Crystal Structure of 3-Hydroxy-3′,4′-Methylenedioxy Flavone-6-Carboxylic Acid Dimethylformamide Solvate

Abstract  

The optically pure 3-hydroxy-3′,4′-methylenedioxy flavone-6-carboxylic acid was obtained through the chalcone route. The structure of 3-hydroxy-3′,4′-methylenedioxy flavone-6-carboxylic acid was first elucidated by single crystal X-ray analysis: triclinic, space group, triclinic (P-1) with a = 8.1379(13) ?, b = 8.9831(14) ?, c = 13.198(2) ?, α = 88.413(2)°, β = 74.908(2)°, γ = 72.987(2)°. V = 889.5(2) ?³, Z = 2. The structure was solved by direct methods and refined to a final R = 0.0413 for 1630 reflections with I > 2σ(I). The crystal structure is stabilized by O–H···O and C–H···O hydrogen bondings and π–π stacking interactions.     

Synthesis and Characterization of Two Pb(II) Complexes of 2,2′-dihydroxy,Dimethoxy-1,1′-binaphthyl-3,3′-dicarboxylic Acid

Two new complexes {[Pb(L¹)(DMSO)₂(H₂O)]·DMF}_n (1, L¹ = 2,2′-dihydroxy-l,l′-dinaphthyl-3,3′-dicarboxylate) and {[Pb(L²)(DMS O)·DMSO}_n (2, L² = 2,2′-dimethoxy-l,l′-dinaphthyl-3,3′-dicarboxylate) have been synthesized under mild conditions and structurally characterized. Crystal structural analysis reveals that complex 1 adopts a 1D infinite chain structure which forms 2D sheet by hydrogen bonds interactions. Complex 2 possesses a 2D sheet structure, which was further assembled into a 3D supramolecular network through the π-π weak interactions. IR spectra indicates the carboxyl group coordinates with the Pb²⁺ ion. TGA shows that complex 2 is highly thermally stable up to 120°C.     

Hydrogen-Bonded Molecular Ladders and Interlaced Networks in Complexes Built of V-Shaped Molecules 4,4′-Isopropylidenediphenol or 4,4′-Oxydibenzoic Acid with 4,4′-Bipyridine

Abstract  

The title compounds, C₁₀H₈N₂·C₁₅H₁₆O₂ (1) and C₁₀H₈N₂·C₁₄H₁₀O₅ (2), were synthesized by 4,4′-bipyridyl and two similar V-shaped molecules. The two complexes both crystallized in the same space group P2₁/n with the crystal cell parameters: a = 16.0536(3) ?, b = 6.42730(1) ?, c = 21.2717(4) ?, β = 102.330°, V = 2144.21(7) ?³, Z = 4 in compound 1 and a = 7.45020(10) ?, b = 10.0784(2) ?, c = 26.9430(5) ?, β = 92.1140(10)°, V = 2021.67(6) ?³, Z = 4 in compound 2. Compound 1 forms regular molecular chains containing alternative 4,4′-bipyridyl and 4,4′-isopropylidenediphenol units; the molecular components are linked by two types of O–H···N hydrogen bonds. Additionally, every two neighboring chains are connected to be a ladder structure by means of weak C–H···O interactions. In compound 2, 4,4′-bipyridyl and 4,4′-oxydibenzoic acid first construct one-dimensional architecture by strong O–H···N hydrogen bonds, which are similar with the interactions in compound 1. Secondly, two types of weak C–H···O contacts formed between 4,4′-bipyridyl and the acid link one-dimensional chains to be interlaced three-dimensional hydrogen-bonded networks.     

X-ray structure of 4-chloro-3′-methylthio-3,4′-diquinolinyl sulfide

The title compound crystallizes in a monoclinic space groupP2₁/n witha=9.524(3),b=6.782(2),c=26.217(6) Å, =92.52(4)°. The values of the Cl...S and S...S distances are well below the sum of the van der Waals radii of the heteroatoms. Also, the Cl–C–C(S) and (Cl)C–C–S bond angles are below the standard 120°. This indicates a attractive interaction between both pairs ofortho-situated heteroatoms.Part XXXVIII in the Series of Azinyl Sulfides.     

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.     

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.     

A structural investigation of ethyl 3′-methyl-6-methoxy-5′-oxo-1,2-cyclopent-3′-enonaphthalene-4′-acetate,C19H18O4

The crystal and molecular structure of the title compound has been determined from X-ray diffraction data using radiation. The compound crystallizes in the triclinic space group witha=8.351(1),b=9.348(2),c=10.736(2) Å,=91.19(2),=90.07(2), =110.18(1)°, andZ=2. The structure was solved by direct methods and a full-matrix least-squares refinement converged to a finalR=0.057 for 2522 unique reflections with I3(I). The cyclopentenonaphthalene ring system is planar (mean deviation, 0.028 Å). The molecules are held together by van der Waals forces. Averaged C-O bond lengths are: C(sp²)-O=1.357(18); C(sp³)-O=1.448(12); and C=O=1.210(14) Å.     

Structure of 2,2′-anhydro-3′-O-acetyl-2′thio-1-β-D-arabinofuranosylcytosine hydrochloride1

2,2-Anhydro-3-O-acetyl-2-thio-1--D-arabinofuranosylcytosine hydrochloride crystallizes in space group P2₁2₁2₁ witha=10.373(1),b=14.517(2),c=9.496(1) Å. Reflections were measured on a diffractometer and the structure was solved by direct methods. Least-squares refinement converged atR=0.056 andR _w =0.063. The study of this crystal structure showed that the alterations in the geometry of 2,2-anhydro-1--D-arabinofuranosylcytosine when the bridge oxygen is replaced by sulfur are localized in the region of the fused ring. The angle at the bridge atom decreases to nearly 90°, with concomitant enlargements of about 5°–7° in the angles opposite to the bridge atom. Angle C(1)-N(1)-C(6) decreases by 4°. Also, the amount of double bond character in the bond formed by C(2) and the bridge atom decreases. A survey of the conformational features of S,2-cyclonucleosides and comparison with O,2-cyclonucleosidcs showed that their preferred conformations are the same. However, S,2-cyclonucleosides exhibit a wider range of P and values. This correlates with a greater ease of the sulfur containing five-membered ring to pucker as compared to the oxygen-cyclo ring.This paper is part of the authors' dissertation (Vitali, 1986).     

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.     

Three-dimensional structure of thymidine phosphorylase from E. coli in complex with 3′-azido-2′-fluoro-2′,3′-dideoxyuridine

The three-dimensional structures of thymidine phosphorylase from E. coli containing the bound sulfate ion in the phosphate-binding site and of the complex of thymidine phosphorylase with sulfate in the phosphate-binding site and the inhibitor 3′-azido-2′-fluoro-2′,3′-dideoxyuridine (N₃F-ddU) in the nucleoside-binding site were determined at 1.55 and 1.50 Å resolution, respectively. The amino-acid residues involved in the ligand binding and the hydrogen-bond network in the active site occupied by a large number of bound water molecules are described. A comparison of the structure of thymidine phosphorylase in complex with N₃F-ddU with the structure of pyrimidine nucleoside phosphorylase from St. Aureus in complex with the natural substrate thymidine (PDB_ID: 3H5Q) shows that the substrate and the inhibitor in the nucleoside-binding pocket have different orientations. It is suggested that the position of N₃F-ddU can be influenced by the presence of the azido group, which prefers a hydrophobic environment. In both structures, the active sites of the subunits are in the open conformation.     

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 1-benzyl-5-bromo-2-oxoindol-3-spiro-2′-(4′-benzoyl-1′-methylpyrrolidin)-3′-spiro-3′′-(1′′-methyl-2′′-oxoindole), C34H28N3O3Br

The title compound crystallizes in space group P-1, with a = 10.574(4) Å, b = 11.262(1) Å, c = 12.536(8) Å, = 90.08(3)°, = 103.63(3)°, = 103.35(2)°. Owing to the centric space group, C3, C3, and C4 chiral centers are either [R, S, S] or [S, R, R].     

Synthesis and Crystal Structure of Nickel(II) Complex with 2,2′-Biimidazole and 4-Aminobenzoic Acid

Abstract  The Ni(II) complex, [Ni(H₂biim)₂(PABA)₂]Cl₂·2H₂O, H₂biim being 2,2′-biimidazole, PABA being 4-aminobenzoic acid has been synthesized and the crystal structure determined using X-ray crystallography. The complex crystallizes in triclinic system, space group P − 1 with unit cell parameters a = 8.3920(9) ?, b = 9.8436(11) ?, c = 9.8874(11) ?, α = 94.862(2)°, β = 109.142(2)°, γ = 90.992(2)°, V = 767.95(15) ?³ and Z = 1. The molecules of the complex in the crystal assemble by way of N–H⋯Cl, O–H⋯Cl, O–H⋯O hydrogen bonds as well as π–π stacking interactions to provide a two-dimensional supramolecular structure. Index Abstract  Synthesis and Crystal Structure of Nickel(II) Complex with 2,2′-Biimidazole and 4-Aminobenzoic Acid Yanping Li and Pin Yang* The molecules of the title complex [Ni(H₂biim)₂(PABA)₂]Cl₂·2H₂O in the crystal assemble by way of N–H⋯Cl, O–H⋯Cl, O–H⋯O hydrogen bonds as well as π–π stacking interactions to provide a two-dimensional supramolecular structure.      

Resolution of 1,1′-Binaphthyl-2,2′-Dicarboxylic Acid with Quinine: Structure of the Intermediate (<Emphasis Type="Italic">S</Emphasis>)-1,1′-Binaphthyl-2,2′-Dicarboxylate Dihydrate Diastereomeric Salt

Abstract  

Racemic 1,1′-binaphthyl-2,2′-dicarboxylic acid (BNDA) was resolved using quinine as the resolving agent. The structure of the resultant quininium (S)-1,1′-binaphthyl-2,2′-dicarboxylate dihydrate salt (1) was elucidated. The asymmetric unit contained one 1,1′-binaphthyl-2,2′-dicarboxylate anion, two quininium cations and two water molecules. The structure was solved successfully in the orthorhombic space group P2₁2₁2₁ with unit cell dimensions: a = 11.100(2) ?, b = 16.572(3) ?, c = 28.726(6) ?.     

Ground state structures of molecules “prepared” for phototautomerization: 2,2′-bipyridyl-3,3′-diol and 2,2′-bipyridyl-3-ol

The crystal structures of two molecules undergoing fast intramolecular excited state proton transfer (2,2-bipyridyl-3,3-diol, BP(OH)₂, and 2,2-bipyridyl-3-ol, BP(OH)) are reported and compared with the results ofab initio and molecular mechanics calculations. Strong intramolecular hydrogen bonding is observed in both cases. The pyridyl rings are coplanar in BP(OH)₂, whereas in BP(OH) they form an angle of 3.7°.Dedicated to Prof. R. Zahradnik on the occasion of his birthday.     

PL Quenching of Poly(3-hexylthiophene) by 2,2′,7,7′-Tetradiphenylamino-9,9′-Bifluorenylidene

2,2′,7,7′-Tetradiphenylamino-9,9′-bifluorenylidene, TDPABF, was synthesized by reductive dimerization using Lawesson's reagent. It is soluble in common organic solvents such as dichloromethane, chloroform, and 1,2-dichlorobenzene. Its synthesis was confirmed by ¹H-, ¹³C- NMR, MALDI-TOF, and FT-IR spectroscopy. Its HOMO and LUMO energy levels were –5.33 eV and –2.98 eV, respectively, using photoelectron spectroscopy and UV-Vis absorption spectra. Its fluorescence quenching properties were investigated through a Stern-Volmer quenching experiment. The PL intensity significantly decreased on increasing the concentration of TDPABF in a P3HT chloroform solution. The calculated Stern-Volmer quenching constant was 9.1 × 10⁴ M^?1, which is higher than that reported for PC₆₁BM.     

Absolute Configuration Determination of Two Optically Active Cyclopropyl-Ketoacids: (1′S, 3S) 3-(2′,2′-Dichloro-1′-methyl-cyclopropyl)-6-oxo-heptanoic acid and (1′S, 3S) 3-(2′,2′-Dibromo-1′-methyl-cyclopropyl)-6-oxo-heptanoic acid

Abstract  

The title compounds C₁₁H₁₆Cl₂O₃ (III) and C₁₁H₁₆Br₂O₃ (IV) have been prepared from (S)-Limonen. Their crystal structure and absolute configuration have been determined by X-ray analysis which confirmed the 1′S absolute configuration at the cyclopropyl moiety, in agreement with the known absolute configuration of the starting material. Both (III) and (IV) are orthorhombic, space group P2₁2₁2₁ with a = 7.2558(4) ? (for III) 7.4058(6) ? (for IV), b = 9.7885(5) ? (for III) 9.7459(7) ? (for IV), c = 17.7551(10) ? (for III) 18.0354(14) ? (for IV), α = 90°, β = 90°, γ = 90° and Z = 4.     

Syntheses,Structures and Optical Properties of a Series of Lanthanide Complexes with Chelidamic Acid and 4,4′-Bipyridyl

Abstract  

The title complexes, (C₁₀H₈N₂)·[Y(C₇H₃NO₅)(C₇H₄NO₅)·2H₂O]·3H₂O (1), (C₁₀H₈N₂)·[Er(C₇H₃NO₅)(C₇H₄NO₅)·2H₂O]·3H₂O (2), (C₁₀H₈N₂)·[La(C₇H₃NO₅)(C₇H₄NO₅)·2H₂O]·4.5H₂O (3), (C₁₀H₈N₂)·[Sm(C₇H₃NO₅)(C₇H₄NO₅)·2H₂O]·4.75H₂O (4), (C₁₀H₈N₂)·[Pr(C₇H₃NO₅)(C₇H₄NO₅)·2H₂O]·4.75H₂O (5) were synthesized and characterized by X-ray single-crystal diffraction. The crystal structures of 1–2 reveal that they are isomorphous, among which the metal atoms are all eight-coordinate with a distorted dodecahedron coordination geometry. The structures of 3–5 are isomorphic, among which the metal atoms are all nine-coordinate with distorted tricapped trigonal prismatic coordination geometries by two chelidamic acid ligands. Complexes 1–5 are formed into 3D networks by H-bonds. The optical properties of 1–5 were investigated in terms of fluorescent spectra, which all exhibit strong luminescence.     

Crystal structure of syn-1-acetyl-9′aH-8′- methoxyspiro[indole-3,2′-oxeto[3′,2′:4,5]furo[3,2-g][1] benzopyran]2,6′-dione

The crystal structure of syn-1-acetyl-9a-hydro-8-methoxyspiro[3H-indole-3,2(2aH) oxeto[3,2-g]furo[3,2-g]benzo[ b]pyran-2,6-dione 1 was determined by X-ray diffraction analysis. It possesses P2(1)/c space group symmetry, with a = 12.391(3), b = 15.035(3), c = 9.5435(19) Å, = 93.66(3), and D _calc. = 1.517 Mg/m³ for Z = 4.