-yl)acetic acid, C(8)H(7)N(3)O(2), crystallizes in the space group C2/c (Z = 8). The non-planar mol-ecule has a synplanar conformation of the carb-oxy group. The crystal structure features helices parallel to the b axis sustained by O-H⋯N hydrogen bonding which are similar to those in the known polymorph [Giordano & Zagari (1978 ▶). J. Chem. Soc. Perkin Trans...

The crystal structure of a second polymorph of sodium di-hydrogen citrate, Na(+)·H2C6H5O7 (-), has been solved and refined using laboratory X-ray powder diffraction data, and optimized using density functional techniques. The powder pattern of the commercial sample used in this study did not match that corresponding to the known crystal structure [Glusker et al. (1965). Acta Cryst. 19, 561-572;...

The asymmetric unit of a second polymorph of the title compound, C(9)H(4)F(6)O(2), contains five independent mol-ecules, which form hydrogen-bonded O-H⋯O dimers about inversion centers. The most significant structural difference between this structure and that of the first polymorph [Tobin & Masuda (2009 ▶). Acta Cryst. E65, o1217] is the hydrogen-bonded, dimeric orientation of the carb-oxy-lic...

The title compound, C(12)H(13)N(5)O(2)S {systematic name: ethyl N-[N-(3-phenyl-1H-1,2,4-triazol-5-yl)carbamothio-yl]carbamate}, is a monoclinic polymorph (space group P2(1)/c) which crystallizes with three similar independent mol-ecules in the asymmetric unit. The triazole ring makes dihedral angles of 6.6 (2), 8.4 (2) and 10.6 (2)° with the phenyl ring in the three independent molecules. The s...

The title compound, (C6H11)3PS (systematic name: tri-cyclo-hexyl-λ5-phosphane-thione), is a triclinic (P-1, Z' = 1) polymorph of the previously reported ortho-rhom-bic form (Pnma, Z' = 1/2) [Kerr et al. (1977 ▸). Can. J. Chem. 55, 3081-3085; Reibenspies et al. (1996 ▸). Z. Kristallogr. 211, 400]. While conformational differences exist between the non-symmetric mol-ecule in the triclinic polymor...

THE TITLE COMPOUND [SYSTEMATIC NAME: 7-bromo-5-(2-chloro-phen-yl)-1H-1,4-benzodiazepin-2(3H)-one] (β-polymorph), C(15)H(10)BrClN(2)O, has been obtained via cryomodification of the known α-polymorph of phenazepam [Karapetyan et al. (1979 ▶). Bioorg. Khim.5, 1684-1690]. In both polymorphs, the mol-ecules, which differ only in the dihedral angles between the aromatic rings [75.4 (2)° and 86.2 (3)°...