Acta crystallographica. Section E, Structure reports online最新文献

The title compound, C11H17BrN2O5, is a de-hydro-amino acid with a C=C bond between the α- and β-C atoms. The amino acid residues are linked trans to each other and there are no strong intra-molecular hydrogen bonds. The torsion angles indicate a non-helical conformation of the mol-ecule. The dipeptide folding is influenced by an inter-molecular N-H⋯O hydrogen bond and also minimizes steric repulsion. In the crystal, mol-ecules are linked by strong N-H⋯O hydrogen bonds, generating (001) sheets. The sheets are linked by weak C-H⋯O and C-H⋯Br bonds and short Br⋯Br [3.4149 (3) Å] inter-actions.

In the title compound, C35H31N3O5S, the piperidine ring adopts an envelope conformation, with the methine C atom as the flap, and the pyran ring adopts a sofa conformation. The mean planes of these two rings are almost normal to one another, making a dihedral angle of 85.96 (5)°. The two phenyl rings, one attached to the pyrazole ring and the other to the pyran ring, are inclined to one another by 65.41 (11)°. They are inclined to the mean planes of the rings to which they are attached by 12.59 (11) and 70.09 (9)°, respectively. There is an intra-molecular C-H⋯π inter-action involving the tosyl-ate methyl group and the phenyl ring attached to the pyrazole ring. In the crystal, mol-ecules are linked by C-H⋯π inter-actions, forming ribbons parallel to (10-2). The ribbons are linked by slipped parallel π-π inter-actions involving inversion-related pyrazole rings [inter-centroid distance = 3.672 (2) Å], forming slabs parallel to (001). A preliminary report of this structure has been published [Bakthadoss et al. (2014 ▶). Eur. J. Org. Chem. pp. 1505-1513].

The mol-ecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å), with the planes of the two pyridine rings inclined to one another by 5.51 (7)°. The oxime group is syn to the amide group, probably due to the formation of an intra-molecular N-H⋯N hydrogen bond that forms an S(6) ring motif. In the crystal, mol-ecules are linked by pairs of bifurcated O-H⋯(O,N) hydrogen bonds, forming inversion dimers. The latter are linked via C-H⋯O and C-H⋯N hydrogen bonds, forming sheets lying parallel to (502). The sheets are linked via π-π stacking inter-actions [inter-centroid distance = 3.7588 (9) Å], involving the pyridine rings of inversion-related mol-ecules, forming a three-dimensional structure.

In the title compound, C9H15NO2, the piperidine ring exhibits a chair conformation. The butane-dione subunit exhibits a conformation with the ketone C atom in an eclipsed position with respect to the amide carbonyl group. In the crystal, a two-dimensional layered arrangement is formed by hydrogen bonds of the C-H⋯O type between the methyl group and the exocyclic methyl-ene unit as donor sites and the amide carbonyl O atom as the acceptor of a bifurcated hydrogen bond. These layers are oriented parallel to the ab plane.

The title mol-ecular salt, C8H13N2 (+)·Br(-), crystallizes with two independent 3-amino-pyridinium cations and two bromide anions in the asymmetric unit (Z' = 2). In the pyridine ring, the N atom is alkyl-ated by a propyl group. The dihedral angle between the mean planes of the pyridinium ring and the propyl group is 84.84 (2)° in cation A, whereas the corresponding angle is 89.23 (2)° in cation B. In the crystal, the anions and cations are linked via N-H⋯Br and C-H⋯Br hydrogen bonds, forming chains propagating along [100].

In the title compound, [ReBr(C13H10N4)(CO)3], the Re(I) atom has a distorted octa-hedral coordination environment. Two N atoms of the 5-phenyl-3-(pyridin-2-yl)-1H-1,2,4-triazole ligand and two of the three carbonyl groups occupy the equatorial plane of the complex, with the third carbonyl ligand and the bromide ligand in the axial positions. The three carbonyl ligands are arranged in a fac configuration around the Re(I) atom. Mutual N-H⋯Br hydrogen bonds arrange mol-ecules into centrosymmetric dimers. Additional stabilization within the crystal structure is provided by C-H⋯O and C-H⋯Br hydrogen bonds, as well as by slipped π-π stacking inter-actions [centroid-to-centroid distance = 3.785 (5) Å], defining a three-dimensional network.

The crystal structure of the title compound, strontium cadmium platinum, adopts the TiNiSi structure type with the Sr atoms on the Ti, the Cd atoms on the Ni and the Pt atoms on the Si positions, respectively. The Pt atoms form cadmium-centred tetra-hedra that are condensed into a three-dimensional network with channels parallel to the b-axis direction in which the Sr atoms are located. The latter are bonded to each other in the form of six-membered rings with chair conformations. All atoms in the SrCdPt structure are situated on a mirror plane.

In the title compound, the de-hydro-dipeptide (Boc-Phe-ΔAla-OiPr, C20H28N2O5), the mol-ecule has a trans conformation of the N-methyl-amide group. The geometry of the de-hydro-alanine moiety is to some extent different from those usually found in simple peptides, indicating conjugation between the H2C=C group and the peptide bond. The bond angles around de-hydro-alanine have unusually high values due to the steric hindrance, the same inter-action influencing the slight distortion from planarity of the de-hydro-alanine. The mol-ecule is stabilized by intra-molecular inter-actions between the isopropyl group and the N atoms of the peptide main chain. In the crystal, an N-H⋯O hydrogen bond links the mol-ecules into ribbons, giving a herringbone head-to-head packing arrangement extending along the [100] direction. In the stacks, the mol-ecules are linked by weak C-H⋯O hydrogen-bonding associations.

In the title compound, C27H21FN2O4, the mean planes of the two indole ring systems (r.m.s. deviations = 0.0166 and 0.0086 Å) are approximately perpendic-ular to one another, making a dihedral angle of 87.8 (5)°; the fluorobenzene ring is twisted with respect to the mean planes of the two indole ring systems at 82.7 (5) and 85.5 (3)°. In the crystal, pairs of N-H⋯O hydrogen bonds link the mol-ecules into the inversion dimers, which are further linked by N-H⋯O hydrogen bonds into supra-molecular chains propagating along the b-axis direction. Weak C-H⋯π inter-actions are observed between neighbouring chains.

The title compound, 2C9H9N3·HClO4, was prepared by reaction of 1-benzyl-1H-1,2,4-triazole and HClO4 in ethanol at room temperature. The asymmetric unit consists of two mol-ecules of 1-benzyl-1H-1,2,4-triazole and one of HClO4 mol-ecule. The benzene and triazole rings make dihedral angles of 85.45 (8) and 84.76 (8)° in the two mol-ecules. The H-atom position of the perchloric acid mol-ecule is split over two O atoms (real peaks on difference map), with site-occupation factors of 0.5. These H atoms form two classical hydrogen bonds [2.546 (5) and 2.620 (4) Å] with the same N atoms in both mol-ecules. Five inter-molecular non-classical C-H⋯O inter-actions, with C⋯O distances in the range 3.147 (5)-3.483 (5) Å, are found in the crystal structure.