Başak Koşar

2-Hydr­oxy-6-[(2-hydroxy­phenyl­amino)methyl­ene]cyclo­hexa­-2,4-dienone

The title compound, C13H11NO3, adopts the keto–amine tautomeric form, with the H atom located on N rather than on O. This H atom is involved in a strong intraxadmolecular hydrogen bond. There are two independent molecules in the asymmetric unit. The molxadecules are linked by intraxadmolecular N—H⋯O and O—H⋯O and interxadmolecular O—H⋯O hydrogen bonds into a three-dimensional network.

(E)-2-((4-Chlorophenyl)iminomethyl)-5-methoxyphenol and (E)-2-((2-chlorophenyl)iminomethyl)-5-methoxyphenol: X-ray and DFT-calculated structures

The crystal structures of the title 4-chlorophenyl, (I), and 2-chlorophenyl, (II), compounds, both C14H12ClNO2, have been determined using X-ray diffraction techniques and the molecular structures have also been optimized at the B3LYP/6-31 G(d,p) level using density functional theory (DFT). The X-ray study shows that the title compounds both have strong intramolecular O-H...N hydrogen bonds and that the crystal networks are primarily determined by weak C-H...pi and van der Waals interactions. The strong intramolecular O-H...N hydrogen bond is evidence of the preference for the phenol-imine tautomeric form in the solid state. The IR spectra of the compounds were recorded experimentally and also calculated for comparison. The results from both the experiment and theoretical calculations are compared in this study.

(E)-2-Methyl-4-[(4-nitrophenyl)diazenyl]phenol dimethylformamide solvate

The title compound, C13H11N3O3·C3H7NO, displays an interxadmolecular O—H⋯O hydrogen bond between the hydroxyl group and the carbonyl O atom of the solvent molxadecule. The configuration of the N=N double bond is trans and the dihedral angle between the two aromatic rings is 24.85u2005(6)°.

tert-Butyl N-(2-bromo­cyclo­hex-2-enyl)-N-(2-furylmethyl)carbamate

In the title compound, C16H22BrNO3, the molxadecules are linked only by weak van der Waals interxadactions. The bromo attached cyclohexane ring adopts a half-chair conformation.

6-Bromo-8-thia-1,4-epoxy­bicyclo­[4.3.0]non-2-ene

In the title compound, C8H9BrOS, the molxadecules are linked only by weak van der Waals interxadactions.

4-[(3-Chloro­phenyl)­diazenyl]-6-methoxy-2-{[tris­(hydroxy­methyl)­methyl]­aminomethyl­ene}cyclo­hexa-3,5-dien-1(2H)-one

Department of Physics, Faculty of Arts and Sciences, Ondokuz Mayõs University, 55139 Kurupelit Samsun, Turkey, Department of Chemistry, Faculty of Arts and Sciences, Ondokuz Mayõs University, 55139 Kurupelit Samsun, Turkey, and Institut fuÈ r Anorganische und Analytische Chemie, Technische UniversitaÈt Braunschweig, Postfach 3329, 38023 Braunschweig, Germany Correspondence e-mail: ccersan@omu.edu.tr

3a-Bromoperhydro-2,6a-epoxyoxireno[e][2]benzofuran

In the title compound, C8H9BrO3, the boat form of the six-membered ring is almost symmetrical with respect to the epxadoxy bridge. The two five-membered rings generated by the epxadoxy bridge of the six-membered ring adopt envelope conformations, whereas the third five-membered ring adopts a half-chair conformation. The refinement results suggest partial inversion twinning.

6-Chloro-8-thia-1,4-epoxy­bicyclo­[4.3.0]non-2-ene

In the structure of the title compound, C8H9ClOS, the six-membered ring has a boat conformation and the S-containing five-membered ring has an envelope conformation. The molxadecules are linked only by weak van der Waals interxadactions.

4-[(4-Methyl­phenyl)­diazenyl]-6-methoxy-2-{[tris­(hydroxy­methyl)­methyl]­amino­methyl­ene}cyclo­hexa-3,5-dien-1(2H)-one

The title compound, C18H20ClN3O5, adopts the keto–amine tautomeric form and displays an intramolecular N—H⋯O hydrogen bond. The configuration around the azo N=N double bond is trans and the dihedral angle between the two aromatic rings is 10.0u2005(1)°. Intermolecular O—H⋯O hydrogen bonds form a three-dimensional network.

4‐(2,6‐Di­methyl­phenoxy)­phthalo­nitrile

In the title compound, C16H12N2O, two benzene rings are linked by an O atom. One of the benzene rings carries two cyano groups. The compound crystallizes with two independent molxadecules in the asymmetric unit. The crystal structure is stabilized by weak van der Waals interactions.