A Comparative X-ray Diffraction Study and Ab Initio Calculation on RU60358, a New Pyrethroid

The crystal structure of RU60358, C20H21NO3, has been determined using X-raydiffraction to establish the configuration and stereochemistry of the molecule around theC15-C16 triple bond. The compound crystallises in the orthorhombic space group P212121, a= 7.7575, b = 11.3182, c = 21.3529å, V = 1874.80å3 and Z = 4. The structure has beenrefined to a final R = 0.068 for the observed structure factors with I ≥ 3σ (I). The refinedstructure was found to be significantly non planar. A comparative study, using the ab initiocalculations of the structure at B3LYP/6-31G** levels of theory, shows good geometricalagreement with the X-ray diffraction data. Standard deviations between the calculated andexperimental bond values have been shown to be 0.01 å and 0.5° for bond angles.Vibrational wavenumbers were obtained from a normal mode analysis using the ab initiocalculations

Electron Charge Density Distribution from X-ray Diffraction Study of the M-Nitrophenol Compound in the Monoclinic Form

At room temperature, the m-Nitrophenol (m-NPH) appears in two polymorphicstructures: orthorhombic and monoclinic forms. In the present work, we shall focus on themonoclinic form of this compound which has a centrosymmetric structure with the spacegroup P21/n. The molecular dipole moment has been estimated experimentally. Highresolution single crystal diffraction experiment was performed at low temperature withMoKα radiation. The crystal structure was refined using the multipolar model of Hansen andCoppens (1978). The molecular electron charge density distribution is described accurately.The study reveals the nature of inter-molecular interactions including charge transfer andhydrogen bonds. In this crystal, hydrogen bonds of moderate strength occur between thehydroxyl group and the O atom in the nitro one

Electron Charge Density Distribution from X-ray Diffraction Study of the M-Nitrophenol Compound in the Monoclinic Form

Abstract: At room temperature, the m-Nitrophenol (m-NPH) appears in two polymorphic structures: orthorhombic and monoclinic forms. In the present work, we shall focus on the monoclinic form of this compound which has a centrosymmetric structure with the space group P21/n. The molecular dipole moment has been estimated experimentally. High resolution single crystal diffraction experiment was performed at low temperature with MoKα radiation. The crystal structure was refined using the multipolar model of Hansen and Coppens (1978). The molecular electron charge density distribution is described accurately. The study reveals the nature of inter-molecular interactions including charge transfer and hydrogen bonds. In this crystal, hydrogen bonds of moderate strength occur between the hydroxyl group and the O atom in the nitro one

Crystal and molecular structure of (2 Z ,5 Z )-3-(2-methoxyphenyl)-2-[(2-methoxyphenyl)imino]-5-(4-nitrobenzylidene)thiazolidin-4-one

International audienceIn the title compound, C24H19N3O5S, the thiazole ring (r.m.s. deviation = 0.012 A) displays a planar geometry and is surrounded by three fragments, two methoxyphenyl and one nitrophenyl. The thiazole ring is almost in the same plane as the nitrophenyl ring, making a dihedral angle of 20.92 (6)degrees. The two methoxyphenyl groups are perpendicular to the thiazole ring [dihedral angles of 79.29 (6) and 71.31 (7)degrees and make a dihedral angle of 68.59 (7)degrees. The molecule exists in an Z,Z conformation with respect to the C=N imine bond. In the crystal, a series of C-H...N, C-H...O and C-H...S hydrogen bonds, augmented by several [pi]-[pi](ring) interactions, produce a three-dimensional architecture of molecules stacked along the b-axis direction. The experimentally derived structure is compered with that calculated theoretically using DFT(B3YLP) methods

Electron Charge Density Distribution from X-ray Diffraction Study of the M-Nitrophenol Compound in the Monoclinic Form

At room temperature, the m-Nitrophenol (m-NPH) appears in two polymorphicstructures: orthorhombic and monoclinic forms. In the present work, we shall focus on themonoclinic form of this compound which has a centrosymmetric structure with the spacegroup P21/n. The molecular dipole moment has been estimated experimentally. Highresolution single crystal diffraction experiment was performed at low temperature withMoKα radiation. The crystal structure was refined using the multipolar model of Hansen andCoppens (1978). The molecular electron charge density distribution is described accurately.The study reveals the nature of inter-molecular interactions including charge transfer andhydrogen bonds. In this crystal, hydrogen bonds of moderate strength occur between thehydroxyl group and the O atom in the nitro one

Theoretical and Experimental Electrostatic Potential around the m-Nitrophenol Molecule

This work concerns a comparison of experimental and theoretical results of the electron charge density distribution and the electrostatic potential around the m-nitrophenol molecule (m-NPH) known for its interesting physical characteristics. The molecular experimental results have been obtained from a high-resolution X-ray diffraction study. Theoretical investigations were performed using the Density Functional Theory at B3LYP level of theory at 6-31G* in the Gaussian program. The multipolar model of Hansen and Coppens was used for the experimental electron charge density distribution around the molecule, while we used the DFT methods for the theoretical calculations. The electron charge density obtained in both methods allowed us to find out different molecular properties such us the electrostatic potential and the dipole moment, which were finally subject to a comparison leading to a good match obtained between both methods. The intramolecular charge transfer has also been confirmed by an HOMO-LUMO analysis

Solvent Effects on Molecular Structure, Vibrational Frequencies, and NLO Properties of N-(2,3-Dichlorophenyl)-2-Nitrobenzene-Sulfonamide: a Density Functional Theory Study

Density functional theory (DFT) calculations have been performed to obtain optimized geometries, vibrational wavenumbers, highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) energies, nonlinear optical (NLO), and thermodynamic properties as well as molecular surfaces for N-(2,3-dichlorophenyl)-2-nitrobenzene-sulfonamide in different solvents. B3LYP level gives similar results for geometric parameters and vibration frequencies in gas phase, water, and ethanol solvents. The most stable structure, which is defined by the highest energy gap between HOMO and LUMO, is obtained in gas phase (a dagger E = 10.7376 eV). Obtained small energy gaps between HOMO and LUMO demonstrate the high-charge mobility in the titled compound. The magnitude of first static hyperpolarizability (beta) parameter increases by the decreasing HOMO-LUMO energy gap. The intensive interactions between bonding and antibonding orbitals of titled compound are responsible for movement of pi-electron cloud from donor to acceptor, i.e., intramolecular charge transfer (ICT), inducing the nonlinear optical properties. So, the beta parameter for title compound is found to be in the range of 5.5255-3.7187 x 10(-30) esu, indicating the considerable NLO character. All of these calculations have been performed in gas phase as well as water and ethanol solvents in order to demonstrate solvent effect on molecular structure, vibration frequencies, NLO properties, etc

A Comparative X-ray Diffraction Study and Ab Initio Calculation on RU60358, a New Pyrethroid

The crystal structure of RU60358, C20H21NO3, has been determined using X-raydiffraction to establish the configuration and stereochemistry of the molecule around theC15-C16 triple bond. The compound crystallises in the orthorhombic space group P212121, a= 7.7575, b = 11.3182, c = 21.3529Ã¥, V = 1874.80Ã¥3 and Z = 4. The structure has beenrefined to a final R = 0.068 for the observed structure factors with I ≥ 3à (I). The refinedstructure was found to be significantly non planar. A comparative study, using the ab initiocalculations of the structure at B3LYP/6-31G** levels of theory, shows good geometricalagreement with the X-ray diffraction data. Standard deviations between the calculated andexperimental bond values have been shown to be 0.01 Ã¥ and 0.5° for bond angles.Vibrational wavenumbers were obtained from a normal mode analysis using the ab initiocalculations