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Physical Sciences and Mathematics

University of Wollongong

Australian Institute for Innovative Materials - Papers

2007

4

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5-Methoxy-2-Methyl-4-Nitro-1-Phenyl-1h-Imidazole, Pawel Wagner, Maciej Kubicki Jan 2007

5-Methoxy-2-Methyl-4-Nitro-1-Phenyl-1h-Imidazole, Pawel Wagner, Maciej Kubicki

Australian Institute for Innovative Materials - Papers

The title compound, C11H11N3O3, contains two planar fragments, viz. the imidazole and phenyl rings. These rings are significantly twisted with respect one to another, with a dihedral angle of 63.99 (8)°. The nitro group is almost coplanar with the imidazole plane, while the methoxy group is almost perpendicular to it [the C—C—O—C torsion angle is 65.1 (4)°]. In spite of this, there is a short C(methoxy)—H...O(nitro) contact that might be regarded as an intramolecular hydrogen bond. Weak intermolecular C—H...N(imidazole) and C—H...O(nitro) hydrogen bonds create quite a complicated network that consists of …


2-Methyl-4-Nitro-1-(3-Pyridyl)-1h-Imidazole, Maciej Kubicki, Pawel Wagner Jan 2007

2-Methyl-4-Nitro-1-(3-Pyridyl)-1h-Imidazole, Maciej Kubicki, Pawel Wagner

Australian Institute for Innovative Materials - Papers

The imidazole and pyridine rings in the title compound, C9H8N4O4, are twisted with respect to one another, with a dihedral angle of 48.30 (4)°. The nitro group is almost coplanar with the imidazole plane. The crystal packing involves some weak C—H...N and C—H...O hydrogen bonds, of which the strongest, between the imidazole CH group and a nitro O atom [H...O 2.396 (15) Å], forms a centrosymmetric dimer.


Crystal Packing Of Two 5-Substituted 2-Methyl-4-Nitro-1h-Imidazoles, Pawel Wagner, Krzysztof Swierczek, Maciej Kubicki Jan 2007

Crystal Packing Of Two 5-Substituted 2-Methyl-4-Nitro-1h-Imidazoles, Pawel Wagner, Krzysztof Swierczek, Maciej Kubicki

Australian Institute for Innovative Materials - Papers

Infinite chains connected by N-H...N hydrogen bonding form the primary packing motif in two closely related 4-nitroimidazole derivatives, viz. 5-bromo-2-methyl-4-nitro-1H-imidazole, C4H4BrN3O2, (I), and 2-methyl-4-nitro-1H-imidazole-5-carbonitrile, C5H4N4O2, (II). These chains are almost identical, even though in (II) there are two symmetry-independent molecules in the asymmetric unit. The differences appear in the interactions between the chains; in (I), there are strong C-Br...O halogen bonds, which connect the chains into a two-dimensional grid, while in (II), the cyano group does not participate in specific interactions and the chains are only loosely connected into a three-dimensional structure.


Two Different Modes Of Halogen Bonding In Two 4-Nitroimidazole Derivatives, Maciej Kubicki, Pawel Wagner Jan 2007

Two Different Modes Of Halogen Bonding In Two 4-Nitroimidazole Derivatives, Maciej Kubicki, Pawel Wagner

Australian Institute for Innovative Materials - Papers

In the crystal structures of the two imidazole derivatives 5-chloro-1,2-dimethyl-4-nitro-1H-imidazole, C5H6ClN3O2, (I), and 2-chloro-1-methyl-4-nitro-1H-imidazole, C4H4ClN3O2, (II), C—Cl...O halogen bonds are the principal specific interactions responsible for the crystal packing. Two different halogen-bond modes are observed: in (I), there is one very short and directional C—Cl...O contact [Cl...O = 2.899 (1) Å], while in (II), the C—Cl group approaches two different O atoms from two different molecules, and the contacts are longer [3.285 (2) and 3.498 (2) Å] and less directional. …


2-Methyl-4-Nitro-1-(4-Nitrophenyl)-1h-Imidazole, Pawel Wagner, Maciej Kubicki Jan 2007

2-Methyl-4-Nitro-1-(4-Nitrophenyl)-1h-Imidazole, Pawel Wagner, Maciej Kubicki

Australian Institute for Innovative Materials - Papers

In the title compound, C10H8N4O4, two planar fragments, viz. the imidazole and nitrophenyl rings, are tilted at a dihedral of 57.89 (7)°. The nitro groups are twisted with respect to the neighbouring ring planes; the dihedral angle is 7.0 (3)° for imidazole and 9.68 (8)° for benzene. The crystal structure consists of centrosymmetric dimers generated by C—H...O hydrogen bonds, which are connected by C—H...N hydrogen bonds into rows along the [001] direction. The neighbouring rows are connected via C—H...O interactions into a two-dimensional network in the bc plane.


2-Methoxy-1-Methyl-4-Nitro-1h-Imidazole, Maciej Kubicki, Pawel Wagner Jan 2007

2-Methoxy-1-Methyl-4-Nitro-1h-Imidazole, Maciej Kubicki, Pawel Wagner

Australian Institute for Innovative Materials - Papers

The molecule of the title compound, C5H7N3O3, is approximately planar. The maximum deviation from the least-squares plane calculated for all non-H atoms is 0.054 (2) Å. The dihedral angles between the mean plane of the imidazole ring [planar within 0.0017 (6) Å] and the planes of the nitro and methoxy groups are 2.9 (1) and 1.2 (1)°, respectively. The molecules are held together by weak C—H...N and C—H...O interactions and by van der Waals forces.


Ring Transformations In The Reactions Of 1,4-Dinitropyrazole With N-Nucleophiles, Rafal Jedrysiak, Marcin Sawicki, Pawel Wagner, Jerzy Suwinski Jan 2007

Ring Transformations In The Reactions Of 1,4-Dinitropyrazole With N-Nucleophiles, Rafal Jedrysiak, Marcin Sawicki, Pawel Wagner, Jerzy Suwinski

Australian Institute for Innovative Materials - Papers

The reactions of 1,4-dinitropyrazole with primary amines, hydrazines, hydroxylamine and amidines were studied. 1,4-Dinitropyrazole in these reactions served as the synthetic equiv. of nitromalonaldehyde. The reaction of dinitropyrazole with primary arylhydrazines proved to be a convenient approach to the synthesis of 1-aryl-4-nitropyrazoles.