Cyclo­hexane plastic phase I: single-crystal diffraction images and new structural model

Diffraction images for the plastic phase I of cyclo­hexane at 255 K show that molecules are disordered over 24 positions, through four-, three- and twofold rotation axis in space group Fm3m, forming clusters in which the C atoms are located on the vertices of a rhombic dodecahedron.

Bis[2-(thio­phen-2-yl)quinoxaline-κN⁴]silver(I) perchlorate

The structure of bis­[2-(thio­phen-2-yl)quinoxaline-κN⁴]silver(I) perchlorate, [Ag(C₁₂H₈N₂S)₂]ClO₄, has a silver(I) metal center that sits on a twofold symmetry axis, as does a disordered perchlorate anion. The thienylquinoxaline ligand is nearly planar with the thienyl ring making a dihedral angle of 10.88 (8)° with respect to the quinoxaline moiety.

Bis[5-methyl-2,3-bis­(thio­phen-2-yl)quinoxaline-κN¹](nitrato-κ²O,O′)silver(I)

In the title compound, the silver(I) metal center sits on a twofold rotation axis, as does the coordinated nitrato anion. The two 2-thienyl groups of the ligand make dihedral angles of 17.14 (9) and 77.55 (6)° with respect to the quinoxaline plane. The thienyl group that is less planar with the quinoxaline ring exhibits ring-flip disorder.

3-Methyl-2-(methyl­sulfan­yl)-5,5-di­phenyl-3,5-di­hydro-4H-imidazol-4-one

In the title mol­ecule, C₁₇H₁₆N₂OS, the di­hydro­imidazolone ring is slightly puckered and the methyl­sulfanyl group is nearly coplanar with it.

Meloxicam hydro­chloride

The crystal structure determined for meloxicam hydro­chloride is not isomorphous with the known structure of the hydro­bromide analogue.

N-(4-Meth­oxy-2-nitro­phenyl)-2-(3-methyl-2-oxo-1,2-di­hydroquinoxalin-1-yl)acetamide

The quinoxaline unit in the title mol­ecule is slightly puckered [dihedral angle between the rings = 2.07 (12)°] while the whole mol­ecule adopts an L-shaped conformation. The packing in the crystal is governed by C—H⋯O hydrogen bonds and slipped π-stacking inter­actions.

(1S,2S)-2-[(S)-2,2,2-Tri­fluoro-1-hy­droxy­eth­yl]-1-tetra­lol

The title enanti­opure tetra­lol derivative synthesized by asymmetric transfer hydrogenation crystallizes in the Sohncke space group P2₁2₁2₁ and features one mol­ecule in the asymmetric unit. In the crystal, mol­ecules are hydrogen-bonded into chains running parallel to [010].

rac-N-(4-Eth­oxy­phen­yl)-3-hy­droxy­butanamide

The crystal structure of bucetin, an analgesic and anti­pyric similar to phenacetin, is presented.