Preparation, spectroscopic, X-ray crystallographic, DFT, antimicrobial and ADMET studies of N-[(4-flourophenyl)sulfanyl]phthalimide.

N-[(4-Fluorophenyl)sulfanyl]phthalimide (C14H8FNO2S, FP) was synthesized and characterized using X-ray crystallography. It was then investigated via quantum chemical analysis using the density functional theory (DFT) approach, as well as spectrochemically using FT-IR and 1H and 13C NMR spectroscopy, and elemental analysis. The observed and stimulated spectra are in very good agreement for the DFT method. The in vitro antimicrobial activity of FP against three Gram-positive bacteria, three Gram-negative bacteria and two fungi were determined using the serial dilution method, and FP showed the highest antibacterial activity against E. coli, with a MIC of 128 µg ml-1. Druglikeness, ADME (absorption, distribution, metabolism and excretion) and toxicology studies were carried out to theoretically examine the drug properties of FP.

Crystal structure and DFT computational studies of (E)-2,4-di-tert-butyl-6-{[3-(tri-fluoro-meth-yl)benz-yl]imino-meth-yl}phenol.

The title compound, C23H28F3NO, is an ortho-hy-droxy Schiff base compound, which adopts the enol-imine tautomeric form in the solid state. The mol-ecular structure is not planar and the dihedral angle between the planes of the aromatic rings is 85.52 (10)°. The tri-fluoro-methyl group shows rotational disorder over two sites, with occupancies of 0.798 (6) and 0.202 (6). An intra-molecular O-H⋯N hydrogen bonding generates an S(6) ring motif. The crystal structure is consolidated by C-H⋯π inter-actions. The mol-ecular structure was optimized via density functional theory (DFT) methods with the B3LYP functional and LanL2DZ basis set. The theoretical structure is in good agreement with the experimental data. The frontier orbitals and mol-ecular electrostatic potential map were also examined by DFT computations.

Molecular structure and vibrational and chemical shift assignments of 3'-chloro-4-dimethylamino azobenzene by DFT calculations.

In the present work, a combined experimental and theoretical study on ground state molecular structure, spectroscopic and nonlinear optical properties of azo compound 3'-chloro-4-dimethlamino azobenzene are reported. The molecular geometry, vibrational wavenumbers and the first order hyperpolarizability of the title compound were calculated with the help of density functional theory computations. The optimized geometric parameters obtained by using DFT (B3LYP/6-311++G(d,p)) show good agreement with the experimental data. The vibrational transitions were identified based on the recorded FT-IR spectra in the range of 4000-400cm(-1) for solid state. The (1)H isotropic chemical shifts with respect to TMS were also calculated using the gauge independent atomic orbital (GIAO) method and compared with the experimental data. Using the TD-DFT method, electronic absorption spectra of the title compound have been predicted, and good agreement is determined with the experimental ones. To investigate the NLO properties of the title compound, the polarizability and the first hyperpolarizability were calculated using the density functional B3LYP method with the 6-311++G(d,p) basis set. According to results, the title compound exhibits non-zero first hyperpolarizability value revealing second order NLO behavior. In addition, DFT calculations of the title compound, molecular electrostatic potential and frontier molecular orbitals were also performed at 6-311++G(d,p) level of theory.

Molecular structure and vibrational assignment of 1-[N-(2-pyridyl) aminomethylidene}-2(1H)-Naphtalenone by density functional theory (DFT) and ab initio Hartree-Fock (HF) calculations.

The molecular geometry and vibrational frequencies of 1-[N-(2-pyridyl)aminomethylidene}-2(1H)-Naphtalenone in the ground state have been calculated by using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-311++G(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The computed vibrational frequencies were used to determine the types of molecular motions associated with each of the experimental bands observed. In addition, calculated results are related to the linear correlation plot of computed data versus experimental geometric parameters and IR data. From the results it was concluded that the B3LYP method is superior to the HF method for the vibrational frequencies. Using the time-dependent density functional theory (TD-DFT) and Hartree-Fock (TD-HF) methods, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and experimental ones is determined.

Crystal structure of 2-{[(5-nitro-thio-phen-2-yl)methyl-idene]amino}-phenol.

The title compound, C11H8N2O3S, is roughly planar; the di-hedral angle between the planes of the thio-phene and benzene rings is 8.38 (10)°. An intra-molecular O-H⋯N hydrogen bond generates an S(5) ring motif. In the crystal, mol-ecules are linked into centrosymmetric dimers by pairs of O-H⋯O hydrogen bonds with an R 2 (2)(22) graph-set motif. Aromatic π-π stacking inter-actions [centroid-centroid sep-ar-ations = 3.653 (3) and 3.852 (3) Å] link the dimers into a three-dimensional network.

Experimental (XRD, FT-IR and UV-Vis) and theoretical modeling studies of Schiff base (E)-N'-((5-nitrothiophen-2-yl)methylene)-2-phenoxyaniline.

The Schiff base compound (E)-N'-((5-nitrothiophen-2-yl)methylene)-2-phenoxyaniline has been synthesized and characterized by IR, UV-Vis, and X-ray diffraction (XRD) methods. The molecular geometry from X-ray experiment in the ground state has been compared using the density functional theory (DFT) with the 6-311++G(d,p) basis set. The calculated results show that the optimized geometry can well reproduce the crystal structure, and the theoretical vibrational frequency values show good agreement with experimental values. By using TD-DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental one is determined. The energetic behavior of the title compound in solvent media has been examined using B3LYP method with the 6-311++G(d,p) basis set by applying the Onsager and the integral equation formalism polarizable continuum model (IEF-PCM). The predicted nonlinear optical properties of the title compound are greater than ones of urea. In addition, DFT calculations of the title compound, molecular electrostatic potential (MEP), natural bond orbital (NBO) and thermodynamic properties were performed at B3LYP/6-311++G(d,p) level of theory.

2-{(E)-[(2-Methyl-3-nitro-phen-yl)imino]-meth-yl}-4-nitro-phenol.

The title compound, C14H11N3O5, is a Schiff base that adopts the enol-imine tautomeric form in the solid state. The dihedral angle between the aromatic rings is 37.4 (3)° and the dihedral angles between the nitro groups and their attached rings are 4.0 (6) and 46.2 (8)°. The mol-ecular structure is stabilized by an intra-molecular O-H⋯N hydrogen bond, which generates an S(6) ring motif. In the crystal, molecules are linked by C-H⋯O interactions, forming a two-dimensional network parallel to the bc plane.

Molecular structure, vibrational spectra, NLO and MEP analysis of bis[2-hydroxy-кO-N-(2-pyridyl)-1-naphthaldiminato-кN]zinc(II).

The molecular geometry and vibrational frequencies of bis[2-hydroxy-кO-N-(2-pyridyl)-1-naphthaldiminato-кN]zinc(II) in the ground state have been calculated by using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-311G(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The energetic and atomic charge behavior of the title compound in solvent media has been examined by applying the Onsager and the polarizable continuum model. To investigate second order nonlinear optical properties of the title compound, the electric dipole (µ), linear polarizability (α) and first-order hyperpolarizability (ß) were computed using the density functional B3LYP and CAM-B3LYP methods with the 6-31+G(d) basis set. According to our calculations, the title compound exhibits nonzero (ß) value revealing second order NLO behavior. In addition, DFT calculations of the title compound, molecular electrostatic potential (MEP), frontier molecular orbitals, and thermodynamic properties were performed at B3LYP/6-311G(d,p) level of theory.

Synthesis, structural characterization and comparison of experimental and theoretical results by DFT level of molecular structure of 4-(4-methoxyphenethyl)-3,5-dimethyl-4H-1,2,4-triazole.

4-(4-Methoxyphenethyl)-3,5-dimethyl-4H-1,2,4-triazole (3) was synthesized from the reaction of ethyl N'-acetylacetohydrazonate (1) with 2-(4-methoxyphenyl)ethanamine (2). The structure of the title compound 3 has been inferred through IR, (1)H/(13)C NMR, mass spectrometry, elemental analyses and combination of X-ray crystallography and theoretical methods. In addition to the molecular geometry from X-ray determination, the molecular geometry and vibrational frequencies of the title compound 3 in the ground state, were calculated using the density functional method (B3LYP) with the 6-31G(d) basis set. The calculated results show that the optimized geometry can well reproduce the crystal structure and the theoretical vibrational frequencies show good agreement with experimental values. The nonlinear optical properties are also addressed theoretically. The predicted nonlinear optical properties of 3 are greater than ones of urea. In addition, DFT calculations of molecular electrostatic potentials and frontier molecular orbitals of the title compound were carried out at the B3LYP/6-31G(d) level of theory.

Molecular structure and vibrational spectra of Bis(melaminium) terephthalate dihydrate: a DFT computational study.

The experimental and theoretical vibrational spectra of Bis(melaminium) terephthalate dihydrate were studied. The Fourier transform infrared (FT-IR) spectra of the Bis(melaminium) terephthalate dihydrate and its deuterated analogue were recorded in the solid phase. The molecular geometry and vibrational frequencies of Bis(melaminium) terephthalate dihydrate in the ground state have been calculated by using the density functional method (B3LYP) with 6-31++G(d,p) basis set. The results of the optimized molecular structure are presented and compared with the experimental X-ray diffraction. The molecule contains the weak hydrogen bonds of N-H···O, N-H···N and O-H···O types, and those bonds are calculated with DFT method. In addition, molecular electrostatic potential, frontier molecular orbitals and natural bond orbital analysis of the title compound were investigated by theoretical calculations. The lack of the second harmonic generation (SHG) confirms the presence of macroscopic center of inversion.

Crystal structure, spectroscopic investigations and density functional studies of 4-(4-methoxyphenethyl)-5-benzyl-2H-1,2,4-triazol-3(4H)-one monohydrate.

The triazol compound 4-(4-methoxyphenethyl)-5-benzyl-2H-1,2,4-triazol-3(4H)-one monohydrate (I) has been synthesized and characterized by (1)H NMR, (13)C NMR, IR, and X-ray single-crystal determination. The molecular geometry, vibrational frequencies and gauge including atomic orbital (GIAO) (1)H and (13)C NMR chemical shift values of (I) in the ground state have been calculated using the density functional method (B3LYP) with the 6-31G(d) basis set. The calculated results show that the optimized geometry can well reproduce the crystal structure, and the theoretical vibrational frequencies and chemical shift values show good agreement with experimental values. The energetic behavior of (I) in solvent media was examined using the B3LYP method with the 6-31G(d) basis set by applying the Onsager and the polarizable continuum model (PCM). The predicted non-linear optical properties of (I) are greater than ones of urea. In addition, DFT calculations of molecular electrostatic potentials, frontier molecular orbitals and thermodynamic properties of (I) were carried out at the B3LYP/6-31G(d) level of theory.

Quantum-chemical, spectroscopic and X-ray diffraction studies of (E)-2-[(2-Bromophenyl)iminomethyl]-4-trifluoromethoxyphenol.

The Schiff base compound (E)-2-[(2-Bromophenyl)iminomethyl]-4-trifluoromethoxyphenol has been synthesised and characterised by IR, UV-vis, and X-ray single-crystal determination. The molecular geometry from X-ray determination of the title compound in the ground state has been compared using the Hartree-Fock (HF) and density functional theory (DFT) with the 6-311++G(d,p) basis set. The calculated results show that the DFT and HF can well reproduce the structure of the title compound. Using the TD-DFT and TD-HF methods, electronic absorption spectra of the title compound have been predicted and good agreement with the TD-DFT method and the experimental determination was found. The predicted nonlinear optical properties of the title compound are much greater than those of urea. In addition, DFT calculations of the title compound, molecular electrostatic potential (MEP), natural bond orbital (NBO), and thermodynamic properties were performed at B3LYP/6-311++G(d,p) level of theory.

2-Ethyl-N-[(5-nitro-thio-phen-2-yl)methyl-idene]aniline.

In the title compound, C(13)H(12)N(2)O(2)S, the dihedral angle between the benzene and thio-phene rings is 36.72 (8)°. An inter-molecular C-H⋯π inter-action contributes to the stability of the crystal structure.

Crystal structure, spectroscopy, and quantum chemical studies of (E)-2-[(2-chlorophenyl)iminomethyl]-4-trifluoromethoxyphenol.

The Schiff base compound (E)-2-[(2-chlorophenyl)iminomethyl]-4-trifluoromethoxyphenol has been synthesized and characterized by IR, UV-vis, and X-ray single-crystal determination. The molecular geometry from X-ray experiment in the ground state has been compared using the density functional theory (DFT) with the 6-311++G(d,p) basis set. The calculated results show that the DFT can well reproduce the structure of the title compound. Using the TD-DFT method, electronic absorption spectra of the title compound have been predicted, and a good agreement is determined with the experimental ones. To investigate the tautomeric stability, optimization calculations at the B3LYP/6-311++G(d,p) level were performed for the enol and keto forms of the title compound. Calculated results reveal that its enol form is more stable than its keto form. The predicted nonlinear optical properties of the title compound are much greater than those of urea. The changes of thermodynamic properties for the formation of the title compound with the temperature ranging from 200 to 500 K have been obtained using the statistical thermodynamic method. At 298.15 K, the change of Gibbs free energy for the formation reaction of the title compound is -824.841 kJ/mol. The title compound can spontaneously be produced from the isolated monomers at room temperature. The tautomeric equilibrium constant is also computed as 3.85 × 10(-4) at 298.15 K for enol↔keto tautomerization of the title compound. In addition, a molecular electrostatic potential map of the title compound was performed using the B3LYP/6-311++G(d,p) method.

(2-Hy-droxy-eth-yl)triphenyl-phospho-nium chloride.

In the crystal structure of the title compound, C(20)H(20)OP(+)·Cl(-), the cations and anions are linked by inter-molecular C-H⋯Cl and O-H⋯Cl hydrogen bonds into chains running parallel to the b axis. In the cation, the hy-droxy-ethyl group is disordered over two orientations with site-occupancy factors of 0.554 (4) and 0.446 (4).

Ethyl 4-(3-ethyl-5-oxo-4,5-dihydro-1H-1,2,4-triazol-4-yl)benzoate.

In the title compound, C(13)H(15)N(3)O(3), the dihedral angle between the two aromatic ring is 51.06 (1)°. In the crystal, mol-ecules are connected by pairs of N-H⋯O hydrogen bonds into centrosymmetric dimers.

1-Benzoyl-methyl-3-(2-thienylmeth-yl)-4-(2-thienylmethyl-eneamino)-1H-1,2,4-triazol-5(4H)-one.

In the title compound, C(20)H(16)N(4)O(2)S(2), one of the thio-phene rings is disordered [occupancy ratio 0.710 (4):0.290 (4)] and the disorder is of the flip type. An intra-molecular C-H⋯O hydrogen bond generates a six-membered ring with an S(6) motif.

2-Amino-4-nitro-phenol monohydrate.

The title compound, C(6)H(6)N(2)O(3)·H(2)O, crystallizes with two formula units in the asymmetric unit. The mol-ecules are essentially planar with the nitro groups twisted slightly out of the ring planes [maximum deviations from the ring plane of 0.13 (2) and 0.22 (2) Šin the two mol-ecules]. The respective O-N-C-C torsion angles are 6.0 (4) and 12.5 (4)°. In the crystal structure, mol-ecules are linked by inter-molecular N-H⋯O, C-H⋯O, O-H⋯O and O-H⋯N inter-actions into a three-dimensional network.

4-(4-Meth-oxy-pheneth-yl)-3-methyl-1H-1,2,4-triazol-5(4H)-one.

The dihedral angle between the two rings in the title compound, C(12)H(15)N(3)O(2), is 49.03 (1)°. The crystal structure is stabilized by inter-molecular N-H⋯O and C-H⋯O hydrogen bonds and π-π stacking inter-actions between the triazole rings with a centroid-centroid distance of 3.394 Å.

Experimental and quantum chemical calculational studies on 2-[(4-Fluorophenylimino)methyl]-3,5-dimethoxyphenol.

The Schiff base compound, 2-[(4-Fluorophenylimino)methyl]-3,5-dimethoxyphenol, has been synthesized and characterized by IR, electronic spectroscopy, and X-ray single-crystal determination. Molecular geometry from X-ray experiment of the title compound in the ground state have been compared using the Hartree-Fock (HF) and density functional method (B3LYP) with 6-31G(d) basis set. Calculated results show that density functional theory (DFT) and HF can well reproduce the structure of the title compound. The energetic behavior of the title compound in solvent media has been examined using B3LYP method with the 6-31G(d) basis set by applying the polarizable continuum model (PCM). The total energy of the title compound decrease with the increasing polarity of the solvent. By using TD-DFT and TD-HF methods, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental ones is determined. In addition, DFT calculations of the title compound, molecular electrostatic potential (MEP), natural bond orbital (NBO), and thermodynamic properties were performed at B3LYP/6-31G(d) level of theory.