Altering Hydrophilic and Hydrophobic Region via O–H···O and C–H···O Hydrogen Bonds and van der Waals Forces in Solagenin 6- O -( β -d -quinovopyranoside) Methanol Solvate Monohydrate

Abstract  The title compound, C₃₃H₅₂O₈·CH₃OH·H₂O, isolated from Solanum torvum, consisted of a solagenin 6-O-(β-d-quinovopyranoside) molecule, a methanol solvate and a hydrate. The six-membered rings A, B, C, F and G have chair conformations. The five-membered ring D adopts a half-chair conformation and the ring E adopts an envelope conformation. The A/B, B/C and C/D ring junctions are trans, whereas the D/E junction is cis. The molecular packing appeared to be established by alternation of a hydrophilic region involving methanol molecules, water molecules and the β-d-quinovopyranoside of the steroid nucleus via the classic O–H···O hydrogen bonds and a hydrophobic region consisted by the other part of the steroid nucleus via weak C–H···O hydrogen bonds and van der Waals forces. Graphical Abstract  The molecular packing of the title compound appeared to be established by alternation of a hydrophilic region involving methanol molecules, water molecules and the β-d-quinovopyranoside of the steroid nucleus via the classic O–H···O hydrogen bonds and a hydrophobic region consisted by the other part of the steroid nucleus via weak C–H···O hydrogen bonds and van der Waals forces.      

An X-Ray Crystallographic Study of the Novel Aminal bis-(<Emphasis Type="Italic">p</Emphasis>-Ethoxycarbonylphenylamino-)methane

Abstract  The crystal structure of bis-(p-Ethoxycarbonylphenylamino-)methane (1) has been determined by single crystal X-ray diffraction analysis. The bis-aminal (1) molecule is V-shaped and situated on a twofold axis passing through C1 with the phenyl rings forming a dihedral angle of 70.2(1)°. The carboxylate and phenyl groups are coplanar. The crystal structure of 1 is compared with the structure of the closely related aminals, 2–5. Crystal data: 1 C₁₉H₂₂N₂O₄, tetragonal, space group I4 ₁ cd (N.110), a = 20.4760(7) Ǻ, b = 20.4760(7) Ǻ, c = 8.2984(3) ?, and V = 3477.7(2) ?³, for Ζ = 8. Index Abstract  The crystal structure of bis-(p-ethoxycarbonylphenylamino-)methane (1) has been determined by single crystal X-ray diffraction analysis.      

Crystal Structure of the Radical-Cation Salt (<Emphasis Type="Italic">o</Emphasis>-Me<Subscript>2</Subscript>TTF)I<Subscript>3</Subscript> with Close Intermolecular Sulfur Contacts

Abstract  The synthesis and crystal structure of the organic radical-cation salt (o-Me₂TTF)I₃ is described. The salt crystallizes in the monoclinic space group P2 ₁ /n with a = 10.927(2) ?, b = 11.904(2) ?, c = 12.660(2) ?, β = 115.174(5)°. The bond length of the central C=C bond in o-Me₂TTF is 1.401(1) ?, indicating an approximate oxidation state of +1 for the o-Me₂TTF radical cation. Graphical Abstract  The X-ray crystallographic structure of the radical cation salt (o-Me₂TTF)I₃ has been determined and its structural properties and synthetic preparation are discussed.      

Synthesis and Crystal Structure of Benzoyloxymethyl (4α,8β,13β)-13-methyl-16-oxo-17-norkauran-18-carbonate Ester

Abstract  Isosteviol derivative: benzoyloxymethyl (4α,8β,13β)-13-methyl-16-oxo-17-norkauran-18-carbonate ester was synthesized by esterification of isosteviol with chloromethyl benzoate and its crystal structure was determined by X-ray diffraction method. The compound crystallizes in the triclinic space group P1 with unit cell parameters: a = 8.784(3) ?, b = 9.079(3) ?, c = 15.950(6) ?, α = 79.343(6)°, β = 79.061(5)°, γ = 89.849(5)°, Z= 2. The conformation of rings A and B is chair, whereas the conformation of ring C is unsymmetrical twist chair. The carbonyl group at the C20 is coplanar with the benzene ring. The fragment of the ester group occupying the pseudoaxial site of C1 position adopts a zigzag conformation. Index Abstract  Isosteviol derivative: benzoyloxymethyl (4α,8β,13β)-13-methyl-16-oxo-17-norkauran -18-carbonate ester was synthesized and its crystal structure was determined by X-ray diffraction method.      

Crystal Structure of<Emphasis Type="SmallCaps"> D</Emphasis>(−)-amino-(4-hydroxyphenyl)acetate,the Zwitter Ionic Form of Biologically Active<Emphasis Type="SmallCaps"> D</Emphasis>(−)-4-hydroxyphenylglycine

Abstract  Crystals of D(−)-amino-(4-hydroxyphenyl)acetate were analyzed by single crystal X-ray diffraction. The compound crystallizes in the chiral space group, P2₁ (No. 4) with one molecule in the asymmetric unit and a = 5.0994(10) ?, b = 9.3169(19) ?, c = 8.6960(17) ?, β = 91.50(3)°. The intermolecular interactions in the crystal have been visualised by plotting the Hirshfeld surface of the molecule. Graphical Abstract  The extensive hydrogen bonding network in D(−)-amino-(4-hydroxyphenyl)acetate has been described and visualised by plotting its Hirshfeld surface.      

Intermolecularly Associated Carboxylic Acid Dimers in the Supramolecular Assembly of (R)-1,4-Benzodioxane 2-Carboxylic Acid

Abstract  The title compound, C₉H₈O₄, (I), crystallizes in the monoclinic space group P 21/c with unit cell parameters a = 7.3380(5) ?, b = 9.3790(7) ?, c = 12.3172(9) ?, β = 90.687(7)°, Z = 4. The molecule consists of a benzene ring fused to a 1,4 dioxane ring in a half-chair conformation with a carboxylic acid group bonded at the dioxane 2-position. The carboxylic acid group forms a classic O–H···O hydrogen bonded dimer with an O···O distance of 2.6292(12) ? in a R₂² (8) graph-set motif which links the molecules into pairs around inversion centers in a supramolecular assembly in the unit cell. The dihedral angle between the mean planes of the R₂² (8) graph-set motif’s of two adjacent dimers in the unit cell is 75.7(5)°. The mean plane of an R₂² (8) graph-set motif makes an angle of 88.4(5)° with the mean plane of the benzene ring in the same dimer and 13.1(2)° or 13.4(7)° with the mean plane of a benzene ring from an adjacent dimer. Additional weak Cg π-ring intermolecular interactions significantly influence the bond distances, bond angles and torsion angles of the dioxane ring and attached carboxyl group. Comparison to a MOPAC AM1computational calculation provides support to these observations. Graphical Abstract  The association of carboxylic acid dimers in the supramolecular assembly of (R)-1,4-benzodioxane 2-carboxylic acid is investigated by examination of its crystal structure. Its geometric and packing parameters are described and compared to a MOPAC AM1 computational calculation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Synthesis and X-ray Structure of (2R, 3R, 4R, 5R)-3,4,5-Tris-Benzyloxy-2-Benzyloxymethyl-Piperidin-1-ol, the N-Hydroxy-Analogue of 2,3,4,6-Tetra-O-Benzyl-1-Deoxymannojirimycin

Abstract  The title compound 8 was obtained for the first time by hydride-mediated reduction of the d-fructose-derived nitrone 9. The N-hydroxy piperidine 8 is a precursor of the N-hydroxy analogue of DMJ, a potent inhibitor of α-mannosidases. It was isolated as colorless crystals (triclinic, P1 space group) exhibiting the following cell parameters: a = 9.947(2) ?; b = 12.155(2) ?; c = 13.864(5) ?; α = 100.98(3)°; β = 97.94(2)°; γ = 109.50(1)°. The X-ray analysis of a monocrystal of 8 allowed confirmation of its relative configurations and showed the anti orientation of its N-hydroxy group. This structural feature should be useful for considering the interaction of N-hydroxy iminosugars with the recognition site of carbohydrate processing enzymes. Index Abstract  The title compound 8 was prepared for the first time by hydride-mediated reduction of the d-fructose-derived nitrone 9. Compound 8 is a precursor of the N-hydroxy analogue of DMJ, a potent inhibitor of α-mannosidases. The X-ray analysis allowed confirmation of the relative configurations of 8 and showed the anti orientation of its N-hydroxy group. This structural feature will be useful for considering the interaction of N-hydroxy-iminosugars with specific biological targets.      

Solid State Structure of 6,7-Dihydro-1,4-Di(2′-Pyridyl)-5<Emphasis Type="Italic">H</Emphasis>-Cyclopenta[d]Pyridazine

Abstract  The X-ray structure of 6,7-dihydro-1,4-di(2′-pyridyl)-5H-cyclopenta[d]pyridazine ligand (5-dppn) shows the existence of a trans/trans conformation. The 5-dppn crystallizes in a triclinic space group P-1 with a = 7.1048(15) ?; b = 9.008(2) ?; c = 10.986(3) ?; α = 88.279(16)°; β = 85.454(15)°; γ = 69.104(12)°; V = 654.7(3) ?³ and Z = 2. The analysis of 5-dppn crystal structure demonstrates the presence of edge-edge Ar–H···N and face-face Aliph-H···N centrosymmetric dimer interactions. The unit cell packing arrangement confirmed the presence of two molecules opposite to each other. Index Abstract  The X-ray structure of 6,7-dihydro-1,4-di(2′-pyridyl)-5H-cyclopenta[d]pyridazine ligand (5-dppn) shows the existence of a trans/trans conformation.      

The First Coordination Compound with 5-methylisoxazole-3-carboxylate: Synthesis and Structural Characterization of [Cu(L<Subscript>2</Subscript>)(H<Subscript>2</Subscript>O)] · H<Subscript>2</Subscript>O

Abstract  The title compound, aquabis(5-methylisoazole-3-carboxylato-O,N)copper(II) monohydrate, [Cu(L₂)(H₂O)] · H₂O is synthesized and characterized by X-ray diffraction, elementary analysis, and IR. The ligand coordinates to the copper center in a bidentate O,N fashion through the carboxylic acid moiety and the heteroaromatic nitrogen atom. The complex crystallizes in the triclinic space group with unit cell parameters a = 8.4080(12)?, b = 8.810(3), c = 10.318(2)?, α = 110.08(3)°, β = 104.81(2)°, γ = 103.149(16)°, V = 650.9(3)?³, Z = 2. In addition, the synthesis of the free acid 5-methylisoazole-3-carboxylic acid and pyridine containing complex bis(5-methylisoazole-3-carboxylato)bispyridinecopper(II) monohydrate is described. Index Abstract  Synthesis and crystal structure of aquabis(5-methylisoazole-3-carboxylato-O,N)copper(II)monohydrate. The first coordination compound of 5-methylisoxazole-3-carboxylic acid.      

Synthesis,Characterization and Crystal Structure of Iridium(III)bis(2-<Emphasis Type="Italic">p</Emphasis>-tolyl-benzothiazolato-N,C<Superscript>2</Superscript>)(acetylacetonate)

Abstract  A novel thiazole-based iridium (III) complex (iridium(III)bis(2-p-tolyl-benzothiazolato-N,C²)(acetylacetonate)) has been prepared and fully characterized by EA, IR, ¹H-NMR and MS. The molecular structure of the complex has been determined by single crystal X-ray diffraction analysis. The iridium (III) center adopts a distorted octahedral geometry with cis-O–O, cis-C–C, and trans-N–N chelate disposition. The complex crystallizes in the orthorhombic Pbca space group with cell parameters a = 10.1388(7) ?, b = 18.3565(12) ?, c = 31.021(2) ?, α = β = γ = 90 ° and Z = 8. The electronic absorption and emission spectra of this complex have been investigated. Index Abstract  A novel thiazole-based phosphorescent iridium (III) complex (iridium(III) bis (2-p-tolyl-benzothiazolato-N,C²)(acetylacetonate)) has been prepared and fully characterized by EA, IR, ¹H-NMR, MS and X-ray diffraction analysis.     

4-Chloro-2,6-bis(hydroxymethyl)pyridinium Chloride and 4-Dimethylamino-2,6-bis(hydroxymethyl)pyridinium Chloride Hemihydrate

Abstract  Two substituted pyridinium chloride salts, namely 4-chloro-2,6-bis(hydroxymethyl)pyridinium chloride (triclinic, P-1, a = 6.0651(8) ?, b = 8.4393(8) ?, c = 8.6554(9) ?, α = 78.845(1)°, β = 83.156(1)°, γ = 89.047(1)°; V = 431.55(8) ?³; Z = 2) and 4-dimethylamino-2,6-bis(hydroxymethyl)pyridinium chloride hemihydrate (orthorhombic, Aba2, a = 17.2179(14) ?, b = 17.6332(15) ?, c = 7.2068(6) ?; V = 2188.0(3) ?³; Z = 4), have been structurally characterized. Hydrogen bonding and van der Waals contacts are evident in both structures. Furthermore, the 4-dimethylamino derivative features a trigonal planar dimethylamino group with some π interaction between the nitrogen atom and the pyridine ring. Graphical Abstract  Two compounds, namely 4-chloro-2,6-bis(hydroxymethyl)pyridinium chloride and 4-dimethylamino-2,6-bis(hydroxymethyl)pyridinium chloride hemihydrate, have been spectroscopically and structurally characterized.      

High Temperature Ionic Liquids: Thermal Properties and Dimorphism in [1-(Methoxycarbonyl) Ethyl] Triphenylphosphonium <Emphasis Type="Italic">p</Emphasis>-Toluenesulfonate

Abstract  Investigation of the thermal properties of triphenylphosphonium p-toluenesulfonates, which are high temperature ionic liquids, reveals that they solidify to a noncrystalline material on fast cooling from the melt. During the study, a second crystalline form of [1-(methoxycarbonyl) ethyl] triphenylphosphonium p-toluenesulfonate (form II) has been obtained. Form II is monoclinic P2₁/c, with a = 11.002(5)?, b = 12.793(5)?, c = 18.805(5)?, and β = 102.498(5)°. Comparison with form I reveals the existence of a common robust structural feature involving interactions between cations and anions. Graphical Abstract  Investigation of thermal properties of ionic liquids has revealed a second crystalline form of [1-(methoxycarbonyl) ethyl] triphenylphosphonium p-toluenesulfonate.      

Crystal Structure of N-(tert-Butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)cyclohexane Carboxamide

Abstract  The crystal structure of N-(tert-butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)-cyclohexane-carboxamide 1 has been determined. The title compound crystallized in the orthorhombic space group pbca with cell parameters, a = 10.6556(6) ?, b = 18.0132(11) ?, c = 19.5513(12) ?, v = 3752.7(4) ?³, Z = 8, D _cal = 1.269 Mg/m³ at T = 120 K. The structure refined by full-matrix least-squares procedures to find R ₁ = 0.0463 and wR ₂ = 0.0937 for 3059 reflections. The soxazole ring isn’t coplanar with the phenyl ring. Index Abstract  The crystal structure of N-(tert-butyl)-1-(3,5-dioxo-2-phenyltetrahydro-4-isoxazolyl)-cyclohexane-carboxamide 1 has been studied.      

Crystal and Molecular Structure of Diterpenoid Alkaloid 3-Acetylaconitine

Abstract  3-Acetylaconitine (1), C₃₆H₄₉NO₁₂, was isolated from the ammonium hydroxide wetted root of A. szechenyianum Gay. X-ray diffraction analysis demonstrated that it consists of four-six-membered rings A, B, C, D and two-five-membered rings E, F. The fused-ring system A, B, C and D are in chair, chair, chair and boat conformations, respectively; ring E is in a half-chair; and ring F is in an envelope confirmation. The crystal of 3-acetylaconitine is in orthorhombic crystal system with space group P2₁2₁2₁, lattice constants: a = 9.2002(8) ?, b = 11.06454(9) ?, and c = 33.072(3) ?, V = 3543.3(5) ?³, Z = 4. Index Abstract  3-Acetylaconitine, C₃₆H₄₉NO₁₂, was isolated from the ammonium hydroxide wetted root of A. szechenyianum Gay, and its crystal and molecular structure was determined by X-ray diffraction analysis.      

3-Methyl-3a,4-Dihydro-3H-Thiochromeno[4,3-c]isoxazol

Abstract  The crystal structure of the title compound, C₁₁H₁₁NOS, was determined by an X-ray diffraction analysis. The compound crystallizes in the monoclinic space group P2₁/c with cell parameters a = 10.533(2) ?, b = 12.7826(19) ?, c = 7.6491(17) ?, β = 107.997(17)^°, V = 979.5(3) ?³ and Z = 4. The S containing heterocycle adopts a sofa conformation, whereas the 5-membered ring adopts an envelope conformation. The crystal packing is characterized by weak C–H···N contacts and π-stacking interactions. Graphical Abstract  The title compound, 3-methyl-3a,4-dihydro-3H-thiochromeno[4,3-c]isoxazol was synthesized by an 1,3 dipolar cycloaddition reaction and its crystal structure determined. Single crystal X-ray diffraction analysis reveals that the aromatic 6-membered ring is planar, whereas the ring containing the S atom adopts a sofa conformation and the 5-membered ring an envelope conformation. The methyl group is in an equatorial position.      

Synthesis of (2,4-Diamino-5-(3′,4′,5′-trimethoxybenzyl) Pyrimidine) Copper (II) Complex at 20–25 °C and its Structural Characterization

Abstract  The title copper (II) complex with Trimethoprim was prepared at 20–25 °C and its crystal structure was determined by single crystal X-ray diffraction. Compound (C₃₆H₅₀Cu₃N₈O₁₆) is triclinic, space group P-1 with a = 6.4642(5) ?, b = 12.5495(9) ?, c = 13.4911(10) ?, α = 77.518(1)°, β = 85.326(1)°, γ = 84.413(2)°, Z = 1. In this compound, three copper atoms are bonded to each other, two terminal coppers are bonded to three oxygen atoms and N₁ of pyrimidine ring of Trimethoprim and central copper is bonded to four oxygen atoms. The amino nitrogen atoms are not involved in the coordination to the metal. Graphical Abstract  To enhance the activity of trimethoprim, its derivative was prepared and there bacterial activity against several bacteria was analyzed.      

Synthesis and Crystal Structure of 5-[2-(6-bromonaphthalenyloxymethyl)]-3-(4-morpholinomethyl)-1,3,4-oxadiazole-2(3<Emphasis Type="Italic">H</Emphasis>)-thione

Abstract  The title compound, C₁₈H₁₈BrN₃O₃S, a derivative of 1,3,4-oxadiazole, crystallizes in the triclinic space group P-1 with unit cell parameters a = 6.8731(3), b = 8.9994(4), c = 15.7099(6) ?, α = 92.779(3)°, β = 130.575(3)°, γ = 107.868(4)°, Z = 2. The dihedral angle between the mean planes of the planar naphthyl and morpholine (chair) rings with the planar oxadiazol ring is 50.1(8) and 76.8(6)°, respectively. The planar naphthyl ring is twisted 52.2(5)° with the mean plane of the morpholine ring. A group of four intermolecular close contacts are observed between a bromine atom and hydrogen atoms from the closely packed naphthyl, morpholine and oxy–methyl groups in the unit cell. These molecular interactions in concert with an additional series of π–π stacking interactions that occur between the center of gravity of the two 6-membered rings of the naphthalene group influence the twist angles of each of these three groups. A MOPAC AM1 calculation of the conformation energy of the crystal structure [226.0128(9) kcal] compared to that of the minimum energy structure after geometry optimization [29.9744(1) kcal] reveals a significantly reduced value. The twist angles of the three groups above also change after the AM1 calculation giving support to the influence of both intermolecular C–H···Br short-range interactions and Cg π–π stacking interactions on these angles which therefore play a role in stabilizing crystal packing. Graphical Abstract  Crystal structure of 5-{[(6-bromonaphthalen-2-yl)oxy]methyl}-3-(morpholin-4-ylmethyl)-1,3,4-oxadiazole-2(3H)-thione, C₁₈H₁₈BrN₃O₃S, is reported and its geometric and packing parameters described and compared to a MOPAC computational calculation. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Spectroscopic Studies and Crystal Structure of (<Emphasis Type="Italic">Z</Emphasis>)-6-[(2-hydroxyphenylamino)methylene]-2-methoxycyclohexa-2,4-dienone

Abstract  The Schiff base (Z)-6-[(2-hydroxyphenylamino)methylene]-2-methoxycyclohexa-2,4-dienone has been synthesized from the reaction of 2-aminophenol with 2-hydroxy-3-methoxybenzaldehyde. The title compound has been characterized by elemental analysis, FT-IR, ¹H-NMR, ¹³C-NMR and UV–Visible techniques. The structure of the title compound also was determined crystallographically. The crystal structure has been solved by direct methods and refined by full-matrix least squares. The title compound crystallize in the monoclinic space group P2₁/c with a = 10.438(1), b = 8.851(1), c = 12.746(1) ?, β = 95.72(1)°, V = 1171.7(2) ?³, D _x  = 1.379 g cm⁻³, respectively (R1 = 0.0522 and wR2 = 0.126 for 1442 reflections [I > 2σ(I)]). Index Abstract   N-salicylideneaniline derivatives have been shown to exist as tautomeric forms due to intramolecular proton shifts between the phenol-oxygen and the imine-nitrogen, via intramolecular hydrogen bonding O–H···N or O···H–N.      

X-ray Structure Investigation of 20-<Emphasis Type="Italic">O</Emphasis>-β-<Emphasis Type="SmallCaps">d</Emphasis>-glucopyranosyl-20(<Emphasis Type="Italic">S</Emphasis>)-protopanaxadiol

Abstract  20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol (I) has been isolated as a metabolite of ginseng saponins by Paecilomyces bainier. The crystal structure of (I) was also investigated by single crystal X-ray diffraction analysis. It crystallizes in the monoclinic space group P2₁, with a = 15.99 2 (3) ?, b = 11.960 (19) ?, c = 20.127 (3) ?, β = 101.85 (4)°, and V = 3767.5 (11) ?³, Z = 4, R _int = 0.1129, ωR(F ²) = 0.1749, F(000) = 1,448. The title compound is a dammarane-type triterpenoid, and the four rings of this compound connect with each other in trans characteristics,with the three-six-membered rings in chair conformation and the five-membered ring adopting envelope one. A β-d-glucopyranosyl group and a 2-methyl-2-pentenyl group connect to C20 of S configuration. The space symmetrical motif is adopted and each packing unit-cell contains two symmetrical compound (I) molecules and four H₂O molecules. The hydrogen-bonding (both intra- and inter-molecular) interactions play a major role in this structural association. Index Abstract  In the present paper, the single-crystal structure of 20-O-β-d-glucopyranosyl-20(S)-protopanaxadiol was determined by X-ray analysis      

Synthesis and Structure of [Fe<Subscript>3</Subscript>O(O<Subscript>2</Subscript>CCH<Subscript>2</Subscript>OMe)<Subscript>6</Subscript>(H<Subscript>2</Subscript>O)<Subscript>3</Subscript>][FeCl<Subscript>4</Subscript>]

Abstract  The structure of [Fe₃O(O₂CCH₂OMe)₆(H₂O)₃][FeCl₄] · 2.5H₂O has been determined. The three iron atoms and the μ₃-oxo are coplanar. Each carboxylic ligand is bidentate and links two iron atoms in the cluster. The clusters are linked by intra-trimer hydrogen bonding to form a zigzag motif that forms sheets via hydrogen bonding involving disordered waters of hydration. The [FeCl₄]⁻ anion is intercalated between the hydrogen-bonded sheets. Crystal data: space group P2₁/n, a = 10.276(2), b = 22.793(5), c = 17.091(3) ?, β = 96.66(3)°, V = 3976(1) ?³, Z = 4, R = 0.0837, wR ₂ = 0.1836. Graphical Abstract  The structure of [Fe₃O(O₂CCH₂OMe)₆(H₂O)₃][FeCl₄] · 2.5H₂O has been determined in which the clusters are linked by intra-trimer hydrogen bonding to form a zigzag motif that forms sheets via hydrogen bonding involving disordered waters of hydration.