Crystal structures of 5,5'-bis(-hydroxy-methyl)-3,3'-biisoxazole and 4,4',5,5'-tetrakis-(hydroxy-methyl)-3,3'-biisoxazole.
ABSTRACT: The mol-ecular structure of 5,5'-bis(-hydroxy-methyl)-3,3'-biisoxazole, C8H8N2O4 (1), is composed of two trans planar isoxazole rings [r.m.s deviation = 0.006?(1)?Å], each connected with a methyl hydroxyl group. Similarly, the structure of 4,4',5,5'-tetrakis-(hydroxy-methyl)-3,3'-biisoxazole, C10H12N2O6 (2), is composed of two planar isoxazole rings [r.m.s. deviation = 0.002?(1)?Å], but with four hydroxymethyl groups as substituents. Both mol-ecules sit on a center of inversion, thus Z' = 0.5. The crystal structures are stabilized by networks of O-H?N [for (1)] and O-H?O hydrogen-bonding inter-actions [for (2)], giving rise to corrugated supra-molecular planes. The isoxazole rings are packed in a slip-stacked fashion, with centroid-to-centroid distances of 4.0652?(1)?Å for (1) (along the b-axis direction) and of 4.5379 (Å) for (2) (along the a-axis direction).
Project description:The mol-ecular structure of the title energetic compound, C<sub>8</sub>H<sub>6</sub>N<sub>4</sub>O<sub>8</sub>, is composed of two planar isoxazole rings and two near planar alkyl-nitrate groups (r.m.s deviation = 0.006?Å). In the crystal, the mol-ecule sits on an inversion center, thus <i>Z</i>' = 0.5. The dihedral angle between the isoxazole ring and the nitrate group is 69.58?(8)°. van der Waals contacts dominate the inter-molecular inter-actions. Inversion-related rings are in close slip-stacked proximity, with an inter-planar separation of 3.101?(3)?Å [centroid-centroid distance = 3.701?(3)?Å]. The measured and calculated densities are in good agreement (1.585 <i>versus</i> 1.610?Mg?m<sup>-3</sup>).
Project description:In energetic materials, the crystal density is an important parameter that affects the performance of the material. When making ionic energetic materials, the choice of counter-ion can have detrimental or beneficial effects on the packing, and therefore the density, of the resulting energetic crystal. Presented herein are a series of five ionic energetic crystals, all containing the dianion 5,5'-(3,3'-bi[1,2,4-oxa-diazole]-5,5'-di-yl)bis-(1H-tetra-zol-1-olate), with the following cations: hydrazinium (1) (2N2H5+·C6N12O42-), hydroxyl-ammonium (2) 2NH4O+·C6N12O42- [Pagoria et al.. (2017). Chem. Heterocycl. Compd, 53, 760-778; included for comparison], di-methyl-ammonium (3) (2C2H8N+·C6N12O42-), 5-amino-1H-tetra-zol-4-ium (4) (2CH4N5+·C6N12O42-·4H2O), and amino-guanidinium (5) (2CH7N4+·C6N12O42-). Both the supra-molecular inter-actions and the sterics of the cation play a role in the density of the resulting crystals, which range from 1.544 to 1.873 Mg?m-1. In 5, the tetra-zolate ring is disordered over two positions [occupancy ratio 0.907?(5):0.093?(5)] due to a 180° rotation in the terminal tetra-zole rings.
Project description:In the title mol-ecule, C14H17NO, the 5,5-di-methyl-cyclo-hex-2-enone moiety is attached to an aniline group, the dihedral angle subtended [54.43?(3)°] indicating a significant twist. The hexaneone ring has a half-chair conformation with the C atom bearing two methyl groups lying 0.6384?(8)?Å above the plane of the five remaining atoms (r.m.s. deviation = 0.0107?Å). The crystal packing can be described as alternating layers parallel to (-101), which are consolidated by N-H?O hydrogen bonds and C-H?? inter-actions.
Project description:In the title compound, [Cu(2)Cl(4)(C(11)H(16)N(4))](n), the Cu atom is coordinated by two N atoms of two 3,3',5,5'-tetra-methyl-4,4'-methyl-enedipyrazole (H(2)mbdpz) ligands, two bridging Cl atoms and one terminal Cl atom, forming a square-pyramidal geometry. The bridging Cl atoms and the bridging H(2)mbdpz ligands connect the Cu atoms to build up an extended one-dimensional chain. The chains are further connected through N-H?Cl hydrogen bonds to build up a two-dimensional layer in the (011) plane. An inversion centre lies between every pair of adjacent Cu atoms.
Project description:THE TITLE COMPOUND [SYSTEMATIC NAME: 3,3',6,6'-tetra-hydroxy-4,4'-dimethyl-1,1'-bi(cyclo-hexa-3,6-diene)-2,2',5,5'-tetra-one], C(14)H(10)O(8), was isolated from Tremella fuciformis. The mol-ecule has 2 symmetry, with the mid-point of the C-C bond linking the cyclo-hexa-dienedione rings located on a twofold rotation axis. In the mol-ecule, the ring is approximately planar, with an r.m.s. deviation of 0.0093?Å, and the two rings make a dihedral angle of 67.89?(5)°. Inter-molecular O-H?O hydrogen bonding occurs in the crystal structure.
Project description:The mol-ecular skeleton of the title mol-ecule, C(11)H(9)NO(3), is approximately planar (r.m.s. deviation = 0.0056?Å); the two rings form a dihedral angle of 6.5?(1)°. In the crystal structure, inter-molecular O-H?N hydrogen bonds involving the H atom of the hydr-oxy group and the N atom of the isoxazole ring link mol-ecules into chains running along the c axis.
Project description:A planar energetic molecule with high density, 5,5'-dinitramino-3,3'-azo-1,2,4-oxadiazole (4), was obtained by the nitration of 5,5'-diamino-3,3'-azo-1,2,4-oxadiazole using 100?% nitric acid. In addition, selected nitrogen-rich salts were prepared. Of them, the neutral compound 4 and its hydroxylammonium salt, 6, were further confirmed by single-crystal X-ray diffraction. Physicochemical and energetic properties including density, thermal stability, and sensitivity were investigated. The energetic performance from the calculated heats of formation and experimental densities indicates that many of them have potential applications as energetic materials.
Project description:The mol-ecular structure of the title compound, C(28)H(20)N(4)O(6), consists of three fused six-membered rings (A,B,C) and one five-membered ring (D). The latter is linked to an isoxazole ring (E) via a methyl-ene unit. A 4-nitro-phenyl substituent (F) is attached to the isoxazole. The fused five and six-membered rings (C,D) are almost coplanar with an r.m.s. deviation of 0.0345?Å and make a dihedral angle of 9.40?(8)° with ring A. The isoxazole and 4-nitro-phenyl rings (E,F) are also almost coplanar with the imidazole and the fused adjacent ring (C,D), forming a dihedral angle of 11.4?(6)°. The crystal packing displays inter-molecular C-H?O hydrogen bonding. An intra-molecular C-H?O inter-action also occurs.
Project description:In the title compound, C29H24N2, the C=N bond of the central imine group adopts an E conformation. The dihedral angles between the mean plane of the essentially planar carbazole ring system [r.m.s. deviation = 0.039?(2)?Å] and the two phenyl rings of the 3,3-di-phenyl-allyl-idene unit are 75.9?(1) and 64.6?(1)°. In the crystal, mol-ecules are linked by C-H?? inter-actions, forming a three-dimensional supra-molecular network.
Project description:The title compound, C(15)H(17)O(6)P, was obtained from a reaction of 4-methyl-7-hy-droxy-coumarin and 2-chloro-5,5-dimethyl-1,3,2-dioxaphosphinane 2-oxide. There are two mol-ecules in the asymmetric unit in which the benzopyran ring system is almost planar [r.m.s. deviation for each molecule = 0.003?Å]. In the crystal, C-H?O hydrogen bonds and ?-? stacking inter-actions [with centroid-centroid distances of 3.743?(3) and 3.727?(3)?Å] link the two mol-ecules. The dioxaphospho-rinane ring adopts a chair conformation in both asymmetric molecules.