Serap Yazıcı

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].

1-{5-[(E)-(2-Fluoro-phen-yl)diazen-yl]-2-hy-droxy-phen-yl}ethanone.

Theere are two independent molecules in the asymmetric unit of the title compound, C14H11FN2O2, each with a trans configuration with respect to the azo double bond. The dihedral angle between the aromatic rings is 17.21 (2)° in one molecule and 19.06 (2)° in the other. Each of the independent molecules has an intramolecular O—H⋯O hydrogen bond. In the crystal, molecules are stacked along [100].

(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.

4-{2-Meth-oxy-6-[(4-methyl-phen-yl)imino-meth-yl]phen-oxy}phthalonitrile.

In the molecule of the title compound, C23H17N3O2, the methoxyphenyl ring is oriented at dihedral angles of 13.34 (12) and 88.83 (12)° with respect to the methylphenyl and phthalonitrile rings, respectively; the dihedral angle between methylphenyl and phthalonitrile rings is 89.67 (10)°. In the crystal structure, weak intermolecular C—H⋯N interactions link molecules into chains. A weak C—H⋯π interaction is also found..

Crystal structure and DFT calculations of two derivatives of phthalimide

25th European Crystallographic Meeting, ECM 25, İstanbul, 2009 Acta Cryst. (2009). A65, s 266 Page s 266 structure for the same molecule, has been suggested as “an anathema to crystal engineering” [1], and the same might well be said about crystal structure prediction. Polymorphism is of special importance in pharmaceutical industry processes, where different physical properties of polymorphic forms can substantially alter the viability and quality of a product such as drug [2]. Comparisons of the intermolecular interactions in polymorphic structures are very important for elucidating their properties. Hirshfeld surface is becoming a valuable tool for analyzing intermolecular interactions while maintaining whole-of-The size and shape of a Hirshfeld surface reflects the interplay between different atoms and intermolecular contacts in a crystal, and hence the surface necessarily reflect different intermolecular interactions.molecule approach [3]. In this study, we report the crystal structure and Hirshfeld surface analysis of two polymorphs of a potentially bidentate diimine ligand.