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Molecular structure, spectroscopic investigations, second-order nonlinear optical properties and intramolecular proton transfer of (E)-5-(diethylamino)-2-[(4-propylphenylimino)methyl]phenol: A combined experimental and theoretical study

This work presents a combined experimental and theoretical study on an ortho-hydroxy Schiff base compound, (E)-5-(diethylamino)-2-[(4-propylphenylimino)methyl]phenol. The crystal structure and spectroscopic properties of the compound have been determined by using X-ray diffraction, IR and UV-vis spectroscopy techniques. The electronic structure, vibrational frequencies and electronic absorption spectra have been investigated from the calculative point of view. A relaxed potential energy surface scan has been performed based on the optimized geometry of OH tautomeric form to describe the potential energy barrier belonging to intramolecular proton transfer and to observe the effects of transfer on the molecular geometry. The second-order nonlinear optical properties have been investigated based on the first static hyperpolarizability (β) by using the density functional theory.

2-[(2-hydroxy-4-nitrophenyl)aminomethylene]cyclohexa-3,5-dien-1(2H)-one.

The title compound, C(13)H(10)N(2)O(4), adopts the keto-amine tautomeric form and displays an intramolecular N-H...O [N...O = 2.579 (2) A] and three intermolecular O-H...O [O...O = 2.561 (2) A] and C-H...O [C...O = 3.274 (2) and 3.318 (2) A] hydrogen bonds. The keto-amine structure is favoured by through-molecule conjugation between the hydroxy O atom and imine N atom. The dihedral angle between the planes of the two aromatic rings is 10.79 (4) degrees.

The crystal structures of three 3-methyl-1H-1,2,4-triazole-5-thio­nes, including a second polymorph of 4-[(E)-(5-bromo-2-hy­droxy­benzyl­idene)amino]-3-methyl-1H-1,2,4-triazole-5(4H)-thione and a redetermination of 4-amino-3-methyl-1H-1,2,4-triazole-5(4H)-thione

The non-H atoms in the molecules of three closely-related 4-amino-3-methyl-1H-1,2,4-triazole-5-thiones are either exactly or very nearly co-planar, and the compounds exhibit hydrogen-bonded supramolecular assembly in two, one or zero dimensions.

(2-Hydroxyethyl)hydrazinium(2+) dichloride.

The crystal structure of the title compound, C2H10N2O(2+).2Cl-, is built up from one 2-hydroxyethylhydrazinium(2+) cation and two Cl- anions. The molecular structure is stabilized by O-H...Cl and N-H...Cl hydrogen bonds. The crystal structure is stabilized by one N-H...O and three N-H...Cl interactions, and the three-dimensional network of hydrogen bonds stabilizes the crystal packing. All five hydrazinium H atoms are involved in hydrogen bonds to Cl- anions. The Cl...H contact distances range from 2.122 (15) to 2.809 (14) A.

trans,trans,trans‐2,3,5,8‐Tetra­bromo‐1,4‐di­hydroxy‐1,2,3,4‐tetra­hydro­naphthalene

The structure of the title compound, C10H8Br4O2, has been determined at room temperature. The ten-membered tetrahydronaphthalene ring system is nearly planar, with a total puckering amplitude QT of 0.386 (5) A. The crystal structure is stabilized by short inter- and intramolecular hydrogen-bond contacts.

Crystal structure of 3,4a,7,7,10a-penta-methyl-3-vinyl-dodeca-hydro-1H-benzo[f]chromen-9-ol isolated from Sideritis perfoliata.

In the two independent molecules in the asymmetric unit of the title compound, the cyclohexane rings adopt a chair conformation, while the oxane rings are also puckered. In the crystal, O—H⋯ O hydrogen bonds connect adjacent molecules, forming a C(6) helical chain running along the [100] direction.

Dihydrooxazolones and dihydroimidazolones derived from acylglycines: syntheses, molecular structures and supramolecular assembly.

Syntheses and structures are described for some alkylidene-substituted dihydrooxazolones and dihydroimidazoles derived from simple acylglycines. A second, triclinic, polymorph of 4-benzylidene-2-(4-methylphenyl)-1,3-oxazol-5(4H)-one, C17H13NO2, (I), has been identified and the structure of 2-methyl-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one, C9H7NO2S, (II), has been rerefined taking into account the orientational disorder of the thienyl group in each of the two independent molecules. The reactions of phenylhydrazine with 2-phenyl-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one or 2-(4-methylphenyl)-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one yield, respectively, 3-anilino-2-phenyl-5-[(thiophen-2-yl)methylidene]-3,5-dihydro-4H-imidazol-4-one, C10H15N3OS, (III), and 3-anilino-2-(4-methylphenyl)-5-[(thiophen-2-yl)methylidene]-3,5-dihydro-4H-imidazol-4-one, C21H17N3OS, (IV), which both exhibit orientational disorder in their thienyl groups. The reactions of 2-phenyl-4-[(thiophen-2-yl)methylidene]-1,3-oxazol-5(4H)-one with hydrazine hydrate or with water yield, respectively, N-[3-hydrazinyl-3-oxo-1-(thiophen-2-yl)prop-1-en-2-yl]benzamide and 2-(benzoylamino)-3-(thiophen-2-yl)prop-2-enoic acid, which in turn react, respectively, with thiophene-2-carbaldehyde to form 2-phenyl-5-[(thiophen-2-yl)methylidene]-3-{[(E)-(thiophen-2-yl)methylidene]amino}-3,5-dihydro-4H-imidazol-4-one, C19H13N3OS2, (V), which exhibits orientational disorder in only one of its thienyl groups, and with methanol to give methyl (2Z)-2-(benzoylamino)-3-(thiophen-2-yl)prop-2-enoate, C15H13NO3S, (VI). There are no direction-specific intermolecular interactions in the crystal structure of the triclinic polymorph of (I), but the molecules of (II) are linked by two independent C-H···O hydrogen bonds to form C2(2)(14) chains. Compounds (III) and (IV) both form centrosymmetric R2(2)(10) dimers built from N-H···O hydrogen bonds, while compound (V) forms a centrosymmetric R2(2)(10) dimer built from C-H···O hydrogen bonds. In the structure of compound (VI), a combination of N-H···O and C-H···π(arene) hydrogen bonds links the molecules into sheets. Comparisons are made with some similar compounds.

3-Methoxy-5-(4-methyl­phenyl­diazenyl)­salicyl­aldehyde and 3-methoxy-5-(2-methyl­phenyl­diazenyl)­salicyl­aldehyde

The two title molecules, both C 15 H 14 N 2 O 3 , are roughly planar and display a trans conformation with respect to the -N=N-double bond, as found for other diazene derivatives. In both compounds, there are intramolecular O-H...O hydrogen bonds and the crystal packing is governed by weak intermolecular C-H...O hydrogen bonds and π-π stacking.

Density functional theory study of a silver N-heterocyclic carbene complex

Geometry optimization was carried out by using the density functional theory method with B3LYP applying 6-31G* basis set by plotting the X-ray single crystal structure in the gas phase. Some solven...

Crystal structure of racemic [(1R,2S,3R,4S,6S)-2,6-bis­(furan-2-yl)-4-hy­droxy-4-(thio­phen-2-yl)cyclo­hexane-1,3-di­yl]bis­(thio­phen-2-yl­methanone)

The central cyclohexane ring has a chair conformation. In the crystal, molecules are linked by C—H⋯O hydrogen bonds and C—H⋯π interactions, forming layers parallel to (100).