Crystal structure of hexahydro-cis-(1-H,4a-H)-1-p-bromophenyl-1H,3H-pyrido[1,2-c][1,3]oxazine

The crystal and molecular structure of hexahydro-cis-(1-H,4a-H)-1-p-bromophenyl-1H,3H-pyrido[1,2-c][1,3]oxazine, (C₁₄H₁₈BrNO), has been determined from three-dimensional diffractometer data. The space group isP2₁/c; the unit cell has dimensionsa = 10·682(1),b = 21·606(2),c = 5·856(1) Å, = 90·0 ° (at 20 °C) and contains four molecules. The structure has been refined to a residual (R) of 0·056 using least-squares methods on 1240 independent non-zero reflexions.The molecular geometry and conformation of the bicyclic ring is discussed.     

Crystal and molecular structure of 1,4-dichloro-7-methylpyrrolo[3,2-d]pyridazine

Crystals of 1,4-dichloro-7-methylpyrrolo[3,2-d]pyridazine,·C₇H₃N₃Cl₂, are monoclinic:a = 18.7465(9),b = 9.3031(3),c = 9.5363(3) Å, = 104.755(3) °,Z = 8,P2₁/n,D _x = 1.667 g cm^–3, (MoK) = 7.4 cm^–1. The structure was solved by Fourier techniques and refined toR = 0.042 for the observed reflections, and 0.060 for all data measured. The two independent molecules in the asymmetric unit have similar geometry. The packing in the crystal is due to van der Waals' forces and two hydrogen interactions of type N-H N.     

X-ray structures of 1,3-dithiolo[4,5-c]quinoline and 2,3-dihydro-1,4-dithiino[5,6-c]quinoline

The title compound I (C₁₀H₇NS₂) is orthorhombic: Pbca,a=16.223(6),b=15.065(5),c=7.356(4) Å. The conformation of 1,3-dithiol ring is of an envelope-type. A very short intramolecular sulfur-sulfur distance of 2.94 Å was observed. The compoundII (C₁₁H₉NS₂) is monoclinic: P2₁/c,a=5.113(2),b=11.978(4),c=16.444(5) Å, =98.00(5) deg. The conformation of the 1,4-dithiin rings is a half-chair. As compared to other 3,4-quinolinediyl bis-sulfides an elongated intramolecular sulfur-sulfur distance of 3.437(4) Å in dihydrodithiinoquinolineII was observed.Part XXXI in the series of Azinyl Sulfides.     

Imino-Diels-Alder Adducts. Part XIII. Polymorphism in Pyrano [3,2-c] Quinolines

Abstract Crystallization by slow evaporation of methanol solution of 5-(4-nitrophenyl)-3,4,4a5,6,10b-hexahydro-2H-pyrano[3,2-c] quinoline, yields two polymorphs. Rectangle plate-like crystals have a triclinic (P ) structure, with one molecule in the asymmetric unit, a = 8.2299(5) ?, b = 9.7774(6) ?, c = 11.0047(7) ?, α = 65.718(1)°, β = 75.699(1)° and γ = 71.617(1)°, while, long needle-like crystals exhibit a monoclinic (C2/c) crystal structure in which two independent molecules comprise the asymmetric unit, a = 32.285(3) ?, b = 9.4045(7) ?, c = 22.804(2) ? and β = 114.965(1)°. The crystal structures reveal the molecule in both the polymorphs as an endo-Imino-Diels-Alder cycloadduct isomer. The stereochemistry of the pyran ring in both the polymorphs is exo to the quinoline ring formed in the cycloaddition step. The molecules are linked by N–H···O hydrogen bonds into centrosymmetric dimers forming R₂ ²(18) rings in the triclinic form, while they are arranged to form a helical chain in the monoclinic form. Index abstract Crystallization by slow evaporation of methanol solution of 5-(4-nitrophenyl)-3,4,4a5,6,10b-hexahydro-2H-pyrano[3,2-c] quinoline, yields two polymorphs. The crystal structures reveal the molecule in both the polymorphs as an endo-Imino-Diels-Alder cycloadduct isomer. The stereochemistry of the pyran ring in both the polymorphs is exo to the quinoline ring formed in the cycloaddition step. The molecules are linked by N–H···O hydrogen bonds into centrosymmetric dimers forming R₂ ²(18) rings in the triclinic form, while they are arranged to form a helical chain in the monoclinic form. In the present study, we have determined the crystal structures of two polymorphs of pyranoquinoline, I and II.     

Crystal and molecular structure of 2-bromobenzo[b]indeno[1,2-e]pyran

2-bromobenzo[b]indeno[1,2-e]pyran crystallizes in the monoclinic system: space groupP2₁/c,a = 7·508,b = 5·959,c= 26·172 Å, = 92·55 °. The structure has been determined by the heavy-atom method and refined by full-matrix least squares toR = 0·072 for 1027 observed reflections.The molecule is non-planar; the maximum deviations from the best plane occur at both ends of the length of the molecule, which results in distortion of the central portion from the expected geometry. The closest approach of two molecules, those related by a 2₁ axis, is 3·5 Å.     

1,4-Di-[2-phenyl-1-diazenyl]perhydro-1,4-diazepine: X-ray crystal structure

1,4-Di-[2-phenyl-1-diazenyl]perhydro-1,4-diazepine (1) has been synthesized by reaction of benzenediazonium chloride with homopiperazine (perhydro-1,4-diazepine). The crystal structure of 1 has been determined by single crystal X-ray diffraction analysis. The bis-triazene (1) adopts an extended conformation which precludes any close intramolecular interaction of the phenyl rings. The heterocyclic seven-membered ring adopts a chair conformation, with the triazene side chains occupying alternate axial and equatorial positions consistent with cis-geometry. Internal torsion angles of the seven-membered ring have been measured. The crystal packing is determined by short contacts between C=H groups of phenyl rings and nitrogens of triazene moieties and by van der Waals interactions, with no evidence for intermolecular – interactions. This work establishes the structure of the product of diazonium coupling with homopiperazine as 1,4-di[(E)-2-phenyl-1-diazenyl]perhydro-1,4-diazepine. Crystal data: 1 C₁₇H₂₀N₆, monoclinic, space group P2₁/n, a = 9.1838(5) Å, b = 12.1095(6) Å, c = 15.0081(8) Å, = 101.320(2), V = 1636.6(2) Å,³ for Z = 4.     

Synthesis and structure of 1-(2-amino)phenyl-2-phenyl-12H-indolo[3,2-c]carbazole ethylacetate solvate,a new indolocarbazole compound

The structure of a new indolo-carbazole compound, unique in having two indole rings with NH groupstrans-fused to a phenyl ring, has been determined by X-ray crystallography. The crystals are monoclinic, space groupP2₁/n,a=25.548(7),b=8.532(3),c=12.594(4) Å,=93.50(2)°,V _c=2740.1(2) ų,Z=4,D _k=1.240 g cm^–3, (CuK)=1.54178 Å,=5.79 cm^–1,F(000)=1080,R=0.071,R _w=0.080 for 2939 unique significant reflections measured at 298 K. The crystals retain one mole of ethyl acetate per molecule, which shows disorder. Restricted rotation of the phenyl and aminophenyl groups was detected by¹³C nmr. The title Indolo-carbazoles are easily obtained by reaction of 3-bromoindoles with 2,3-biindolyls and show an interesting planar structure which could be investigated for anticancer properties.     

Crystal Structure of 3,4-Dihydro-2-methoxy-2-methyl-4-phenyl-2H,5H-pyrano[3,2-c]chromen-2-one

Crystallography Reports - A new polymorph of 3,4-dihydro-2-methoxy-2-methyl-4-phenyl-2H,5H-pyrano[3,2-c]chromen-2-one (pyranocoumarin) was studied by X-ray diffraction. The crystallographic...     

Crystal structure and spectroscopic study of 2-(p-methoxycarbonylphenyl)-1,3,5,5,7,8,8-heptamethyl-2,4,5,6,7,8-hexahydroindeno[1,2-c]-pyrrole-7-carbonitrile

The crystal structure of the title compound has been determined. The crystals are orthorhombic:Pbnb, (bca setting of Pccn, No 56),a=18.053(8),b=15.532(4),c=16.915(6) Å,V _c =4743(3) ų,Z=8,D _x =1.17 Mg m^–3,=(MoK)=0.71069 Å. The structure was solved by direct methods and refined with 1352 reflections to a finalR value of 0.067. Mass and spectral data (IR, UV,¹H and¹³C NMR) are also reported.     

Crystal structure of a furo-[3,2-g]-[1]-benzopyran-7-one derivative

The crystal structure of 9–(1,1-dimethyl–2-propenyl)-4-hydroxy-7H-Furo-[3,2-g]-benzopyran-7-one has been determined from X-ray diffraction data. The compound crystallizes in the monoclinic space group C2/c with unit cell parameters a = 8.976(3) Å, b = 16.621(2) Å, c = 17.818(2) Å, β = 95.79(2) Å. The gross structure was determined by direct methods and refined to a final value of R = 0.053. The three ring framework of the molecule is nearly planar. The side chain attached at the atomic position C(9) possesses significant foldings and has been found inclined to the ring system of the molecule.     

Structure of 1,2,3,4,9,9a-hexahydro-6,9a-diphenyl-1H-pyrimido[2,1-c][1,4]thiazine

The title compound C₁₈H₂₀N₂S is monoclinic, witha=10.256(2),b=7.470(4),c=21.377(4) Å,=101.52(2)°,z=4 and space groupP2₁/n. The structure was solved by direct methods, and refined by weighted full-matrix least squares. The refinement, based on 1373 reflections withI2.5 (I), converged to a finalR of 0.062 (R _w=0.060). The conformation of the thiazine ring is a distorted half chair, and that of the pyrimidine ring is a distorted chair. All nonhydrogen intermolecular distances are greater than 3.5 Å.     

Crystal structure of 3,3-diphenylnaphtho [1, 2-c] furan-1 (3H)-one

The crystal structure of 3, 3-diphenylnaphtho[1, 2-c]furan-1(3H)-one 2 was determined by X-ray diffraction analysis. It possesses P2₁2₁2₁ (#19) space group symmetry, with a = 11.922(2), b = 17.142(4), c = 8.429(2) Å, and D _calc = 1.297 mg/m³ for Z = 4.     

Structural and conformational studies of derivatives of 2,4,8-trihydroxy-5-oxo-10-methylbenzo[1,2-c]chromene (alternariol). II: Crystal and molecular structure of (±)-1-methoxycarbonyl-1-hydroxy-2-oxa-3,4-dioxo-7-methoxy-9-methylcyclopenteno [3,4-c]chromene

The crystal and molecular structure of (±)-1-methoxycarbonyl-1-hydroxy-2-oxa-3,4-dioxo-7-methoxy-9-methylcyclopenteno[3,4-c] chromene (Altox, II) has been determined by x-ray crystallographic methods. The crystals are monoclinic:a= 10.748,b = 9.644,c= 13.845 Å, = 104.58 °,Z = 4,P2₁/c. The structure was solved by direct methods and refined by full-matrix least-squares on 1158 symmetry-independent ¦F ₀¦-data toR = 6.9%. The molecules are linked by hydrogen bonds (O...O = 2.74 Å), forming a chain-like structure.     

Crystal structure of hexahydro-cis-(1-H,4a-H)-1-p-bromophenyl-1H,3H-pyrido[1,2-c][1,3]thiazine

The crystal and molecular structure of hexahydro-cis-(1-H,4_a-H)-1-p-bromophenyl-1H,3H-pyrido[1,2-c][1,3]thiazine, (C₁₄H₁₈BrNS), has been determined from three-dimensional diffractometer data. The space group isI4₁/cd and the unit cell has dimensionsa = 22·906(4),b = 22·906(4),c = 10·646(2) Å withZ = 16. The structure has been refined to a residual of 0·065 using least-squares methods on 1235 independent non-zero reflexions.The molecular geometry and conformation of the bicyclic ring is discussed and compared with the related oxazine compound.     

1H,4H-1,4-Diphenylpyridazino[1,2-α]pyridazine-6, 9-dione

Crystals of C₂₀H₁₆N₂O₂ are orthorombic:P2₁2₁2₁,a = 28.1364(21),b = 7.6474(2),c = 7.5376(2) Å,Z = 4, = 6.4 cm^–1 (CuK radiation), andM = 316.36. The structure has been solved by direct methods and refined by two-block least-squares toR = R _w = 0.042. The conformation of ringB is a distorted envelope at N(10), and the phenyl rings have acis configuration with respect to the pyridazine ring. Thermal motion of the molecule has been analyzed in terms of the rigid-body TLS model.On leave from Departamento de Fisica, Facultad de Ciencias Exactas, U.N.L.P., calle 115 esq. 49, La Plata, Buenos Aires, Argentina.