Zeynep Demircioğlu

Experimental (X-ray, FT-IR and UV-vis spectra) and theoretical methods (DFT study) of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol.

A suitable single crystal of (E)-3-methoxy-2-[(p-tolylimino)methyl]phenol, formulated as C15H15N1O2, reveals that the structure is adopted to its E configuration about the azomethine C=N double bond. The compound adopts a enol-imine tautomeric form with a strong intramolecular O-H⋯N hydrogen bond. The single crystal X-ray diffraction analysis at 296K crystallizes in the monoclinic space group P21/c with a = 13.4791(11) Å, b = 6.8251(3) Å, c = 18.3561(15) Å, α = 90°, β = 129.296(5)°, γ = 90° and Z = 4. Comprehensive theoretical and experimental structural studies on the molecule have been carried out by FT-IR and UV-vis spectrometry. Optimized molecular structure and harmonic vibrational frequencies have been investigated by DFT/B3LYP method with 6-31G(d,p) basis set. Stability of the molecule, hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed by using natural bond orbital (NBO) analysis. Electronic structures were discussed by TD-DFT method and the relocation of the electron density were determined. The energetic behavior of the title compound has been examined in solvent media using polarizable continuum model (PCM). Molecular electrostatic potential (MEP), Mulliken population method and natural population analysis (NPA) have been studied. Nonlinear optical (NLO) properties were also investigated. In addition, frontier molecular orbitals analysis have been performed from the optimized geometry. An ionization potential (I), electron affinity (A), electrophilicity index (ω), chemical potential (μ), electronegativity (χ), hardness (η), and softness (S), have been investigated.

The spectroscopic (FT-IR, UV–vis), Fukui function, NLO, NBO, NPA and tautomerism effect analysis of (E)-2-[(2-hydroxy-6-methoxybenzylidene)amino]benzonitrile

A new o-hydroxy Schiff base, (E)-2-[(2-hydroxy-6-methoxybenzylidene)amino]benzonitrile was isolated and investigated by experimental and theoretical methodologies. The solid state molecular structure was determined by X-ray diffraction method. The vibrational spectral analysis was carried out by using FT-IR spectroscopy in the range of 4000-400cm(-)(1). Theoretical calculations were performed by density functional theory (DFT) method using 6-31G(d,p) basis set. The results of the calculations were applied to simulated spectra of the title compound, which show excellent agreement with observed spectra. The UV-vis spectrum of the compound was recorded in the region 200-800 nm in several solvents and electronic properties such as excitation energies, and wavelengths were calculated by TD-DFT/B3LYP method. The most prominent transitions were corresponds to π→π∗. Hybrid density functional theory (DFT) was used to investigate the enol-imine and keto-amine tautomers of titled compound. The titled compound showed the preference of enol form, as supported by X-ray and spectroscopic analysis results. The geometric and molecular properties were compaired for both enol-imine and keto-amine forms. Additionally, geometry optimizations in solvent media were performed with the same level of theory by the integral equation formalism polarizable continuum (IEF-PCM). Stability of the molecule arises from hyperconjugative interactions, charge delocalization and intramolecular hydrogen bond has been analyzed using natural bond orbital (NBO) analysis. Mulliken population method and natural population analysis (NPA) have been studied. Also, condensed Fukui function and relative nucleophilicity indices calculated from charges obtained with orbital charge calculation methods (NPA). Molecular electrostatic potential (MEP) and non linear optical (NLO) properties are also examined.

X-ray structural, spectroscopic and computational approach (NBO, MEP, NLO, NPA, fukui function analyses) of (E)-2-((4-bromophenylimino)methyl)-3-methoxyphenol

ABSTRACT The title compound was isolated and investigated by experimental X-ray diffraction method and density functional theory (DFT) calculational properties and spectroscopic methodologies. The experimental investigations of the compound indicated the molecule seems to be in enol form. DFT calculations are performed both for enol and keto tautomers of the title compound. Additionally chemical activity, electronic transmission and property effect on different solvents, molecular electrostatic potential (MEP), non-linear optical properties (NLO), Mulliken population method, natural population analysis (NPA), natural bond orbital (NBO) and Fukui function analyses have been studied.

Synthesis, X-Ray Structural, Characterization, NLO, MEP, NBO, and HOMO–LUMO Analysis Using DFT Study of Co(II)bis(3,4 dimethoxybenzoate)bis(nicotinamide) Dihydrate

A suitable single crystal of Co(II)bis(3,4 dimethoxybenzoate)bis(nicotinamide) dihydrate, formulated as C30H38N4O14Co,(I). According to experimental data, the complex can be characterized in the solid state as mononuclear, with a distorted octahedral stereochemistry. The distorted octahedral stereochemistry adopted by the complex was further confirmed by the x-ray structure analysis of current study, which consists of a six-coordinate Co atom in a distorted octahedral environment constructed from two N atoms and four O atoms. The title compound which has been characterized by IR, UV, and single crystal X-ray diffraction analysis at 296 K crystallizes in the monoclinic space group C 2/c with a = 27.9402(15) Å, b = 8.6005(3)Å, c = 14.7921(9)Å, α = 90°, β = 108.849(4)°, and γ = 90°, Z = 4. The molecular structure and geometry have also been optimized using B3LYP density functional theory method employing the 6-31G (d) basis set. The molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis, nonlinear optical properties (NLO), and natural bond analysis (NBO) for the title molecule are also described from the computational process.

Synthesis, spectroscopic characterization, X-ray structure and DFT calculations of Ni(II)bis(3,4 dimethoxybenzoate)bis(nicotinamide) dihydrate

Abstract A single crystal of Ni(II)bis(3,4 dimethoxybenzoate)bis(nicotinamide) dihydrate, formulated as C30H34N4NiO12 (I), was characterized in the solid state by infra-red (IR), ultra-violet (UV) and single crystal X-ray diffraction analysis at 296 K as mononuclear with a distorted octahedral stereochemistry. The complex consists of a six-coordinate Nickel atom in a distorted octahedral environment constructed from two N atoms and four O atoms and crystallizes in the monoclinic space group C 2/c with a=27.7680(16) Å, b=8.5748(3) Å, c=17.8018(9) Å, α=90°, β=108.154(4)°, γ=90°, Z=4. The molecular structure and geometry was also optimized using the B3LYP density functional theory method employing the 6-31G(d) basis set. The molecular electrostatic potential (MEP), frontier molecular orbitals (FMO) analysis, nonlinear optical properties (NLO) and natural bond analysis (NBO), Mulliken population analyis, natural population analysis (NPA) and Fukui function analysis were also described.

Crystal structure of 2-(aza­niumylmeth­yl)pyridinium bis(hydrogen squarate)

The structure of the title squarate salt is reported. Classical N—H⋯O and O—H⋯O hydrogen bonds combine with weak C—O⋯π(ring) and π–π contacts to stabilize the crystal packing.

Crystal structure of (Z)-4-[1-(4-acetyl­anilino)ethyl­idene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

In the solid state, the title compound, adopts the keto–amine tautomeric form, with the H atom attached to the N atom, which participates in an intramolecular N—H⋯O hydrogen bond with an S(6) ring motif. In the crystal, molecules are linked by weak C—H⋯O hydrogen bonds to generate C(16) chains propagating in the [301] direction.

Synthesis, X-ray structural characterization, NLO, MEP, NBO and HOMO-LUMO analysis using DFT study of Zn(II)bis(3,4 dimethoxybenzoate)bis(nicotinamide) dihydrate

Abstract A single crystal of Zn(II)bis(3,4 dimethoxybenzoate)bis(nicotinamide) dihydrate, formulated as C30H38N4O14Zn, (I) has been obtained. According to experimental data, the complex can be characterized in the solid state as mononuclear, with a distorted octahedral stereochemistry. The distorted octahedral stereochemistry adopted by the complex was further confirmed by X-ray structure analysis of the current study, which consists of a six-coordinate Zn atom in a distorted octahedral environment constructed from two N atoms and four O atoms. The title compound crystallizes in the monoclinic space group C 2/c with a = 27.9248(18) Å, b = 8.5941(4) Å, c = 14.8344(11) Å, α = 90°, β = 108.651(5)°, γ = 90°, Z = 4. The molecular structure and geometry were also optimized using the B3LYP density functional theory method employing the 6-31G (d) basis set. Molecular electrostatic potential, frontier molecular orbital analysis, nonlinear optical properties and natural bond analysis for the title molecule are also described from the computational process.