İsmet Şenel

Experimental and quantum chemical computational study of (E)-1-[5-(3,4-dimethylphenyldiazenyl)-2-hydroxyphenyl]ethanone

In this work, the azo dye, (E)-1-[5-(3,4-dimethylphenyldiazenyl)-2-hydroxyphenyl]ethanone, has been synthesized and characterized by IR, and X-ray single-crystal determination. In the theoretical calculations, the stable structure geometry of the isolated molecule in gas phase was investigated under the framework of the density functional theory (B3LYP) with 6-31G (d, p). To designate lowest energy molecular conformation of the title molecule, the selected torsion angle was varied every 10° and the molecular energy profile was calculated from -180° to +180°. Besides, molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis, and thermodynamic properties were described from the computational process. In addition to these calculations, we were investigated solvent effects on the nonlinear optical properties (NLO) of the title compound.

(E)-2-Acetyl-4-[(3-methyl-phenyl-)diazen-yl]phenol: an X-ray and DFT study.

The title compound, C15H14N2O2, an azo dye, displays a trans configuration with respect to the N=N bridge. The dihedral angle between the aromatic rings is 0.18 (14)°. There is a strong intramolecular O—H⋯O hydrogen bond. Geometrical parameters, determined using X-ray diffraction techniques, are compared with those calculated by density functional theory (DFT), using hybrid exchange–correlation functional, B3LYP and semi-empirical (PM3) methods.

1-{5-[(E)-(4-Propyl­phen­yl)diazen­yl]-2-hy­droxy­phen­yl}ethanone

The molecular geometry of the title compound, C17H18N2O2, displays an E configuration with respect to the azo group. The dihedral angle between the aromatic rings is 10.39 (4)°. In the molecule, an intramolecular O—H⋯O hydrogen bond generates an S(6) ring motif.

(E)-2-Hydr-oxy-6-[(4-propyl-phenyl)-iminiometh-yl]phenolate.

The title compound, C16H17NO2, crystallizes with three crystallographically independent zwitterionic molecules in the asymmetric unit which differ significantly in the orientations of the propyl side chains. The dihedral angles between the two benzene rings in the three molecules are 6.17 (7), 6.75 (7) and 23.67 (7)°, respectively. In each independent molecule, an intramolecular N—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, each independent molecule exists as part of an O—H⋯O hydrogen-bonded centrosymmetric R 2 2(10) dimer.

(E)-2-[(2-Ethyl-phen-yl)iminiometh-yl]-6-hydroxy-phenolate.

The molecule of the title compound, C15H15NO2, crystallizes in a zwitterionic form, and displays an E configuration about the C=N bond. The dihedral angle between the two aromatic rings is 5.59 (6)°. An intramolecular N—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal structure, pairs of molecules are linked into centrosymmetric R 2 2(10) dimers by pairs of O—H⋯O hydrogen bonds. Aromatic π–π interactions are observed between the benzene rings of adjacent dimers [centroid–centroid distance = 3.4808 (7) Å].

(E)-2-Methyl-6-[3-(trifluoromethyl)phenyliminomethyl]phenol

The title compound, C15H12F3NO2, adopts the phenol–imine tautomeric form, with the H atom attached to oxygen rather than to nitrogen. There are two independent molecules aligned nearly parallel in the asymmetric unit with their trifloramethyl groups pointing in opposite directions. The dihedral angles between the aromatic rings are 40.43 (1) in the first molecule and 36.12 (1) in the second. Strong intramolecular O—H N hydrogen bonding generates S(6) ring motifs. Weak intermolecular C—H O hydrogen bonds link the independent molecules separately into sheets normal to [010]. In addition, C—H interactions are also observed. The F atoms of the trifluoromethyl groups are disordered over two sets of sites with refined site occupancies of 0.59 (2)/ 0.41 (2) and 0.62 (3)/0.38 (3), respectively.

4,4′-(4,4′-Thio­di­phenoxy)­diphthalo­nitrile

The title compound, C28H14N4O2S, contains four aromatic rings, and the crystal structure is stabilized by π–π stacking.

4-Di­phenyl­methoxy­phthalo­nitrile

The title compound, C21H14N2O, contains three aromatic rings. The structure is stabilized by π–π stacking interactions.

(E)-2-[(2-Ethyl-phen-yl)imino-meth-yl]-6-methoxy-phenol.

The molecule of the title compound, C16H17NO2, adopts the phenol–imine tautomeric form with a strong intramolecular O—H⋯N hydrogen bond and an E conformation with respect to the azomethine C=N bond. The dihedral angle between the aromatic rings is 21.23 (9)°. The ethyl group is disordered over two orientations with occupancies of 0.598 (6) and 0.402 (6). In the crystal, the molecules are linked into chains along the b axis by C—H⋯π interactions.

2-[(4-Chloro­phen­yl)imino­meth­yl]hydro­quinone

The title compound, C13H10ClNO2, exists in the phenol–imine form in the crystal, and the aromatic rings are oriented at a dihedral angle of 2.82 (9)°. An intramolecular O—H⋯N hydrogen bond results in the formation of a planar six-membered ring. In the crystal structure, intermolecular O—H⋯O hydrogen bonds link the molecules into chains.