Crystal structure of (Z)-1-(sec-butyl)-3-(4-dimethylaminophenyl)-2-(1H-1,2,4-triazol-1-yl)propen-2-one

The crystal structure of the title compound is determined by X-ray diffraction studies. The structure is solved by the direct method. The experimental data are obtained on a DAR-UMB diffractometer by the θ-θ/2θ scan technique using MoK _α radiation. The crystal is monoclinic, a = 17.913(3) Å, b = 17.239(3) Å, c = 5.501(5) Å, γ = 74.4(3)°, space group P2₁/a, Z = 4 for C₁₇H₂₂N₄O, and ρ_calcd = 1.211 g/cm³. The molecule consists of the phenyl and triazole rings and the dimethylamino, carbonyl, and isopropyl groups attached to the rings. The dihedral angle between the rings is 67.4°. The carbonyl oxygen atom and the triazole ring are in the trans position relative to each other. The N-C-C-O torsion angle is 172.8°. The molecule is in the Z isomeric form.     

Crystal and molecular structure of (E)-21-Methoxycarbonyl-19-nor-pregna-4,8(14),20-trien-3-one

The crystal and molecular structure of the title compound has been determined by X-ray diffraction techniques. It crystallizes in the orthorhombic space group P 2₁2₁2₁ with cell parameters a = 12.662 Å, b = 17.995 Å, c = 8.433 Å. The structure was solved by direct methods using MULTAN-78 and refined by least-squares calculations to the conventional R = 0.061. The ring conformations of the steroid skeleton and the 17β-side chain conformation are discussed in detail.     

Crystal structures of two isomeric oximes. (EE)-2-methyl-3-phenyl-3-thiocyanatopropenaldoxime and (Z)-5-methyl-6-phenyl-1,3-thiazin-2-one oxime

The crystal structure of two isomeric oximes, C₁₁N₁₀N₂OS have been studied by X-ray diffraction. The open-chain thiocyanato derivative is somewhat'less dense and crystallizes with the orthorhombic space group Pbcn;a,b,c=18.718(1), 10.601(3), 11.528(1) Å,Z=8. The heterocyclic isomer occurs as pseudo-orthorhombic (Cmma)twinned crystals of space group P2₁/n, a, b, c, =12.11(1), 7.46(1), 12.12(1) Å, 100.09(1)^o,Z=4. Twinning occurs as a result of the near-equality of the monoclinica andc cell constants.     

Crystal and molecular structure of (Z)-2-(1,3-benzothiazol-2-yl)-2-(6,7,8,9-tetrahydro-5H-benzocyclohepten-5-ylidene)ethanonitrile

The title compound C₂₀H₁₆N₂S is crystallized in the monoclinic space groupP2₁/c with cell parametersa=10.663(4),b=17.585(9),c=9.418(5)Å,=115.23°(4),V=1598(3)ų,Z=4. The structure was refined by full-matrix least-squares methods using X-ray data set collected at room temperature. A finalR _F =0.033 andR _w =0.048 for 2225 unique reflections withI> 3(I) and 272 variables was obtained. The X-ray crystallographic study establishes theZ stereochemistry of the title compound.     

The Synthesis and Crystal Determination of 3-Hydroxy-4-(4-methoxyphenyl)-5-(2-nitrophenyl)furan-2(5H)-one

Abstract  

The title compound, C₁₇H₁₃NO₆, was synthesized and structurally characterized by elemental analysis, MS, ¹H NMR and single crystal X-ray diffraction. It crystallizes in monoclinic system space group C 2/c with a = 27.981(6) ?, b = 12.996(3) ?, c = 8.0900(16) ?, β = 91.06(3)°, V = 2941.4(10) ?³, Z = 8, R ₁ = 0.0675, wR ₂ = 0.1626, and T = 298(2) K. The X-ray structure determination revealed that the center furanone ring is nearly coplanar with p-methoxybenzene ring and forms a dihedral angle of 87.2(1)° with the nitrobenzene ring. O–H···O Intermolecular hydrogen bonds link pairs of molecules into centrosymmetric dimers, making a graph set motif of R ₂²(10). The dimers are further assembled into a chain of edge-fused R ₄⁴(34) rings running along the [001] direction. The final three-dimensional supramolecular architecture is stabilized by weak π–π interactions.     

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.     

Crystal and molecular structure of (E)-2-t-butyl-3(3′-t-butyldimethylsiloxy)propyl-2-cyanocyclobutanone

The title compound crystallizes in the monoclinic space group P2₁/a, witha+12.906(9).b+11.604(2).c+14.631(9) Å, β=108.70(3)° andZ+4. The structure was solved by direct methods from diffractometer data and refined to a finalR value of 0.057 for 2020 independent reflections. The structure analysis confirms the cis disposition of the bulky substituents and indicates a puckered four-membered ring with a dihedral angle of 18.5° as expected for a non-centrosymmetrically substituted cyclobutanone.     

Crystal structure of 3-phenyl-7-bromoisoxazolo[4,5-d]pyridazin-4(5H)-one

The crystal and molecular structure of 3-phenyl-7-bromoisoxazolo[4,5-d]-pyridazin-4(5H-one, C₁₁H₆BrN₃O₂, has been determined from two- and three-dimensional X-ray data and refined by Fourier and least-squares methods toR = 0·101 for 1187 observed reflexions. Crystals of 3-phenyl-7-bromoisoxazolo-[4, 5-d]pyridazin-4(5H)-one are monoclinic:a = 7·67,b = 6·84,c = 20·52 Å, = 91·5 °,Z = 4, space groupP2₁/c. The benzene ring makes an angle of 4·5 ° with the plane of the isoxazole ring, and the other part of the molecule is slightly non-planar. The bond distances and angles compare well with those of other similar molecules. Two N-H...O hydrogen bonds join the two molecules related by a centre of symmetry. Close molecular packing is found in layers parallel to (100).     

Crystal and molecular structure of OC(CoC5H5)3(CF3CCCF3)

The structure of the title compound has been confirmed by an X-ray diffraction analysis, and refined by full-matrix least squares. The crystals are mono-clinic:a=9.171(3),b=25.176(15)c=9.192(3) Å,=117.08(3)°,Z=4,D _x =1.976g cm^–3,=2.66mm^¯1, space groupP2₁/n (No. 14). The finalR value is 5.7%. Interatomic distances and bond angles are compared with those reported in related molecules.The preferred name of this compound according to the IUPAC rules is ₃-[11–2-bis(trifluoromethyl)vinylene]- ₃-carbonyl-tris (-cyclopentadienyl)-triangulo-tricobalt.     

Crystal structure of 3β-acetoxy-pregna-5,16-dien-20-one (16 DPA)

The title compound, 3β-acetoxy-pregna-5,16-dien-20-one, C₂₃H₃₂O₃, has been synthesized by acetylation followed by oxidation of diosgenin and its crystal structure has been solved from single crystal X-ray diffraction data. The compound crystallizes into orthorhombic space group P2₁2₁2₁ with unit cell parameters: a = 6.031(4) ?, b = 12.481(2) ?, c = 27.162(5) ?, Z = 4. The crystal structure has been refined to R = 0.0597 for 1291 observed reflections. Rings A and C of the compound are in chair conformation whereas ring B is in half-chair conformation. Ring D is in envelop conformation. The A/B ring junction is quasi-trans, while ring systems B/C and C/D are trans fused about the C8–C9 and C13–C14 bonds, respectively. The steroid nucleus has a small twist, as shown by the C19–C10⋅C13–C18 pseudo-torsion angle of 9.5°. The crystal packing is determined by a pair of weak C–H⋅O hydrogen bonds in addition to van der Waals interactions.     

Crystal and molecular structure of (Z)-5,6-dihydro-8(7H)quinolinone thiosemicarbazone

The crystal structure of (Z)-5,6-dihydro-8(7H)quinolinone thiosemicarbazone has been determined by X-ray diffraction techniques in order to confirm the identity of this analog of the antineoplastic agent 2-formylpyridine thiosemicarbazone and to determine the nature of the hydrogen bonding in the solid state. The crystals are pale yellow, space groupP2₁/n, witha = 7.682(3),b = 10.168(8),c = 14.795(5) Å, = 103.11(4) °, andZ = 4. The structure was solved by direct methods and refined to a finalR value of 0.017. The molecule is quite planar, with the obvious exception of the central saturated carbon, and this, along with a short C-C bond at the point of attachment of the side chain, appears to be due to an interaction with the pyridyl ring. The molecules are arranged in pairs held together by mutual intermolecular SN hydrogen bonds. There is also an extensive system of intramolecular NN hydrogen bonds.     

Molecular structure of (±)-5-benzylamino-endo-tricylo[5.2.1.02,6]dec-4-en-3-one

The crystal and molecular structure of (±)-5-benzylamino-endo-tricyclo[5.2.1.0^2.6]dec-4-en-3-one is described. The X-ray analysis revealed that the reduction of the norbornene double bond is an important process in the irradiation of the used enaminones. The structure was solved by direct methods and refined by least squares methods toR ₁=0.0468 for 2070 reflections (withI>2σ(I). Crystal data: C₁₇H₁₉NO, Orthorhombic, space groupPbcn, a=40.695 (1),b=6.6928 (1),c=10.2378(4)Å,V=2788.44(14)ų,Z=8.     

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.