Diaquabis(5-methoxyindole-2-carboxylato)bis(3-picoline)nickel(II) Complex: Synthesis,Characterization, XRD,TGA, DFT and HSA

A new complex of diaquabis(5-methoxyindole-2-carboxylato)bis(3-picoline)nickel(II) (Ni(5-MeOI2CA)₂(3-pic)₂(H₂O)₂), was synthesized for the first time and characterized by elemental analysis, FT-IR and electronic spectroscopy (UV-Vis) and single-crystal X-ray diffraction (XRD) techniques. The thermal degradation of the Ni(II) complex was investigated using thermogravimetric and differential thermal analyses techniques in oxygen atmosphere. The molecular structure of the complex was determined by single crystal X-ray diffraction technique. Hirshfeld surface analysis (HSA) investigated the packing modes and intermolecular interactions in molecular crystals, as they provide a visual picture of intermolecular interactions. In addition, all computational studies at B3LYP/6-311++G(d,p) were carried out for theoretical characterization of Ni(II) complex. The optimized geometry results, which were well represented the X-ray data, were shown that the chosen of DFT/B3LYP/6-311++G(d,p) was a successful choice for title compound. After a successful optimization, FMOs, chemical activity, non-linear optical properties (NLO), molecular electrostatic potential (MEP), Mulliken population (MPA), natural population analyses (NPA), Fukui function analysis (FFA) and natural bond orbital analysis (NBO), which could not obtained by experimental ways, were calculated and investigated. The computed of net charges and chemical activity studies which helped to identifying the electrophilic/nucleophilic nature.     

Crystal structure,spectroscopic investigations,and density functional studies of (Z)-2-(1H-imidazol-1-yl)-1-(3-methyl-3-mesitylcyclobutyl)ethanone oxime

The title molecule, (Z)-2-(1H-imidazol-1-yl)-1-(3-methyl-3-mesitylcyclo-butyl)ethanone oxime (C₁₉ H₂₅ N₃ O), was prepared and characterized by¹H-Nuclear magnetic resonance (NMR), ¹³C-NMR, infrared spectroscopic methods, and X-ray single-crystal determination. The compound crystallizes in the orthorhombic space group P c c n with a = 31.4660(17) Å, b = 11.2140(7) Å, and c = 10.0710(8) Å. In addition to molecular geometry from X-ray determination, vibrational frequencies and gauge, including atomic orbital, ¹H- and ¹³C-NMR chemical shift values of the title compound in the ground state, were calculated using the density functional method with the 6-31G(d) basis set. The calculated results show that the optimized geometries can well reproduce the crystal structure. Besides, the theoretical vibrational frequencies and chemical shift values show good agreement with experimental values. The predicted nonlinear optical properties of the title compound are greater than those of urea. Density functional theory calculations of molecular electrostatic potentials, frontier molecular orbitals, and thermodynamic properties of the title compound were carried out at the B3LYP/6-31G(d) level of theory.     

Structural,spectroscopic properties and theoretical studies of (E)-1-(4-Bromophenyl)-3-(2,3,4-trimethoxyphenyl)prop-2-en-1-one as a potential anti-oxidant agent

The new chalcone compound namely (E)-1-(4-Bromophenyl)-3-(2,3,4-trimethoxyphenyl)prop-2-en-1-one (C₁₈H₁₇BrO₄) is crystallized in the monoclinic crystal system of P2₁/c space group. The unit cell dimensions are: a = 8.0753 (10) Å, b = 21.873 (3) Å, c = 9.3362 (12) Å, α = 90°, β = 99.369 (2), γ = 90° and Z = 4. The single crystal was grown using slow evaporation solution growth technique. The newly synthesized compound was characterized by using IR, ¹H- and ¹³C-NMR, UV-Vis and single crystal X-ray diffraction analyses. Quantum chemical method of Density Functional Theory (DFT) with B3LYP/6-311++G(d,p) has been employed to study the structural and spectral properties of the compound. The electronic absorption spectrum was calculated using the time dependent functional theory (TDDFT) method. The most stable conformer of the title chalcone is identified from the computational results. Hirshfeld surface analysis with fingerprint plots has been used as a graphical tool for visualization and understanding of intermolecular interactions. Intermolecular C?H····O interaction observed stabilize the crystal structure, forming an infinite one dimensional column. The effect of this intermolecular interaction in the solid state can be seen in the difference between the experimental and the theoretically optimized geometrical parameters. The crystal is transparent in the entire visible region and absorptive in the UV region. Information about the size, shape, charge density distribution and site of chemical reactivity of the molecule has been obtained by mapping electron potential (MEP). The other molecular properties like charge transfer are explain using Mulliken population analysis. The antioxidant test indicated that the 2,3,4-trimethoxy substitution on the bromide chalcone to be one of the favorable modification to enhance its metal chelating activity.     

X-ray crystallographic analysis and NMR study of (Z)-3(2-hydroxyphenyl)-1(4-methoxyphenyl)-3-oxo-prop-1-en-1-ol

The molecular structure of the title compound has been determined by X-ray crystallography. The enol form is present in the solid state and each of the two molecules in the asymmetric unit possesses two intramolecular hydrogen bonds. The delocalization of double bonds results in an almost planar molecule. Evidence to support the enol configuration in solution is presented from an NMR investigation.     

Quantum Chemical,Spectroscopic, and X-Ray Diffraction Studies of N-diphenylphosphino-4-methylpiperidine Selenide (1)

The title molecule, N-diphenylphosphino-4-methylpiperidine selenide(1), was prepared and characterized by elemental analysis, ¹H-NMR, ³¹P-{¹H} NMR, IR, and X-ray single-crystal determination. The compound crystallizes in the monoclinic space group P 2₁/c. In addition to the molecular geometry from X-ray determination, vibrational frequencies and gauge, including atomic orbital (GIAO) ¹H- and ³¹P-{¹H} NMR chemical shift values of the title compound (1) in the ground state, were calculated using the Hartree–Fock and density functional methods with the 6-31G(d, p) basis set. The calculated results show that the optimized geometries can well reproduce the crystal structures. Besides, the theoretical vibrational frequencies and chemical shift values show good agreement with experimental values. The predicted nonlinear optical (NLO) properties of the title compound are greater than those of urea. In addition, density functional theory (DFT) calculations of the molecular electrostatic potentials (MEPs), frontier molecular orbitals (FMOs) of the title compound were carried out at the B3LYP/6-31G(d) level of theory.     

Molecular structure,DFT studies,Hirshfeld surface analysis,energy frameworks,and molecular docking studies of novel (E)-1-(4-chlorophenyl)-5-methyl-N′-((3-methyl-5-phenoxy-1-phenyl-1H-pyrazol-4-yl) methylene)-1H-1, 2, 3-triazole-4-carbohydrazide

Abstract

The synthesis of the compound and its crystal structure having a monoclinic crystal system has been reported earlier. Optimized bond lengths and angles are showing good agreements with experimental data using DFT/B3LYP method. Energy of highest occupied molecular orbital and lowest unoccupied molecular orbital has been predicted to analyze the stabilities of compound. Crystal explorer 17.5 helps to visualize intermolecular interactions and its contributions to each interaction within molecule. The preeminence of dispersion energy component over the other components was established by interaction energy calculations and lattice energy framework analysis using same software. The molecular docking study was performed for molecule using AutoDock software.     

Molecular and crystal structure of 2-{(<Emphasis Type="Italic">E</Emphasis>)-[(4-Methylphenyl)imino]methyl}-4-nitrophenol: A redetermination

The crystal structure of the title compound, C₁₄H₁₂N₂O₃, was recently determined as a mixture of its neutral (OH containing) and zwitterionic (NH containing) forms, in a 0.60 (4): 0.40 (4) ratio using the X-ray determination. In this study, the title compound has been characterized by FT-IR and X-ray diffraction. The redetermination showed that the title compound has only enol (OH) form because of lack of the NH stretching vibration in FT-IR spectrum. In addition, the molecular structure and tautomerism of the title compound have been discussed.     

Synthesis and structure of chiral ligand [(<Emphasis Type="Italic">S</Emphasis>)-1-(((<Emphasis Type="Italic">S</Emphasis>)-1-methylpyrrolidin-2-yl) methyl) pyrrolidin-2-yl] diphenylmethanol

The title compound (C₂₃H₃₀N₂O), a chiral ligand, has been successfully synthesized from a natural proline. FTIR spectrum has been discussed. DFT (B3LYP) method has been used to determine the structure. With the basis set of the 6–311G^* quality, the DFT calculated bond parameters and harmonic vibrations are predicted in very good agreement with experimental data.

X-Ray diffraction and vibrational spectroscopic study of 2-chloro-N-{4-[3-(2,5-dimethylphenyl)-3-methylcyclobutyl]-thiazol-2-yl}-acetamide

The title compound C₁₈H₂₁ClN₂SO crystallizes with Z = 4 in space group P2₁/c. The structure of the title compound was characterized by ¹H-NMR, ¹³C-NMR, IR and single crystal diffraction. There are an intermolecular N-H…O hydrogen bond and a C-H…π interactions in crystal packing. In addition to the molecular geometry and packing obtained from X-ray experiment, the molecular geometry and vibrational frequencies of the title compound in ground state have been calculated using density functional theory method DFT (B3LYP) with 6-31G (d, p) basis set. Calculated frequencies, bond lengths, angles and dihedral angles are in good agreement with the corresponding experimental data.     

Synthesis, Molecular Structure and Antioxidant Activity of (E)-4-[Benzylideneamino]-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one, a Schiff Base Ligand of 4-Aminoantipyrine

Abstract  

In this study, the title compound, C₁₈H₁₇N₃O (M _r = 291.35), was synthesized by the condensation reaction of 4-amino-1,5-dimethyl-2-phenylpyrazole-3-one and benzaldehyde. Single-crystal X-ray diffraction data revealed that this compound adopts a trans configuration around the central C=N double bond. It crystallizes in the monoclinic, space group P2₁/c with a = 12.9236(17) ?, b = 6.8349(9) ?, c = 17.072(2) ?, β = 90.316(3)°, V = 1508.0(3) ?³, Z = 4, D _c = 1.283 Mg/m³, F(000) = 616, μ = 0.082 mm⁻¹, R = 0.0442, and wR = 0.0936. Two different planes exist within the molecule; e.g. the pyrazolone and benzylidene groups attached to C9 of the pyrazolone ring are almost coplanar, whereas the phenyl group attached to the N1 of the pyrazolone ring is in another plane. Density functional theory (DFT) and time-dependent DFT calculations were performed to predict the electronic structure and absorption spectra of (E)-4-[benzylideneamino]-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one, a schiff base ligand of 4-aminoantipyrine using B3LYP/6-311G basis set on the AM1 optimized geometry. The predicted vibrational frequencies using the B3LYP/6-311G method were in strong agreement with the experimental IR spectra. The time dependent DFT calculations were used to evaluate the electronic absorption spectrum and three electron transition bands, which were mainly derived from the contribution of n → π* and π → π* transitions, were observed in both the experimental and predicted UV–Vis spectra. A maximum emission band at 370 nm was observed in the fluorescence spectra of the title compound. In addition, the title compound showed good DPPH antioxidant activity.     

Crystal structure of 1-(2-hydroxyphenyl)-3-(2-thiomethoxyphenyl)-1,3-propanedione,C16H14O3S

The crystal structure of the enol tautomer of 1-(2-hydroxphenyl)-3-(2-thiomethoxyphenyl)-1,3-propanedione C₁₆H₁₄O₃S, was determined from X-ray crystallography. The finalR value was 5.99% based on 1945 unique observed reflections. The crystals are monoclinic,P2₁/c, witha=7.406(6),b=8.585(6),c=21.992(4) Å,=93.42(2),D _c =1.36 g cm^–3 forz=4. The compound is present in the solid state as a unique enol tautomer.There are two short, intramolecular OO contacts of 2.553(4) and 2.577(4) Å. Both the phenol and the enol H atoms are asymmetrically located with respect to the O atoms.     

Crystal structure,spectroscopic properties,and DFT studies of 2-(2-hydroxyphenyl)benzo[d]oxazole-6-carbaldehyde

The title compound 2-(2-hydroxyphenyl)benzo[d]oxazole-6-carbaldehyde (1a) was synthesized and characterized by single-crystal X-ray diffraction. Compound 1a possesses intramolecular C–H···O and O–H···N hydrogen bonds, which generate S(5) and S(6) rings, respectively. Intermolecular π–π stacking is observed in the crystal structure, which links a pair of molecules into a cyclic centrosymmetric dimer. The crystal structure is further stabilized by three different intermolecular C–H···O hydrogen bonds, which link the molecules into a continuous three-dimensional framework. Its spectroscopic properties and complementary density functional theory (DFT) calculations are also reported.     

Hexakis(4-phormylphenoxy)cyclotriphosphazene: X-ray and DFT-calculated structures

The crystal structure of hexakis(4-phormylphenoxy)cyclotriphosphazene is determined by using X-ray diffraction and then the molecular structure is investigated with density functional theory (DFT). X-Ray study shows that the title compound has C-H…π interaction with phosphazene ring. The molecules in the unit cell are packed with Van der Waals and dipole-dipole interactions and the molecules are packed in zigzag shaped. Optimized molecular geometry is calculated with DFT at B3LYP/6-311G(d,p) level. The results from both experimental and theoretical calculations are compared in this study.     

Synthesis,Crystal Structure,Spectroscopic and Electronic Properties of (E)-Trans-2-(2-(Biphenyl-4-ylmethylene)Hydrazinyl)-4-(3-Methyl-3-Phenylcyclobutyl)Thiazole

Abstract  

A new compound of (C₂₇H₂₅N₃S) has been synthesized and characterized by ¹H NMR, ¹³C NMR, IR, UV-Visible spectroscopy, and single crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P2₁/c and crystals of (I) were found approximately 0.5:0.5 ratio to be twinned. The crystal structure is stabilized by N–H···N inter molecular hydrogen bonding. In addition to the molecular geometry and dimeric structure from X-ray experiment, the optimized molecular geometry for monomer and dimer, vibrational frequencies, atomic charges distribution, and total energies of the title compound in the ground state have been calculated using ab initio method. Density Functional Theory (B3LYP) and Hartree-Fock (HF) methods with basis sets 6-31G(d, p) and 3-21G were used in the calculations. Calculated frequencies are in good agreement with the corresponding experimental data. UV-Vis absorption spectra of the compound have been ascribed to their corresponding molecular structure and electrons orbital transitions.     

Synthesis,crystal structure,HF and DFT calculations of 1-(2-chlorobenzyl)-N-(1-(2-chlorobenzyl)-4,5-dihydro-1H-imidazol-2-yl)-1H-benzimidazol-2-amine

The titled compound (1), has been synthesized and characterized by IR and ¹H-NMR spectroscopy, and single crystal X-ray diffraction. The compound crystallizes in the triclinic space group P-1. The crystal structure is stabilized by C-H…π and aromatic π-π interactions. There are also intramolecular N-H…N and C-H…N hydrogen bonds in the molecule. The use of quantum chemical calculations to characterise and optimise the choice of material is illustrated by ab initio treatments. Vibrational frequencies and LUMO-HOMO energy difference of 1 have also been investigated by Density functional theory (DFT) and Hartree-Fock (HF) calculations. Calculated frequencies are in good agreement with the corresponding experimental data.     

Chemical Synthesis,X-ray Crystallography,Hirshfeld Surface Analysis,and Molecular Docking Studies of (E)-2-(((3-Bromophenyl)imino)methyl)-5-(diethylamino)phenol Schiff Base

Crystallography Reports - The title Schiff base compound (I), C17H19BrN2O, has been synthesized by the reaction of 4-(diethylamino)-2-hydroxybenzaldehyde and 3-bromoaniline. The dihedral angle...     

(<Emphasis Type="Italic">E</Emphasis>)-2-[(2-Bromophenylimino)methyl]-5-methoxyphenol: X-ray and DFT-calculated structures

The crystal structure of (E)-2-[(2-Bromophenylimino)methyl]-5-methoxyphenol is determined by using X-ray diffraction and then the molecular structure is investigated with density functional theory (DFT). X-Ray study shows that the title compound has a strong intramolecular O-H…N hydrogen bond and three dimensional crystal structure is primarily determined by C-H…π and weak van der Waals interactions. The strong O-H…N bond is an evidence of the preference for the phenol-imine tautomeric form in the solid state. Optimized molecular geometry is calculated with DFT at the B3LYP/6-31G(d,p) level. The IR spectra of compound were recorded experimentally and calculated to compare with each other. The results from both experiment and theoretical calculations are compared in this study.     

Experimental and Semi-Empirical and DFT Calculational Studies on (<Emphasis Type="Italic">E</Emphasis>)-2-[(2,4-Dichlorophenylimino) methyl]-<Emphasis Type="Italic">p</Emphasis>-cresol

Abstract  

The molecular and crystal structure of the title compound, C₁₄H₁₁Cl₂NO, has been determined by X-ray single crystal diffraction technique. The compound crystallizes in the orthorhombic, space group Pbca with unit cell dimensions a = 7.5537(10) ?, b = 11.5518(13) ?, c = 29.760(4) ?, M _r  = 280.14, V = 2596.8(6) ?³, Z = 8, R ₁ = 0.065 and wR ₂ = 0.191. The title compound exists in the enol–imine tautomeric form with a strong intramolecular O–H···N hydrogen bond. The dihedral angle between the two benzene rings is 37.66(15)°. The asymmetric unit in the crystal structure contains only one neutral molecule. Calculational studies were performed by using AM1, PM3, PM6 semi-empirical and DFT methods. Geometry optimizations of compound have been carried out by using three semi-empirical methods and DFT method and bond lengths, bond and torsion angles of title compound have been determined. Dipole moments (Debye) and the energy parameters of compound (kcal/mol) were calculated by using above mentioned calculation methods. Atomic charge distribution has been obtained from AM1, PM3, PM6 and DFT. In order to determine conformational flexibility on the molecule, molecular energy profile of the title compound was obtained with respect to the selected torsion angle T(N1–C7–C1–C2), which is varied from −180° to +180° in every 10 via PM3 semi-empirical method.     

Conformational studies of 1-4-bis(3,5-di-<Emphasis Type="Italic">tert-</Emphasis> butylpyrazolyl-1-carbonyl)benzene

In the solid state structure of the title compound (1) the carbonyl group is coplanar with neither the phenyl group nor pyrazolyl moiety. The electron density delocalization between these three aromatic parts of the molecule is minimal. The molecular conformation about the C–N bond of the O=C–N–N fragment is E due to electrostatic reasons. Density Functional Theory (DFT) and Natural Bond Orbital Theory (NBO) studies of related (pyrazolyl-1-carbonyl)benzenes are presented.     

5-溴-2-(4-甲基哌啶-1-基)嘧啶的晶体结构及密度泛函理论研究

嘧啶类衍生物在医药、化工和功能材料等领域有着重要应用。在药物研发,特别是抗癌药物研发领域中,5-溴-2-(4-甲基哌啶-1-基)嘧啶是一种含嘧啶环的重要中间体。本文通过一步芳香亲核取代反应合成了5-溴-2-(4-甲基哌啶-1-基)嘧啶,经溶液结晶法获得其单晶体,并进行了晶体学分析(晶系:正交晶系,空间群:P2₁2₁2₁,晶胞:a=10.181 42(6) nm, b=17.620 0(8) nm, c=10.179 02(5) nm,Z=4,ρ_c＝1.478 g·cm^-3,R=0.056 6,wR=0.168 8)。标题化合物的最优结构和前线轨道能量在B3LYP/6-311G(d, p)模式下使用密度泛函理论(DFT)计算得到,经DFT优化的结果与实验确定的数据相近。此外,为进一步揭示标题化合物的物理化学性质,通过DFT进一步研究了分子的静电式和前线分子轨道。