Crystal and molecular structure of 2′,4′-dimethoxyflavone

C₁₇H₁₄O₄,M _r =282.3, triclinic,P-1,a=8.469(3),b=8.516(2),c=20.425(8)Å,=84.95(3),=81.98(3), =70.47(2)°,V=1373(13)ų,Z=4,D _x =1.365 g cm^–3, (MoK )=0.71069 Å,=0.91 cm^–1,F(000)=592,T=294K,R=0.038 for 3577 observed reflections (F>3 (F)). The asymmetric unit is composed of two molecules. These two molecules, which are in planar conformations, differ in 4-methoxyl group orientation. Short intramolecular contacts are found between the -benzopyran portion and the dimethoxyphenyl ring.     

Crystal and molecular structure of 4′-hexyloxyphenyl 4-pentylbenzoate

The molecular and crystal structure of 4??-hexyloxyphenyl 4-pentylbenzoate, C₆H₁₃O-C₆H₄-COO-C₆H₄-C₅H₁₁, which is a liquid-crystal compound, was determined by X-ray diffraction. This compound forms a nematic phase upon melting. The crystal contains three crystallographically independent molecules. In one of them, the alkyl chain is disordered. This is indicative of the looseness of the crystal packing in the aliphatic region. The crystal structure is stabilized by the following two types of weak directional interactions: hydrogen bonds with the participation of the terminal O atom of the ester group and the C-H group of one of the benzene rings and C-H????-system interactions. Only one of the three independent molecules is involved in the latter type of interactions. Hence, the structurization of the mesophase is most likely determined by hydrogen bonding.     

Crystal structure of a nucleoside analog: 2′,3′-dideoxy-3′-fluoro-5-bromocytidine

The title compound crystallizes in the orthorhombic space groupP2₁2₁2₁ witha=5.084(1),b=14.322(3),c=16.065(2)Å,Z=4. The structure was solved by the heavy atom method and refined by full-matrix least-squares calculations to a finalR value of 0.033 for 1106 unique observed reflections. The N-glycosidic torsion anglex has a value of –153.7(4)°, in the anti-range. The sugar pucker is²T₃ withP=175(1)° and=30(1)°. The C4-C5 conformation is + sc with =46.7(7)°. The structure is stabilized by N-HN, N-HO and O-HO hydrogen bonds and C-HO close contacts.     

Crystal and molecular structure of 1,1′-ferrocene-dicarbaldehyde

The crystal and molecular structure of 1,1-ferrocene-dicarbaldehyde 1 is reported. Crystal data for 1: monoclinic, space group P2₁/n, a = 5.876(1), b = 11.349(1), c = 29.460(3) Å, = 95.067(2)°, V = 1956.9(3) ų, and D _c = 1.64 g/cm³, for Z = 8. The complex crystallizes such that two molecules are located in the asymmetric unit in which the complexes display different degrees of twisting of the cyclopentadienyl (Cp) rings and formyl substituents about the Cp—Fe—Cp and Cp—COH axes, respectively. The molecule self-assembles in the solid state to form a 2D layered structure held together by - interactions and C—H···O hydrogen bonds.     

Crystal structure of a nucleoside analog, 2′,3′-dideoxy-3′-azido-5-chlorocytidine

The title compound, l-(2,3-dideoxy-3-azido--D-erythro pentofuranos-1-yl)-5-chlorocytosine, crystallizes in the orthorhombic space groupP2₁2₁2₁ witha=5.840(1),b=13.780(1),c=15.396(2)Å,Z=4. The structure was solved by direct methods and refined by full-matrix least-squares calculations to a finalR value of 0.033 for 1688 unique observed reflections. The N-glycosidic torsion angle has a value of –160.8(1)°, in the and range. The sugar pucker is ₂ ³ T withP=180(1)° and=34(1)°. The C4–C5 conformation is +sc with =50.8(2)°. The azido group is nonlinear and oriented trans to the C3–C4 bond. The molecular packing in the crystalline space is stabilized by N-HN, N-HO, O-HO hydrogen bonds and C-HO close contacts.     

Crystal and molecular structure of 2-(2′-chloro-5′-nitrostyryl)benzoselenazole

The title compound C₁₅H₉ClN₂O₂Se (nsbse) is orthorhombic, witha=6.823(2),b=7.860(2),c=26.349(5) Å,Z=4,D _x =1.709,(MoK)=28.3 cm^–1,F(000)=720,T=298K in space groupP2₁2₁2₁. The structure was solved by heavy atom and Fourier methods and refined toR=0.045 for 1095 unique observed reflections. The molecule is almost planar, with a dihedral angle of 4.8(2)° between the benzoselenazole and phenyl rings. The C-Se-C angle in the selenazole ring is very small, 84.6(4)°, while the C-N-C angle in that ring is 113.7(7)°.     

X-ray structure and NMR assignment of 4-methoxy-4′-methylthio-3,3′-diquinolinyl sulfidea

The title compound (C₂₀H₁₆N₂OS₂) is monoclinic, witha=7.786(3).,b=13.252(3),c=17.162(4) Å, =99.16(3)° and space groupP2₁/n. Two quinoline moieties are nearly perpendicular to each other (112.9(2)°). Both methoxy and methylthio groups are trans-orientated with the respect to the C(3)–S(1)–C(13) plane. Two pairs of the heteroatoms in ortho-positions are in very close contact. The conformation of the molecule explains an unusual¹H NMR spectrum     

Synthesis and X-ray structure of 5′-methoxy-2,4,6-trimethyl-2′-nitrosobiphenyl

The synthesis and X-ray crystal structure of 5-methoxy-2,4,6-trimethyl-2-nitrosobiphenyl is reported. The compound (C₁₆H₁₇NO₂) is monoclinic, with a = 11.080(4), b = 16.899(6), c = 15.410(5) Å, = 108.329(5)°, and space group P2₁/n. There are two independent molecules within the crystal. In each of these molecules the two phenyl rings are mutually orthogonal, with interplanar dihedral angles of 85.09 and 89.43° respectively. The nitroso substituents are essentially coplanar with the phenyl ring, with torsional angles of only 3.5 and 2.2°, respectively, while the methoxy groups make angles of 5.2 and 10.0°, respectively, with the phenyl ring.     

Crystal and molecular structure of 1,4-S,S′-bis-isothiosemicarbazidebutane dihydrobromide

The synthesis and crystal structure of 1,4-S,S-isothiosemicarbazidebutane dihydrobromide have been presented. The crystals are monoclinic:P2₁/n, a=7.9910(10),b=10.979(2),c=8.9240(10)Å, =111.450(10)°,Z=2, room temp. The structure was solved by direct methods. and refined to R=0.0297 for 846 reflections. The title compound consists of the centrosymmetric [C₆H₁₈N₆S₂]²⁺ dication and two Br^– anions. Intramolecular N–H...N and intermolecular N–H...Br hydrogen bonds stabilizetrans conformation of the thiosemicarbazide moiety.     

X-ray crystal and molecular structure of 2,3-dideoxy-4-thio-d-arabino-heptonic acid 1,4-lactone: a key intermediate for syntheses of 2′, 3′-dideoxy-4′-thio-l-nucleosides

The structure of 2,3-dideoxy-4-thio-d-arabino-heptonic acid 1,4-lactone has been determined by X-ray diffraction. Crystals of the compound are orthorhombic, space groupP2₁2₁2₁, with cell dimensionsa=11.555(5),b=10.451(5),c=9.604(5) Å, andZ=4. The diffraction experiment has allowed to assign the absolute configuration (4R, 5R, 6R) to the chiral centers of the molecule.     

Crystal structure of 2,5-cyclohexadien-4-one-spiro-3′-(2′-methylthio-5′,5′-dimethyl-1′-pyrroline)

The crystal structure of the pyrrole derivative 2,5-cyclohexadien-4-one-spiro-3′-(2′-methylthio-5′,5′-dimethyl-1′-pyrroline) is determined by X-ray diffraction. Two independent molecules have similar structures and close geometric parameters but differ in configuration of the pyrrole ring and orientation of the thiomethyl group with respect to the pyrrole ring.     

Crystal and molecular structure of CI Solvent Yellow 18, 4-(2′,4′-dimethyl phenyl hydrazono)-5-methyl-2-phenyl-3H-pyrazol-3-one

The crystal structure of CI Solvent Yellow 18, C₁₈H₁₈N₄O, has been determined by single crystal X-ray diffraction techniques. It crystallizes in the monoclinic system witha=7.480(2) Å,b=19.184(3) Å,c=11.260(1) Å,=98.00(3)°, space groupP2₁/n andZ=4. The structure has been solved by direct methods, and least-squares refinement has been completed on three-dimensional data (2310 reflections, CuK radiation). The hydrogen atoms have been found, but only their positional parameters refined. Final residual 0.085 (all positive intensity data). The molecule exists as the hydrazone tautomer and intramolecular hydrogen bonding keep the molecule approximately planar. The molecules are packed in layers parallel to the (¯202) plane and in columns parallel tob. Alternate molecules within the columns are in antiparallel. The molecules are linked by van der Waals' forces.     

Crystal structure of a nucleoside analogue, 2′,3′-dideoxy-3′-fluoro-5-chlorocytidine

The title compound, 1-(2,3-dideoxy-3-fluoro--d-erythro pentofuranos-1-yl)-5-chlorocytosine, crystallises in the orthorhombic space groupP2₁2₁2₁ witha=5.142(1),b=14.177(2),c=15.721(2) Å,Z=4. The crystal structure was solved by the heavy atom method and refined by full-matrix least-squares method to a finalR value of 0.031 for 1629 unique observed reflections. The N-glycosidic torsion angle is –156.1(2)° and the sugar moiety is anti to the cytosine base. The sugar pucker is ₂ ³ T withP=178.2(1)° and=31(1)°. The atom 05 is in a +sc conformation with respect to the furanose ring. The molecular packing in the crystal is stabilized by N-HN, N-HO, O-HO hydrogen bonds and C-HO close contacts.     

Synthesis and crystal structure of 1-(1′,3′-dimethyl-5′-chloropyrazol-4′-carbonyl′-3-(2′-chlorophenyl)-5-amino-4-cyanopyrazole

The title compound 1-(1,3-dimethyl-5-chloropyrazol-4-carbonyl)-3-(2-chlorophenyl)-5-amino-4-cyanopyrazole (C₁₆H₁₂Cl₂N₆O) has been synthesized and characterized by X-ray diffraction: Triclinic, space group P1, with a = 8.6712(8) Å, b = 9.5091(10) Å, c = 11.2170(11) Å = 71.531(2)°, = 84.683(2)°, = 74.099(2)° Z = 2; V = 843.7(14) ų. C(10), O(1), C(11), and N(2) atoms are coplanar with the average deviation of 0.0071 Å, which form 11.03° and 43.93° dihedral angles with pyrazole planes (I) and (II), respectively.     

Crystal structure of 2,4′-biflavonoid

The X-ray crystal structure of 2,4′-biflavonoid has been determined. Colorless regular prism shaped crystals of C₃₀H₂₂O₄ crystallize in the space group $P\bar 1$ with cell dimensionsa=11.574(1) Å,b=12.235(1) Å,c=17.428(1) Å, α=108.46(3)^o, β=80.08(1)^o, γ=103.34(2)^o,V=2264.7(4) ų, andZ=4.     

Crystal and molecular structure ofN,N′-diphenylpiperazine N,N′-dioxide octahydrate

The title compound isN,N-DiphenylpiperazineN,N-dioxide octahydrate, C₁₆H₃₄N₂O₁₀:M _r=414.46, orthorhombic, space groupPnma (No. 62),a=12.327(2),b=9.804(1),c=17.443(4) Å,V _c=2108.1(5) ų,Z=4. The structure was solved by the direct method and refined toR=0.056 for 3032 observed MoK reflections. In theN,N-dioxide molecule, all atoms except those of the methylene groups lie on a crystallographic mirror plane. The piperazine ring takes the chair form, with two N-O bonds oriented axially in atrans configuration. The crystal structure is characterized by strong hydrogen bonding between the water molecules, as well as between theN-oxide groups and water molecules, giving rise to a three-dimensional network structure composed of edge-sharing four-membered, five-membered, six-membered, and fourteen-membered rings.     

The crystal structure of the molecular complex of 2′,6′-dimethoxyflavone with picric acid: Alternating π-stacking and hydrogen-bonding interactions

The title complex is monoclinic with a = 15.100(5), b = 7.624(3), c = 39.997(15) Å, = 99.49(4)°, Z = 8, and space group P2₁/c. There are two geometrically independent, hydrogen-bonded pairs of molecules in the asymmetric part of the structure. Picric acid and 2,6-dimethoxyflavone are held together by hydrogen bonding between the hydrogen of the phenol group and the oxygen of the carbonyl. Additionnally, this hydrogen forms an intramolecular hydrogen bond with the O atom of an ortho-nitro group. Moreover, a stacking interaction is observed between the -benzopyrone portion of the flavone and picric acid.     

Crystal and molecular structure of (±)-1-phenyl-2-amino-1-propanol,C9H13NO

The crystal structure of (±)-phenylpropanolamine has been determined by single-crystal X-ray diffraction methods. The structure was solved by direct methods and refined by least-squares toR=0.055 andR _w=0.045 for 2000 reflections (I2 (I)). The molecule was found to adoptgauche geometry. Inter- and intramolecular N-HO and O-HN hydrogen bonds were observed in the crystal structure.     

Crystal and molecular structure of 2,6-dimethyl-3-acetyl-5-carbomethoxy-4- (4′-methoxyphenyl)-1,4-dihydropyridine

2,6-Dimethyl-3-acetyl-5-carbomethoxy-4-(4-methoxyphenyl)-1,4-dihydropyridine has been synthesized and characterized by X-ray diffraction analysis. The compound crystallizes in the monoclinic space group P2 ₁/c with cell parameters a=16.085(2) Å, b= 12.332(3) Å, c= 8.479(4) Å, = 99.23(8)°, Z=4. The structure exhibits both intra and intermolecular hydrogen bonds. The structure adopts a flat boat conformation in the dihydropyridine ring.