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.     

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.     

A new supramolecular cocrystal of 2-amino-3-bromopyridine with 4-methylbenzoic acid: Synthesis,structural, spectroscopic characterization and comparative theoretical studies

The 1:1 cocrystal of 2-amino-3-bromopyridine (2A3BP) with 4-methylbenzoic acid (4MBA) has been prepared by slow evaporation method in methanol, which was crystallized in monoclinic P2₁/c space group having two molecules in the asymmetric unit. The cocrystal has been characterized by single crystal X-ray analysis, FTIR, ¹H NMR, ¹³C NMR, and Powder XRD. Theoretical investigations have been calculated by HF and density function (B3LYP) method with the 6-311+G(d,p) basis set. The vibrational frequencies together with the ¹H NMR and ¹³C NMR chemical shifts have been calculated on the fully optimized geometry of 1. Theoretical calculations of bond parameters, harmonic vibration frequencies, and isotropic chemical shifts are in good agreement with the experimental results. Solvent-free formation of these cocrystal was confirmed by powder X-ray diffraction analysis. The crystal structure was stabilized by N_pyridine—H···O = C, C = O—H···N_pyridine and C—H···Br hydrogen bonding interactions.     

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.     

Synthesis,Crystallographic and Spectral Studies of 3-(4-(Phenylamino) Phenylamino)Cyclohex-2-Enone

Abstract  

The title compound, 3-(4-(phenylamino)phenylamino)cyclohex-2-enone, β-enaminone of 1,3-cyclohexanedione and p-amino diphenylamine (C₁₈H₁₈N₂O) was prepared and characterized by ¹H-NMR, ¹³C-NMR, Elemental analysis and IR spectroscopy as well as single crystal X-ray diffraction. These results indicate the predominance of the keto-enol tautomerism. Molecular conformation around the central disubstituted benzene ring is affected by the tautomerism and two steric effects between side molecular groups and mono substituted benzene ring. Electron delocalizations due to these effects have been observed in the molecular structure, the structure being stabilized by some intermolecular hydrogen bonds.     

Synthesis,Crystal Structure and Characterization of (Z)-2-N′-hydroxyisonicotinamidine

The compound (Z)-2-N′-hydroxyisonicotinamidine, (2) was synthesized and characterized by ¹H NMR, FT-IR, FAB-Mass, UV-Visible Spectra, and elemental Analysis. Its molecular structure was solved by single crystal X-ray diffraction method. The title molecule, C₆H₇N₃O is crystallized in the orthorhombic crystal system with the space group Pna2₁ and with unit cell parameters a = 12.5664(8) Å, b = 8.8622(6) Å, c = 5.7953(4) Å, α = 90°, β = 90°, γ = 90°, and Z = 4. The molecular and crystal structure of the title molecule is stabilized by an intramolecular interaction of the type N—H···O, and the intermolecular interactions of types N—H···N and O—H···N.     

Synthesis, Crystal and Molecular Structure of 1-(2-Chlorobenzyl)-2-methylthio-1H-benzimidazole

Abstract  

1-(2-Chlorobenzyl)-2-methylthio-1H-benzimidazole compound has been synthesized and characterized by elemental analysis, IR and ¹H-NMR spectroscopy and single crystal X-ray diffraction. The compound crystallizes in the triclinic space group P-1 with unit cell parameters a = 17.201 ?, b = 5.873 ?, c = 24.791 ?, α = 67.410(10)°, β = 74.083(11)°, γ = 81.858(12)°. In the crystal packing, no classic hydrogen bonds are founded, but C–H···π interactions are being between the molecules. The molecular geometry and vibrational frequencies of (C₁₅H₁₃ClN₂S) in the ground state have been calculated by using Hartree–Fock (HF) and Density Functional Method (DFT/B3LYP) with 6-31G(d) basis set. The optimized geometric bond lengths and bond angles obtained by using HF and DFT (B3LYP) show the best agreement with the experimental data.     

Synthesis,Crystal Structure and Spectroscopic Characterization of {6-[2-(2-chlorophenyl)-1,3-thiazol-4-yl]-2-oxo-1,3-benzothiazol-3(2<Emphasis Type="Italic">H</Emphasis>)-yl}acetic acid

Abstract  

The title compound {6-[2-(2-chlorophenyl)-1,3-thiazol-4-yl]-2-oxo-1,3-benzothiazol-3(2H)-yl}acetic acid was prepared and characterized by elemental analyses, FT-IR, ¹H NMR spectroscopy, X-ray diffraction. A quantum-chemical calculation was performed using the CNDO method. In the title compound, C₁₈H₁₁ClN₂O₃S₂, the crystal structure is stabilized by intermolecular hydrogen bonds (C–H···O=C) to form centrosymmetric R₂² R_{2}^{2} (16) dimers and the C–H···O, O–H···N, and C–H···N interactions generating the graph set motifs R₂² R_{2}^{2} (9) and R₂² R_{2}^{2} (22).     

Synthesis,structural characterization,and DFT calculations of 3-buthyl-4-(3-methyl-3-mesitylcyclobut-1-yl)-1,3-thiazole-2(3<Emphasis Type="Italic">H</Emphasis>)-thione

The title compound, C₂₁H₂₉NS₂, has been synthesized and its crystal structure has been determined from single crystal X-ray diffraction data. Crystals are monoclinic, a = 11.4923(8), b = 13.1842(7), c = 14.6583(8) Å, β = 109.983(6)°, sp. gr. P2₁/c, Z = 4. Mesityl and thiazole groups are in cis positions with respect to the cyclobutane ring. The cyclobutane ring is puckered, with a dihedral angle of 26.6(2)° between the two three-atom planes. The crystal structure involves one weak intermolecular C–H···S hydrogen-bond. The molecular geometry was also optimized using density functional theory (DFT/B3LYP) method with the 6-311G(d, p) basis set in ground state. Geometric parameters (bond lengths, bond angles and torsion angles) and vibrational assignments have been calculated theoretically and compared with the experimental data.     

Synthesis,Crystal and Calculated Structure,and Biological Activity of 2-((6-Bromo-2-methoxyquinolin-3-yl) (phenyl)methyl)-2,3,7,7a-tetrahydro-3a,6-epoxyisoindol-1(6H)-one

Abstract  

The title compound, C₂₅H₂₁BrN₂O₃, was synthesized and structurally characterized by elemental analysis, IR, MS, ¹H NMR and single crystal X-ray diffraction. The crystal is of orthorhombic system, space group Pbca with a = 11.706(2) ?, b = 18.038(4) ?, c = 20.369(4) ?, α = 90.00°, β = 90.00°, γ = 90.00°, V = 4301.0(15) ?³, Z = 8, Dc = 1.474 g/cm³, F (000) = 1952.0, μ(MoKα) = 1.941 mm⁻¹, the final R ₁ = 0.0670 and wR ₂ = 0.2319 for reflections with I > 2σ(I). The crystal structure is stabilized by un-classical hydrogen-bonding C–H···O forming a three-dimensional network. The optimized geometric bond lengths and bond angles obtained by using density functional theory have been compared with X-ray diffraction values. In addition, the preliminary biological test showed that the title compound had anti-Mycobacterium phlei 1180 activity.     

Synthesis,characterization, and crystal structure analysis of 2-(2-hydroxy-3-methoxyphenyl)-1-(4-chlorophenyl)-4,5-diphenyl-1h-imidazole

The substituted imidazole C₂₈H₂₁ClN₂O₂, was prepared via multicomponent reactions and the product crystallized using dimethylformamide. The structure of the compound was established by elemental analysis, Fourier transform infrared spectroscopy, thermogravimetric analysis, UV-visible, proton nuclear magnetic resonance spectroscopy, and single-crystal X-ray diffraction. The molecule is crystallized in the tetragonal crystal system with the space group P4₃2₁2 and with unit cell parameters a = 12.246(4) Å, b = 12.246(4) Å, c = 31.781(2) Å, and Z = 8. The molecular and crystal structures of the title molecule are stabilized by the intramolecular interactions, O-H···N and C-H···N, and intermolecular interaction, C-H···O.     

Crystal Structure of 3-(4-Methoxy-benzylidene)-isothiochroman-4-one

Abstract  

The title compound, 3-(4-methoxy-benzylidene)-isothiochroman-4-one (C₁₇H₁₄O₂S) was prepared from the reaction of isothiochroman-4-one with benzaldehyde in the presence of small amount of HCl. The structure of the synthesised compound was determined by IR, ¹H NMR and X-ray crystallography. The structure was solved in monoclinic, space group P2₁/n with a = 3.9773 (7) Å, b = 10.918 (2) Å, c = 30.609 (6) Å, β = 90.615 (3)°, V = 1329.1 (4) Å³, Z = 4 and with R _int = 0.047. The bicyclic ring of isothiochroman-4-one moiety does not adopt a planar geometry. The molecular conformation is stable via C10–H···O1 and C16–H···S1 intramolecular hydrogen-bonding interactions. These contacts involve molecules in an extended two-dimensional sheet to the bc plane.     

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.     

Synthesis and Crystal Structure of a Complex of Palladium(II) with 2-Hydroxyimino-3-(2-hydrazonopyridyl)-butane

Abstract  

Schiff-base condensation of an equimolar proportion of diacetyl-monoxime and 2-hydrazino pyridine in methanol gives rise to 2-hydroxyimino-3-(2-hydrazonopyridyl)-butane (HL). The ligand has been characterised by FT-IR, ¹H NMR and UV–Vis spectra. Reaction of 1:1 stoichiometric proportion of HL with Na₂[PdCl₄] in methanol affords a mononuclear palladium(II) compound, [PdLCl]·H₂O (1). The compound is characterised by C, H and N analyses, FT-IR, conductivity measurement, UV–Vis spectra, thermal analysis and magnetic susceptibility measurement. The X-ray crystal structure of the title compound (1) has been determined. The compound crystalises in the triclinic space group P[`1] P\overline{1} with a = 7.3033(3), b = 9.4139(4), c = 9.4445(5) ?, α = 79.789(3), β = 68.285(2), γ = 77.978(3)o, V = 586.42(5) ?³ and Z = 2. Pd(II) is in ‘N₃Cl’ coordination chromophore. The geometry around Pd(II) is square-planar. The compound is essentially diamagnetic.     

Synthesis Characterization and Crystal Structure of 2-(3,4,5-trimethoxyphenyl)-1-(4-fluorophenyl)-4,5-diphenyl-1H-imidazole

The title compound, C₃₀H₂₅FN₂O₃, was prepared from the four-component one-pot condensation reaction and the product crystallized using dimethylformamide. The structure of the compound was established by elemental analysis, Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), UV-Visible, and single-crystal X-ray diffraction. The compound crystallizes in the triclinic crystal system with the space group Pī, with unit cell parameters a = 10.286(2) Å, b = 11.795(2) Å, c = 21.331(4) Å, α = 100.270(3)°, β = 90.093(3)°, γ = 90.062(3)°, and Z = 4. The crystal and molecular structure of the title molecule is stabilized by intra-molecular interactions of types C–H···N and C–H···O.     

Synthesis,characterization, single crystal X-ray diffraction and DFT studies of ethyl 5-methyl-1-phenyl-1H-pyrazole-4-carboxylate

The present study describes the synthesis, spectroscopic, and single crystal X-ray structural analysis of ethyl 5-methyl-1-phenyl-1H-pyrazole-4-carboxylate. The pyrazole ester of formula [C₁₃H₁₄N₂O₂] was prepared from the three-component one-pot condensation reaction of ethyl acetoacetate, N,N-dimethyldimethoxymethanamine, and phenyl hydrazine. The product was crystallized by using ethanol as solvent. The structure of the compound was confirmed by elemental analysis, Fourier transforms infrared (IR), thermogravimetric analysis, UV-visible (UV-Vis), ¹H NMR, and single-crystal X-ray diffraction studies. The gas-phase molecular geometry and the electronic structure-property of the molecule were calculated at the density functional theory. The frontier molecular orbitals, theoretical UV-Vis, and IR stretching vibrations were also reported. The compound crystallizes in the monoclinic system with the space group P2₁/c and Z = 4. The unit cell parameters are a = 12.141(3) Å, b = 13.934(4) Å, c = 7.2777(18) Å, and β = 97.816(14)⁰. The structure is stabilized by an intermolecular interaction of type C-H···O and the structure also involves C-H···π interactions.     

Synthesis,Crystal Structure,and Characterization of 2-Phenyl-N-(pyrazin-2-yl)Acetamide

The title compound, 2-Phenyl-N-(pyrazin-2-yl)acetamide, C₁₂H₁₁N₃O, was prepared by the coupling reaction and the product was crystallized by using toluene and methanol mixture(1:1) The structure of the compound was confirmed by elemental analysis, FTIR, ¹H NMR, thermogravimetric analysis, differential thermal analysis, UV-Visible spectroscopy, and single-crystal X-ray diffraction. The compound crystallizes in the monoclinic space group P 2₁/c with the following unit-cell parameters: a = 8.1614(10), b = 14.9430(13), c = 9.3877(9) Å, β = 103.653(12)°, and Z = 4. The crystal structure was solved by direct methods using single-crystal X-ray diffraction data collected at room temperature and refined by full-matrix least-squares procedures to a final R-value of 0.0465 for 1486 observed reflections. An intramolecular C&sbnd;H···O hydrogen bond generates an S(6) graph-set motif. In the crystal, molecules are linked by N&sbnd;H···O and C&sbnd;H···O hydrogen bonds, forming a two-dimensional network.     

Crystallographic and Conformational Analysis of [(<Emphasis Type="Italic">E</Emphasis>)-2-[(3-Chlorophenylimino)methy])-4-methoxyphenol]

Abstract  The crystal structure of C₁₄H₁₂ClNO₂ was determined by X-ray analysis. It crystallizes in the triclinic space group Pc with a = 12.5346(10) ?, b = 4.5101(3) ?, c = 12.0534(11) ?, α = 90.00o, β = 113.669(6)o, γ = 90.00o, Z = 2, Dx = 1.393 mg/m³, μ (MoK_α) = 0.298 mm⁻¹. The title compound is photochromic and molecule is non-planar. It adopts a phenol–imine tautomeric form with a strong intramolecular O–H···N hydrogen bond and a strong intermolecular C–H···O hydrogen bond. Minimum energy conformations AM1 were calculated as a function of the three torsion angles θ1(C10–C9–N1–C8), θ2(C9–N1–C8–C1) and θ3(N1–C8–C1–C6), varied every 10°. As in the X-ray experiment results, molecule has an angle that makes it non-planar between two aromatic rings in AM1 optimized geometry. Graphical Abstract  Molecular and crystal structure of [(E)-2-[(3-chlorophenylimino)methy])-4-methoxyphenol], C₁₄H₁₂ClNO₂, have been determined by single crystal X-ray diffraction study, and conformational analysis of the title molecule with respect to the selected torsion angle has been achieved by AM1 semi-empirical calculations.      

X-ray and Theoretical Studies of 2-((5-Amino-1,3,4-thiadiazol-2-yl)thio)-1-phenylethanone

The crystal structure of 2-((5-amino-1,3,4-thiadiazol-2-yl)thio)-1-phenylethanone was determined by X-ray diffraction method. The compound crystallizes in orthorhombic crystal system, sp. gr. Pbca. The atoms that constitute thiadiazole and phenyl rings do not form any significant deviation from the ring planes. Compound has two intermolecular N–H···N hydrogen bonds and one C–H···π interaction. Using DFT/B3LYP method with 6-31G(d), 6-311G(d), 6-311G(d, p), and 6-311++G(d, p) basis sets, the molecular geometry of the compound was optimised. Bond lenghts, bond angles, torsion angles, dihedral angles, and HOMO–LUMO were calculated from the optimised geometry of the compound. The results obtained by X-ray diffraction method were compared with the results obtained through four different basis sets. Total energy of the molecule was calculated for four different basis sets.     

The hydrogen bonding in 2-amino-3-cyano-4-(3-nitrophenyl)-4,6-dihydro-5H-pyrano[3,2-c]quinolin-5-one N,N-dimethylformamide solvate monohydrate

The crystal structure of 2-amino-3-cyano-4,6-dihydro-4-(3-nitrophenyl)-5H-pyrano[3,2-c]quinolin-5-one N,N-dimethylformamide solvate monohydrate is determined by room temperature X-ray diffraction. The title compound 1, C₂₂H₂₁N₅O₆, is triclinic, space group P-1, a=9.109(2) ?, b=11.340(2) ?, c=12.485(2) ?, α=70.02(1)°, β=69.36(1)°, γ=67.32(1)°, Z=2, V=1081.4(4) ?³. It is interesting that a bridge-like hydrogen bond O–H···O is formed between the title compound and solvent molecules of water with molecular ratio of 2:2 building a bi-layer framework. In addition, there are two other types of classical hydrogen bonds N–H···N and N–H···O in the crystal structure.Supplementary material Crystallographic data for the structure reported in this paper have been deposited with the Cambridge Crystallographic Data Centre as supplementary publication no. CCDC-275001. Copies of available material can be obtained, free of charge, on application to the Director, CCDC, 12 Union Road, Cambridge CB2 1EZ, UK, (fax: +44-(0) 1223–336033 or e-mail: deposit@ccdc.cam.ac.uk).