Crystal Structure of 3β-Hydroxy-16α-methylpregn-5-en-20-one

Abstract  

The crystal structure of the title compound, 3β-hydroxy-16α-methylpregn-5-en-20-one, C₂₂H₃₄O₂, was determined by direct methods using single crystal X-ray diffraction data. The compound crystallizes in the triclinic space group P1 with unit-cell parameters: a = 6.235(1) ?, b = 6.282(1) ?, c = 12.877(3) ?, α = 96.672(4)°, β = 98.746(4)°, γ = 106.838(4)°, Z = 1. The structure was refined by full-matrix least-squares to R = 0.0573 for 2,196 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 envelope 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 8.0°. Molecules are connected via C–H···O hydrogen bonds to form straight chains along the c-axis of the unit cell. The straight chains are packed together to form layers.     

Hydrogen Bonding Patterns in Trimethoprimium Cinnamate 1.52 Hydrate

Abstract  

In the title compound, [C₁₄H₁₉N₄O₃ ⁺, C₉H₅ O₂ ⁻, H₂O, O0.52] the asymmetric unit contains a protonated trimethoprim cation and a cinnamate anion and two water molecules. The crystal structure was determined by single crystal X-ray diffraction. This compound crystallized in the triclinic system; space group P−1 with the unit cell parameters a = 10.010(2) ?, b = 10.339(3) ?, c = 13.486(8) ?, α = 105.32(3)°, β = 109.88(3)°, γ = 100.89(3)°, V = 1204.6(10) ?³, Z = 2. The cinnamate group is disordered. The trimethoprim (TMP) molecule is protonated at one of the pyrimidine nitrogen atoms. The carboxylate group of the cinnamate anion interacts with the protonated pyrimidine atom N1 and the 2-amino group via a pair of N–H···O hydrogen bonds, generating the R₂²(8) ring motif. The inversion related TMP cations are paired via N–H···N hydrogen bonds. In addition to the base pairing, the O1W atom bridges the 2-amino and 4-amino groups on either side of the paired bases, resulting in a self complementary DADA array. Two inversion related TMP cations and water molecules (O1W) are linked via N–H···O and O–H···O hydrogen bonds, forming a 22 membered ring with graph-set R₄⁴(22).     

Crystal Structure?4-(2,4-Dihydroxybenzylideneamino)-5-methyl-2H-1,2,4-triazol-3(4H)-one

Abstract  

The title compound (I), 4-(2,4-dihydroxybenzlideneamino)-5-methyl-2H-1,2,4-triazol-3(4H)-one was characterized by single crystal X-ray diffraction. This crystal is monoclinic, space group P2₁/c with a = 10.1447(7) ?, b = 7.0972(3) ?, c = 14.6726(10) ?, β = 98107(5)°, V = 1045.85(11) ?³, Z = 4, D _c = 1.487 g/cm³, F ₀₀ = 488, R = 0.039 and wR = 0.1025, S = 1.003, T = 293 (2) K. The title molecule is planar: the angle between the triazole ring and benzene ring is 179.1(1)°. The crystal structure contains two intramolecular (O–H···N and C–H···O) and three intermolecular interaction (O–H···N, N–H···O, and C–H···O). In addition, there is also π–π interactions.     

Crystal and Molecular Structure Studies of 1′-Benzyl-8-(4-fluorobenzyl)-8-azaspiro[bicyclo-[3.2.1]octane-3,4′-imidazolodine]-2′,5′-dione

Abstract  

The title compound, C₂₃H₂₃FN₃O₂ has been synthesized and the structure was investigated by X-ray diffraction studies. The compound crystallizes in the triclinic crystal class in the space group P[`1]P\overline{1} with cell parameters a = 9.345(2) ?, b = 10.940(3) ?, c = 11.986(4) ?, α = 72.349(6)°, β = 68.106(18)°, γ = 66.867(5)°, Z = 2 and V = 1027.8(5) ?³. The hydantoin ring adopts a planar conformation and is affected by the π conjugation. The pyrrolidine and piperidine rings in the bicyclo octane moiety adopt envelope and chair conformations respectively. The structure exhibits both inter and intramolecular hydrogen bonds of the type N–H···O, C–H···O and C–H···N. One of the oxygen atoms attached to the hydantoin ring simultaneously accepts two hydrogen bonds to form a three centered hydrogen bonding pattern.     

5,6-Dihydroxy-1,10-phenanthrolinium-1,10-ium dichloride

Abstract  

5,6-Dihydroxy-1,10-phenanthroline, obtained from recrystallization of a side-product of a condensation reaction between 1,10-phenanthroline-5,6-dione and 5,6-diamino-1,3-dimethyluracil, has been isolated as a dihydrochloride (C₁₂H₈N₂O₂·2HCl·0.5CH₃CN) by vapor diffusion of acetonitrile into an ethanol/HCl solution. The compound crystallizes in the triclinic space group P[`1] P\overline{1} with a = 5.8334(1) ?, b = 9.8041(2) ?, c = 11.9895(2) ?, α = 81.511(1)°, β = 76.395(1)°, γ = 81.429(1)°, and V = 654.48(2) ?³, Z = 2, R[F ² > 2σ(F ²)] = 0.028, and wR(F ²) = 0.078. The crystal packing is stabilized by two N–H⁺···Cl⁻ interactions (2.18(3) ?, 2.13(2) ?) and two O–H···Cl⁻ interactions (2.11(3) ?, 2.20(3) ?). Pi-stacking of the phenanthrolinium rings results in an interplanar distance of 3.431(5) ? with the phenanthrolinium ring centroids displaced from each other by ~6 ?. The results for this diprotonated species are compared to those reported by Lin et al. (Acta Cryst E65:o2367, 2009) for the monoprotonated form and this reveals the possibility of using the relative –OH/phenanthroline ring orientations as a qualitative diagnostic of metal–ligand interactions in metal complexes of this ligand (Larsson and Ohrstrom in Inorg Chim Acta 357:657, 2004; Guan et al. in Acta Cryst C64:m311, 2008).     

Synthesis, Crystal and Molecular Structure of 1-(2-Chlorobenzyl)-2-methylthio-1H-benzimidazole

Abstract  

1-(2-Chlorobenzyl)-2-methylthio-1H-benzimidazole compound has been synthesized and characterized by elemental analysis, IR and ¹H-NMR spectroscopy and single crystal X-ray diffraction. The compound crystallizes in the triclinic space group P-1 with unit cell parameters a = 17.201 ?, b = 5.873 ?, c = 24.791 ?, α = 67.410(10)°, β = 74.083(11)°, γ = 81.858(12)°. In the crystal packing, no classic hydrogen bonds are founded, but C–H···π interactions are being between the molecules. The molecular geometry and vibrational frequencies of (C₁₅H₁₃ClN₂S) in the ground state have been calculated by using Hartree–Fock (HF) and Density Functional Method (DFT/B3LYP) with 6-31G(d) basis set. The optimized geometric bond lengths and bond angles obtained by using HF and DFT (B3LYP) show the best agreement with the experimental data.     

Crystal Structures of 1,7-Bis(furyl)-4-(1,3-dithiolan-2-ylidene)-1,6-heptadiene-3,5-dione and 1,7-bis(thienyl)-4-(1,3-dithiolan-2-ylidene)-1,6-heptadiene-3,5-dione

Abstract  

The title compounds (bis(alkenoyl) ketene dithioacetals) were prepared starting from the cyclic acyl ketene dithioacetal and aromatic aldehydes. These compounds were characterized by IR, ¹H NMR, mass spectral studies and X-ray crystal structure analysis. The bis(furyl) ketene dithioacetal crystallized in the space group P[`\text1] P{\bar{\text{1}}} with unit cell dimensions a = 7.7626(12) ?, b = 9.0217(13) ?, c = 26.827(5) ?, α = 86.271(14)°, β = 87.643(14)°, γ = 66.286(11)° and the structure was refined to an R-factor of 0.0528 while bis(thienyl) ketene dithioacetal crystallized in the space group P2₁/c with unit cell dimensions a = 10.2433(9) ?, b = 10.4142(6) ?, c = 18.0973(18) ?, β = 106.0° and the structure was refined to an R-factor of 0.0446. The ketenedithioacetal functionality present between the carbonyl groups prevents the possibility of keto-enol tautomerization in these compounds. In both the crystal structures, the crystal packing is stabilized by C–H···O hydrogen bonds as well as van der Waals interactions.     

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.     

Synthesis and Crystal Structure of a Fe(III) Complex with an Isonicotinyl Hydrazone Ligand, [Fe(N-Isonicotinamidosalicylaldimine)Cl<Subscript>2</Subscript>]

Abstract  

A new complex [Fe(N-isonicotinamidosalicylaldimine)Cl₂] has been synthesized by template reaction at room temperature and structurally characterized by X-ray single-crystal analysis. The complex crystallizes in triclinic crystal system, Pī space group, a = 7.273(6) ?, b = 10.015(8) ?, c = 10.479(8) ?, α = 71.067(10)°, β = 89.964(11)°, γ = 75.528(10)°, V = 696.4(9) ?³ and Z = 2. The coordination geometry around the Fe(III) ion is a distorted trigonal bipyramid with a O₂N₁Cl₂ donor set. In the crystal structure, N–H···Cl, C–H···O and C–H···Cl hydrogen bonds and π···π stacking interactions involving aromatic and unclosed π-systems link the molecules to form supramolecular double layers.     

N–H···π Interactions in Two Isomers of an Amino Group Containing <Emphasis Type="Italic">bis</Emphasis>-Phenol

Abstract  

Crystal structures of two bis-phenols namely bis-(3,5-dimethyl-2-hydroxyphenyl)(3-amino phenyl)methane 1 and bis-(3,5-dimethyl-4-hydroxyphenyl)(3-aminophenyl) methane 2 are determined. The compound 1 crystallises in monoclinic P2₁/c with a = 12.2579(16) ?, b = 16.0906(19) ?, c = 10.6664(13) ?, β = 115.417(7)°, V = 1900.2(4) ?³ whereas 2 crystallizes in monoclinic C2/c, a = 9.2538(2) ?, b = 18.6579(4) ?, c = 23.2725(5) ?, β = 98.796(2)°, V = 3970.89(15) ?³. The crystal lattice of both the compounds shows presence of N–H···π interactions but no O–H···π interactions.     

The Crystal Structure and Conformational Studies of Acridinedione Derivatives

Abstract  

Two crystal structures of acridinediones namely, TMHAD and MPHAD were studied by X-ray crystallographic method in view of their occurrence in numerous commercial products including pharmaceuticals, fragrances and dyes. Crystal data of TMHAD are: C₁₇H₂₃NO₂, orthorhombic, Fdd2, with cell parameters a = 40.417(6) ?, b = 5.744(1) ?, c = 12.979(2) ?, V = 3013.1(7) ?³, Z = 8, D_cal = 1.205 Mg/m³, μ = 0.078 mm⁻¹. Crystal data of MPHAD are: C₂₀H₁₈NO₃; monoclinic, P2₁/c with cell parameters a = 10.182(9) ?, b = 17.105(14) ?, c = 10.895(9) ?, β = 117.857(1)°, V = 1678(2) ?³, Z = 4, D_cal = 1.268 Mg/m³, μ = 0.085 mm⁻¹. Both data were collected using λ (MoK_α) = 0.71073 ?. The central ring in the acridinedione moieties tends to be planar while the outer two rings adopt sofa conformations. Intermolecular interactions of C–H···O type of hydrogen bond help the molecules to stabilize into the crystal packing. Interestingly, a week forces of C–H···π interactions also helps the molecules for stabilization.     

Synthesis and Crystal Structures of Dioxomolybdenum(VI) Complexes with ONS-Donor Ligands

Abstract  

Three dioxomolybdenum complexes namely dioxo(5-chlorosalicylaldehyde thiosemicarbazonato) dimethylsulfoxide molybdenum(VI) (C1), dioxo(5-chlorosalicylaldehyde 2-ethylthiosemicarbazonato) dimethylsulfoxide molybdenum(VI) (C2) and dioxo(5-chlorosalicylaldehyde N-phenylthiosemicarbazonato) dimethylsulfoxide molybdenum(VI) (C3) were prepared. The compounds all crystallize in the triclinic space group P-1 with a = 7.3184(3) ?, b = 7.5035(3) ?, c = 14.9713(6) ?, α = 85.005(2)°, β = 85.616(2)°, γ = 66.987(2)° for C1, a = 8.2339(1) ?, b = 10.1739(1) ?, c = 10.4017(1) ?, α = 78.486(1)°, β = 89.312(1)°, γ = 81.730(1)° for C2, a = 7.0591(1) ?, b = 9.5603(1) ?, c = 14.5762(2) ?, α = 76.280(1)°, β = 81.351(1)°, γ = 81.985(1)° for C3. In general, the overall geometry of these complexes can be regarded as a distorted octahedron with the tridentate thiosemicarbazonato ligands (L²⁻) bonded to the MoO₂ ²⁺ core, with the imine nitrogen, phenoxyl oxygen, sulfur atom and one of the terminal oxygen atoms of the dioxomolybdenum occupying the equatorial position. The sixth coordination site is occupied by the dimethylsulfoxide (DMSO) solvent molecules. The adjacent molecules of C1 are linked by N–H···N intermolecular hydrogen bonding, forming polymeric chains that run parallel to the bc plane. On the other hand, C2 is a discrete molecule while the molecules of C3 associate via weak N–H···O hydrogen bonding interaction to form a polymeric chain that runs along the a-axis.     

Structural Studies of (Pyridine)<Subscript>3</Subscript>ZnFe(CO)<Subscript>4</Subscript> and (Pyridine)(Neocuproin)CdFe(CO)<Subscript>4</Subscript>

Abstract  

The structure of the previously reported (py)₃ZnFe(CO)₄ (py = pyridine) has been determined, confirming the monomeric nature of this species. The complex has average Zn–N and Zn–Fe bond lengths of 2.0970(7) and 2.4017(3) ?, and features a coordination geometry about Fe which is intermediate between trigonal bipyramidal and face monocapped tetrahedral. The space group is P2₁/c, with a = 8.22080(10) ?, b = 16.1668(3) ?, c = 15.4669(3) ?, β = 102.5869(11)°, V = 2006.21(6) ?³, D_calc. = 1.558 g/cm³ at 150(1) K. A monomeric cadmium analogue, (pyridine)(neocuproin)CdFe(CO)₄, has also been synthesized, and found to possess a similar geometry, with average Cd–N and Cd–Fe bond lengths of 2.352(2) and 2.5380(5) ?. The space group is P[`1] P\overline{1} with a = 10.8900(2) ?, b = 11.3042(3) ?, c = 15.5488(4) ?, α = 85.1251(10)°, β = 84.3468(14)°, γ = 72.0377(15)°, V = 1808.93(7) ?³, D_calc. = 1.478 g/cm³ at 150(1) K.     

Synthesis and Crystal Structure of [Te{S(C<Subscript>6</Subscript>H<Subscript>3</Subscript>S)<Subscript>2</Subscript>O}]: A Tetracyclic Tellurium(II) Compound Displaying a Boat–Chair Conformation

Abstract  

The synthesis and molecular structure of (phenoxathiin-4,6-dithiolate)tellurium(II) is described. [Te{S(C₆H₃S)₂O}] was synthesized from the reaction of 4,6-dimercaptophenoxatiin and TeCl₄ in 36% yield. The crystal structure was determined by single crystal X-ray diffraction analysis. Crystal data: [Te{S(C₆H₃S)₂O}], formula weight = 389.95, crystallized in monoclinic system, space group P2(1)/n with a = 7.7898(10) ?, b = 18.513(2) ?, c = 8.9898(11) ?, β = 105.974(2)°, V = 1246.4(3) ?³ and Z = 4. The tetracyclic compound is non-planar with a di-coordinate Te^II atom. The eight-membered central ring is in a boat–chair conformation. The title compound displays weak intermolecular contacts Te–S, S–S and C–H⋯S.     

The Crystal Structures of (Z)-Ethyl 2-(4-chlorophenyl)-3-(2,4-difluorophenyl-amino)acrylate and its Analogues

Abstract  

The title compound, C₁₇H₁₄ClF₂NO₂, crystallizes in monoclinic space group P2₁/c with unit cell dimension of a = 16.276(3) ?, b = 7.5030(15) ?, c = 13.812(3) ?, α = 90°, β = 111.11(3)°, γ = 90° and Z = 4. The structure of the title compound reveals a Z configuration with respect to the C=C double bond in aminoacrylate fragment. The molecule is stabilized by intramolecular N–H···F and N–H···O hydrogen bonds. In the ethyl 2-aryl-3-arylaminoacrylates, electronic properties of the substituents in the aniline motif clearly affected the attached C–N bond length, and such effect is very little relative to Z-/E-configuration with respect to the C=C double bond.     

Novel Methyl 4,6-O-benzylidene-3-ketoglucopyranosid-fused γ-lactam: Synthesis and Crystal Structure

Abstract  

The title compound methyl 4,6-O-benzylidene-3-ketoglucopyranosid-fused γ-lactam was synthesized from 2-oxoglucopyranoside in one pot via multi-step reaction sequence under mild conditions. It was characterized by HRMS, ¹H and ¹³C-NMR, IR, elemental analysis and single crystal X-ray diffraction. The crystal belongs to orthorhombic P2(1)2(1)2(1) space group with unit cell parameters a = 6.1840 (12) ?, b = 10.372 (2) ?, c = 25.702 (5) ?, V = 1648.5 (6) ?³, Z = 4, D_c = 1.343 Mg/m³, λ = 0.71073 ?, μ(Mo Kα) = 0.102 mm⁻¹, F(000) = 704. X-ray diffraction analysis reveals that the compound adopts chair-chair conformation. The newly formed γ-lactam moiety is fused to glucopyranoside ring by C2 to form spirosugar. The crystal structure is stabilized by N–H···O2 hydrogen bond.     

Synthesis and Crystal Structure of (E)-1-(2,3-Dihydroxybenzlidene)-4,4-Dimethythiosemicarbazide

Abstract  

The Schiff base C₁₀H₁₃N₃O₂S is monoclinic, having unit cell parameters a = 9.788(1) ?, b = 9.615(1) ?, c = 12.605(1) ?, β = 108.41(1)° and V = 1125.56(2) ?³ and belongs to P2_1/n space group. The molecule is almost planar. The two hydroxyl groups present on the phenyl ring are involved in intermolecular H-bonding, which results in the stacking of molecules in the anti-parallel fashion leading an interesting network of channels. Besides this C–H⋯π and π–π (edge to edge) interactions appear to provide stability to the crystal lattice.     

Synthesis, Characterization and Antibacterial Activity of Schiff Base Derived from S-Methyldithiocarbazate and Methylisatin

Abstract  

New tridentate nitrogen–oxygen–sulfur Schiff base has been prepared from the condensation reaction of S-methyldithiocarbazate and methylisatin. The compound crystallized in triclinic crystal system with space group P − 1, Z = 2, V = 612.92(3) ?³ and unit cell parameters a = 6.8540(2) ?, b = 8.3022(2) ?, c = 11.5243(4) ?, α  = 79.8186(13)°,  β = 90.5224(14)° and  γ = 72.1362(13)°. Crystal structure reveals that the compound exists in the thione form with the methylisatin moiety is trans with respect to the C3–N2 and C3–S4 bonds whereas the methyl group of the dithiocarbazate moiety is cis with respect to the C3–N2 and C3–S5 bonds. The Schiff base was found to be selectively active against the selected Gram positive bacterial strains (Bacillus subtilis and Staphylococcus aureus) with the inhibition zones of 16 and 12 mm, respectively.     

Structural,Spectroscopic and Thermal Analysis of Cocrystals of Carbamazepine and Piracetam with Hydroquinone

Abstract  

Cocrystals of two important active pharmaceutical ingredients, carbamazepine and piracetam, with hydroquinone are reported. Cocrystal formation between the selected APIs and hydroquinone is investigated with the aid of solid-state grinding methods. Both the crystal structures belong to the triclinic, P [`1]P \bar{1} space group, with the cocrystal involving carbamazepine and hydroquinone having the unit cell parameters a = 6.9725 (14) ?, b = 8.8175 (18) ?, c = 15.083 (3) ?, α = 106.96 (3)°, β = 92.16 (3)°, γ = 103.23 (3)°, V = 858.0 (4) ?³ and Z = 2; and the cocrystal involving piracetam and hydroquinone has the unit cell parameters a = 6.4909 (13) ?, b = 6.5410 (13) ?, c = 11.612 (2) ?, α = 103.92 (3)°, β = 104.53 (3)°, γ = 91.06 (3)°, V = 461.59 (18) ?³ and Z = 2. Analysis of the cocrystals revealed that they are sustained by an alcohol–carboxamide heterosynthon. In addition, the cocrystal of carbamazepine and hydroquinone features an amide–alcohol heterosynthon and an alcohol–alcohol homosynthon. The cocrystal of piracetam and hydroquinone features an amide–amide dimer synthon. Cocrystal formation was evidenced from the shifts in the vibrational frequencies corresponding to the functional groups present on the cocrystal components.     

The Zolmitriptan-Pyridine (1:1) and Zolmitriptan-Propiophenone (3:2) Inclusion Complex

Abstract  

The crystal structures of zolmitriptan with pyridine (I) and propiophenone (II) solvates have been determined by single crystal X-ray diffraction studies. Compound (I) crystallizes in the orthorhombic space group P2₁2₁2₁ with a = 8.5610(5) ?, b = 12.2709(7) ?, c = 19.6201(12) ?, V = 2061.1(2) ?³, and Z = 4, while compound (II) crystallizes in the monoclinic space group P2₁ with a = 15.085(1) ?, b = 19.656(12) ?, c = 21.0860(13) ?, β = 92.068(1)°, V = 6248(4) ?³ and Z = 4. The asymmetric unit of (I), C₁₆H₂₁N₃O₂·C₅H₅N, contains one zolmitriptan molecule and one pyridine solvate, while the asymmetric unit of (II), 3(C₁₆H₂₁N₃O₂)·2(C₉H₁₀O) comprises six zolmitriptan molecules and four propiophenone solvates. In both structures, the N–H···N hydrogen bonds, form an infinite helical chain and generate a C(11)-type motif in (I) and a D₂²(13)-type motif in (II). Both the complexes have layer structures, the layers being constructed from rings (cavity) of four zolmitriptan molecules, hydrogen bonded through N–H···N and N–H···O bonds, where the pyridine (I) and propiophenone (II) solvates are included in an R₄⁴(33) ring.