Synthesis of <Emphasis Type="Italic">E</Emphasis> Isomer and Crystal Structures of <Emphasis Type="Italic">E</Emphasis> and <Emphasis Type="Italic">Z</Emphasis> Isomers of 3-(2,5-Dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile

Abstract Details of the synthesis of the E isomer of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile, and the X-ray crystal structures of both the E and Z isomers of this compound are presented. The E isomer crystallizes in the P2₁/c space group with cell parameters, a = 8.5659(17) ?, b = 16.399(3) ?, c = 11.224(2) ?, α = 90°, β = 95.27(3)°, γ = 90°and Z = 4. The Z isomer crystallizes in the Pca2₁ space group with cell parameters, a = 4.1223(8) ?, b = 19.113(4) ?, c = 19.453(4) ?, α = 90°, β = 90°, γ = 90° and Z = 4. Index Abstract Synthesis of E isomer and X-ray crystal structure determination of both E and Z isomers of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylonitrile are presented.      

An X-ray Crystallographic Study of 1,4-Di[(<Emphasis Type="Italic">E</Emphasis>)-2-(<Emphasis Type="Italic">p</Emphasis>-tolyl)-1-diazenyl]piperazine

Abstract  

The crystal structure of methyl 1,4-di[(E)-2-(p-tolyl)-1-diazenyl]piperazine (4) has been determined by single crystal X-ray diffraction analysis. The bis-triazene (4) adopts a normal chair conformation in the piperazine ring, with puckering parameters : φ₂ = −29(5)°, Q_T = 0.534(2) ? and θ₂ = 177.0(2)°. The crystal structure of 4 is compared with the structure of the triazene (2a) and the closely related bis-triazenes (3 and 5a). The piperazine ring of 2a and 4 adopt a typical chair conformation, whereas the piperazine ring of 3 adopts an unusual pseudo-boat conformation. Crystal data: 4 C₁₈H₂₂N₆, triclinic, space group P[`1] P\overline{1} , a = 6.8925(2) ?, b = 7.8574(3) ?, c = 16.8856(8) ?, α = 103.103(2)°, β = 90.528(2)°, γ = 101.776(2)° and V = 870.44 (6) ?³, for Z = 2.     

Crystal Structure and Conformational Analysis of 4-[(<Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-Dimethylamino)Benzylidene]-2-Phenyloxazole-5-One

Abstract  

Molecular and crystal structure of 4-[(p-N,N-dimethylamino)benzylidene]-2-phenyloxazol-5-one, C₁₈H₁₆N₂O₂, have been determined by single crystal X-ray diffraction study. The title compound is monoclinic, with a = 12.1704(23) ?, b = 3.9810(5) ?, c = 30.9603(56) ?, β = 101.176(15)°, Z = 4, D _x = 1.32 g/cm³, μ(Mo Kα) = 0.087 mm⁻¹, and space group is P12₁/c1. The structure was solved by direct methods and refined to a final R = 0.047 for 3166 reflections with I > 2σ(I). The crystal structure is stabilized by C–H⋯O and C–H⋯N type intra-molecular, C–H⋯O type inter-molecular interactions. To enlighten the flexibility and the geometric isomerism (E or Z) of the title compound, the selected torsion angle is varied from −180 to 180° in every 10° separately and molecular energy profile is calculated and analyzed.     

Synthesis and Crystal Structures of <Emphasis Type="Italic">o</Emphasis>-[(Phenyl/<Emphasis Type="Italic">p</Emphasis>-methoxyphenyl)carbamoyl]benzene Sulfonamides

Abstract  

o-[(Phenyl/p-methoxyphenyl)carbamoyl]benzene sulfonamides were synthesized in a straightforward manner utilizing directly saccharin and aniline/p-anisidine as starting material and their crystal structures have been determined. (C₁₃H₁₂N₂O₃S): Mr = 276.31, monoclinic, P2₁/c, a = 10.277(6), b = 7.501(2), c = 16.261(10) ?, β = 96.37(2)°, V = 1,245.8(11) ?³, Z = 4. (C₁₄ H₁₄ N₂ O₄ S): Mr = 306.33, monoclinic, P2₁/c, a = 10.381(5), b = 7.861(2), c = 16.837(9) ?, β = 93.43(2)°, V = 1,371.5(10) ?³, Z = 4. In both structures the phenyl rings are inclined at 47.09(7) and 39.88(5)° with respect to each other and the structures are characterized by extensive inter and intramolecular hydrogen bonds.     

Synthesis and structure of 7-methyl-5-phenyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazolo[4,3-<Emphasis Type="Italic">e</Emphasis>]tetrazolo[4,5-<Emphasis Type="Italic">b</Emphasis>][1,2,4]triazine<Superscript>(1)</Superscript>

The synthesis of 5-azido-3-methyl-1-phenyl-1H-pyrazolo[4,3-e][1,2,4]triazine 2 and 7-methyl-5-phenyl-1H-pyrazolo[4,3-e]tetrazolo[4,5-b][1,2,4]triazine 3 is described and the crystal and molecular structure of the latter is reported. This compound crystallizes in the monoclinic system, space group P2₁/n, with cell constants a = 11.607(2) Å, b = 7.982(1) Å, c = 13.147(2) Å, = 110.60(1), Z = 4, T = 293 K and D_cal = 1.470 g cm^–3. The structure was solved by direct methods and refined to R value of 0.0368 for 1906 reflections. The X-ray analysis revealed that the linear form of the tetrazolo-fused ring system of 3 exists in the crystal. The molecule as a whole has an almost planar conformation stabilized by the short intramolecular NsH interaction. The molecular packing in the crystal is determined by the van der Waals forces only.Part 26 in 1,2,4-triazines in organic synthesis. For part 25 see Mojzych et al.¹     

Synthesis and Crystal Structure of (5-Methyl-3-phenyl-1<Emphasis Type="Italic">H</Emphasis>-pyrazol-1-yl)-[5-(<Emphasis Type="Italic">p</Emphasis>-tolylamino)-2<Emphasis Type="Italic">H</Emphasis>-1,2,3-triazol-4-yl]methanone

Abstract  

(5-Methyl-3-phenyl-1H-pyrazol-1-yl)-[5-(p-tolylamino)-2H-1,2,3-triazol-4-yl]methanone was synthesized and characterized by ¹H NMR, MS and IR spectra data. The structure of title compound was identified by X-ray diffraction. Compound, C₂₀H₁₈N₆O, Mr = 358.40, crystallizes in the triclinic space group P-1 with unit cell parameters a = 10.303(6), b = 12.489(7), c = 15.305(9) ?, α = 108.489(12), β = 101.920(11), γ = 96.971(13)°, V = 1790.0(17) ?³, Z = 4, Dx = 1.330 mg/cm³. The final R was 0.0520.     

Crystal structure of <Emphasis Type="Italic">p</Emphasis>-carboxyphenylhydrazone benzoylacetone

The crystal structure of p-carboxyphenylhydrazone benzoylacetone is determined. The crystals are monoclinic, a = 13.614(4) Å, b = 11.388(2) Å, c = 20.029(6) Å, β = 104.82(2)°, V = 2339(9) ų, Z = 8, space group C2/c, and R = 0.038 for 1622 reflections with I > 2σ(I). The crystal is built of C₁₇H₁₄N₂O₄ neutral molecules that are linked by O-H?O hydrogen bonds between the carboxyl groups into centrosymmetric pseudodimers. The effect of carboxylation of the phenylhydrazone fragment and the position of the carboxyl group on the molecular packing in the crystal is determined. The N(1)-H(1N)?O(1) intramolecular hydrogen bond (N-H, 0.94 Å; H?O, 1.87 Å; N?O, 2.59 Å; and the N-H?O angle, 133°) is formed in the molecule.     

Electron diffraction study of 1<Emphasis Type="Italic">M</Emphasis> illites with interstratified <Emphasis Type="Italic">trans</Emphasis>- and <Emphasis Type="Italic">cis</Emphasis>-vacant 2 : 1 layers

Illites from the volcanogenic Zn-Au-Ag sulfide deposit Galkinskoe (Northern Urals) have been investigated using oblique-texture electron diffraction patterns in combination with the simulation of diffraction effects. Along with single-phase tv/cv1M illites, the structures of which are formed by statistically interstratified dioctahedral 2: 1 layers with vacant trans- or cis-octahedra, illites in the form of a mixture of two interstratified tv/cv1M phases, with the dominance of tv- or cv layers, are identified. It is shown that in the latter case the diffraction pattern can also be interpreted within the single-phase tv/cv model, provided that the tv- and cv layers are distributed with some tendency to segregate. The structural features indicating the preference of the two-phase model are analyzed.     

Distribution of component molecules in <Emphasis Type="Italic">p</Emphasis>-dibromobenzene-<Emphasis Type="Italic">p</Emphasis>-dichlorobenzene solid solutions from raman effect data

Distribution of component molecules in the bulk of single crystals of p-dibromobenzene-p-dichlorobenzene solid solutions grown by the Bridgman method studied by Raman effect.     

A New <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-Dimethyl Purine from an Australian <Emphasis Type="Italic">Dictyoceratid Sponge</Emphasis>

Abstract  

N6-methyl mucronatine (C₈H₁₂N₅O) has been isolated from a dictyoceratid sponge collected in South East Queensland. The solid state structure of the new metabolite (I) was confirmed by X-ray crystallography, while an NMR study in d ₄-MeOH reveals the presence of a minor tautomer identified as (II).     

Synthesis,Separation and Crystal Structures of <Emphasis Type="Italic">E</Emphasis> and <Emphasis Type="Italic">Z</Emphasis> Isomers of 3-(2,5-Dimethoxyphenyl)-2-(4-Methoxyphenyl)Acrylic Acid

Abstract Synthesis, separation and X-ray crystal structures of E and Z isomers of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylic acid are reported. Separation of E and Z isomers from a 1:1 mixture has been carried out by selective acidification of their sodium salts carefully controlling the pH of the solution. The structures of E and Z isomers were confirmed by determining crystal structures of these isomers using single crystal X-ray diffraction. The E isomer crystallizes in the P2₁/c space group with a = 11.493(2) ?, b = 5.5456(11) ?, c = 24.900(5) ?, α = 90°, β = 92.36(3)°, γ = 90°, Z = 4. The Z isomer crystallizes in the P2₁/c space group with a = 10.192(2) ?, b = 12.893(3) ?, c = 13.948(3) ?, α = 90°, β = 92.18(3)°, γ = 90°, Z = 4. Details of the synthesis and structural characterization and X-ray crystal structure determination of the title compounds are presented. Index Abstract Synthesis, Separation and Crystal Structures of E and Z Isomers of 3-(2,5-Dimethoxyphenyl)-2-(4-Methoxyphenyl)Acrylic Acid Balachandra Chenna, Bidhan A. Shinkre, Shweta Patel, Samuel B. Owens Jr., Gary M. Gray, Sadanandan E. Velu* Separation of E and Z isomers of 3-(2,5-dimethoxyphenyl)-2-(4-methoxyphenyl)acrylic acid from a 1:1 mixture has been carried out by selective acidification of their sodium salts and the structures of the individual isomers have been determined by X-ray single crystal diffraction.      

Synthesis and structure of chiral ligand [(<Emphasis Type="Italic">S</Emphasis>)-1-(((<Emphasis Type="Italic">S</Emphasis>)-1-methylpyrrolidin-2-yl) methyl) pyrrolidin-2-yl] diphenylmethanol

The title compound (C₂₃H₃₀N₂O), a chiral ligand, has been successfully synthesized from a natural proline. FTIR spectrum has been discussed. DFT (B3LYP) method has been used to determine the structure. With the basis set of the 6–311G^* quality, the DFT calculated bond parameters and harmonic vibrations are predicted in very good agreement with experimental data.

Synthesis and crystal structure of mixed-ligand Cu(II) complex of <Emphasis Type="Italic">N</Emphasis>-(1-phenyl-3-methyl-4-benzylidene- 5-pyrazolone) <Emphasis Type="Italic">p</Emphasis>-nitrobezoylhydrazide and pyridine

A new mixed-ligand copper(II) complex, [Cu(PMBP-PNH)Py], (PMBP-PNH = N-(1-phenyl-3-methyl-4-benzylidene-5-pyrazolone) p-nitrobezoylhydrazide; Py = pyridine), has been synthesized by solvothermal method and characterized by elemental analysis, IR spectrum, thermal analysis and single crystal X-ray diffraction: monoclinic, space group Cc with a = 6.0422(8) Å, b = 22.796(3) Å, c = 18.353(3) Å, β = 93.199(3)^∘, Mr = 582.08, V = 2524.0(6) ų, Z = 4. The copper(II) ion in the title complex is in a slightly distorted square-planar arrangement of the ONO donor atoms of primary ligand PMBP-PNH and one N-donor atom in the secondary ligand pyridine.     

Synthesis,Characterization, Crystal Structure,and Hirshfeld Surface Analysis of Ethyl 2-(4-bromophenyl)-1-cyclohexyl-1<Emphasis Type="Italic">H</Emphasis>-benzo[<Emphasis Type="Italic">d</Emphasis>]imidazole-5-carboxylate

The title compound, C₂₂H₂₃N₂BrO₂ was synthesized via one-pot reductive cyclization method and characterized by CNH analysis, FT-IR, UV-visible, mass, ¹H and ¹³C NMR spectra, thermogravimetric analysis (TGA) and single crystal X-ray diffraction method. The compound crystallizes in monoclinic crystal system: sp. gr. P2₁/c, Z = 4. The crystal data reveals that the intermolecular interactions of the C–H···π and π···π type connect the molecules which was also visualized with the help of Hirshfeld surface analysis.     

Experimental and Semi-Empirical and DFT Calculational Studies on (<Emphasis Type="Italic">E</Emphasis>)-2-[(2,4-Dichlorophenylimino) methyl]-<Emphasis Type="Italic">p</Emphasis>-cresol

Abstract  

The molecular and crystal structure of the title compound, C₁₄H₁₁Cl₂NO, has been determined by X-ray single crystal diffraction technique. The compound crystallizes in the orthorhombic, space group Pbca with unit cell dimensions a = 7.5537(10) ?, b = 11.5518(13) ?, c = 29.760(4) ?, M _r  = 280.14, V = 2596.8(6) ?³, Z = 8, R ₁ = 0.065 and wR ₂ = 0.191. The title compound exists in the enol–imine tautomeric form with a strong intramolecular O–H···N hydrogen bond. The dihedral angle between the two benzene rings is 37.66(15)°. The asymmetric unit in the crystal structure contains only one neutral molecule. Calculational studies were performed by using AM1, PM3, PM6 semi-empirical and DFT methods. Geometry optimizations of compound have been carried out by using three semi-empirical methods and DFT method and bond lengths, bond and torsion angles of title compound have been determined. Dipole moments (Debye) and the energy parameters of compound (kcal/mol) were calculated by using above mentioned calculation methods. Atomic charge distribution has been obtained from AM1, PM3, PM6 and DFT. In order to determine conformational flexibility on the molecule, molecular energy profile of the title compound was obtained with respect to the selected torsion angle T(N1–C7–C1–C2), which is varied from −180° to +180° in every 10 via PM3 semi-empirical method.     

Synthesis and structural studies of <Emphasis Type="Italic">tris</Emphasis>-2-chlorobenzylamine and <Emphasis Type="Italic">tris</Emphasis>-2-bromobenzylamine

The tris-2-chloro and 2-bromotribenzylamines are prepared from aqueous ammonia and 2-chlorobenzyl chloride and 2-bromobenzyl bromide, respectively, in ethanol. Recrystallization yielded colorless cubes of each product. The crystal structures are each solved in space group P , and are isostructural. The tris-2-chloro compound, 1, has a = 7.4226(5) Å, b = 9.0825(7) Å, c = 14.529(1) Å, = 78.279(1), = 82.389(1), = 84.661(1), and V = 948.41(12) ų with Z = 2, and d_calc = 1.368 Mg/m³. The tris-2-bromo analog, 2, has a = 7.6569(11) Å, b = 9.0922(13) Å, c = 14.614(2) Å, = 79.286(2), = 81.777(2), = 85.401(2), and V = 987.9(2) ų with Z = 2, and d_calc = 1.762 Mg/m³. Lithium–halogen exchange experiments conducted in tetrahydrofuran at –78C using n-butyl lithium revealed that no exchange occurred for the tris-2-chloro compound, but did occur for the tris-2-bromo analog to yield tribenzylamine upon quench and work-up.     

Synthesis and X-ray structural analysis of (2<Emphasis Type="Italic">Z</Emphasis>)-3(4-hydroxyphenyl)-2-pyridin-4-ylacrylonitrile and (2<Emphasis Type="Italic">Z</Emphasis>)-3-(3,5-di-<Emphasis Type="Italic">tert</Emphasis>-butyl-4-hydroxyphenyl)2-pyridin-4-ylacrylonitrile

Synthesis and X-ray structural investigations have been carried out for the two title compounds C₁₄H₁₀N₂O (3a) and C₂₂H₂₆N₂O (3b). Compound 3a crystallizes in the monoclinic space group P2₁/c, with a = 3.843(1) Å, b = 24.618(5) Å, c = 11.318(2) Å, = 92.61(3), V = 1069.7(4) Å,³ and Z = 4. Compound 3b crystallizes in the triclinic space group P-1, with a = 9.004(2) Å, b = 9.447(2) Å, c = 11.713(2) Å, = 76.70(3), = 83.12(3), = 82.16(3), V = 956.5(3) Å,³ and Z = 2. Both stilbazole derivatives have Z-geometry about the ethylene bridge which links the heterocyclic and aromatic rings. The molecular skeleton of 3a is slightly non-planar: the dihedral angles between the acrylonitrile linkage and the pyridine ring, and between this linkage and the p-hydroxyphenyl ring are 7.2(2) and 4.1(2), respectively. The molecular skeleton of 3b is less planar: the values of similar dihedral angles are 17.0(2) and 20.8(2), respectively. In the crystal of 3a, the molecules are packed in stacks along the a axis with head-to-head orientation. Intermolecular hydrogen bonds O=H s N and C=H s N link molecules into sheets parallel to (100) plane. In the crystals of 3b, the molecules have a head-to-tail orientation and intermolecular hydrogen bonds O=H s N link the molecules into infinite chains along [01-1] direction.     

The Synthesis and Structure of Two Novel <Emphasis Type="Italic">N</Emphasis>-(Benzothiazol-2-yl)benzamides

Abstract  Two novel benzothiazoles 2-chloro-N-(benzothiazol-2-yl)benzamide (1) and 2-chloro-N-(6-cyanobenzothiazol-2-yl)benzamide (2) were obtained in multistep synthesis. They were characterised by means of IR, ¹H- and ¹³C-NMR spectroscopy and also by single-crystal X-ray diffraction. The compound 1 crystallises with triclinic space group P , a = 9.5923(8) ?, b = 9.8583(8) ?, c = 13.8962(10) ?, α = 89.162(6)°, β = 77.741(7)°, γ = 80.064(7)°, V = 1264.5(2) ?³, Z = 4 and compound 2 crystallises as methanol solvate with monoclinic space group P 2₁/n, a = 7.5093(9) ?, b = 13.0211(14) ?, c = 16.032(2) ?, β = 92.717(10)°, V = 1565.9(3) ?³, Z = 4. Both crystal structures consist of discrete dimers connected into a three-dimensional network by intermolecular C–H···O and C–H···X (X = Cl or S) hydrogen bonds and by face-to-face π–π stacking interactions. Index Abstract  The synthesis and structure of two novel N-(benzothiazol-2-yl)benzamides. Irena Ćaleta, Dominik Cinčić, GraceKarminski-Zamola and Branko Kaitner. Hydrogen bonds and π–π interactions in N-(benzothiazol-2-yl)benzamides N-(benzothiazol-2-yl)benzamides.      

X-ray crystal structures of two polymorphic forms,monoclinic and triclinic,of: 1-[(<Emphasis Type="Italic">E</Emphasis>)-2-(4-bromophenyl)1-diazenyl]-3-({3-[(<Emphasis Type="Italic">E</Emphasis>)-2-(4-bromophenyl)-1-diazenyl]-6-ethylhexahydro-1-pyrimidinyl}methyl)-4-ethylhexahydropyrimidine

1-[(E)-2-(4-bromophenyl)-1-diazenyl]-3-({3-[(E)-2-(4-bromophenyl)-1-diazenyl]-6-ethylhexahydro-1-pyrimidinyl}methyl)-4-ethylhexahydropyrimidine (1) has been synthesized by reaction of a mixture of formaldehyde and 1,3-pentanediamine{DYTEK^®EPdiamine} with p-bromobenzenediazonium chloride. This compound crystallizes in two polymorphic forms 1-α and 1-β whose crystal structures have been determined by single crystal X-ray diffraction analysis. Both polymorphs 1-α and 1-β display crystallographic disorder within the hexahydropyrimidine rings. The molecule of 1 is built up of two equivalent 3-(aryldiazenyl)-6-ethylhexahydro-1-pyrimidinyl groups in the s-trans orientation around the central methylene group (C13). In both structures the triazene moieties adopt the anti configuration around the N=N bonds, displaying significant π-conjugation. The crystal packings are determined only by van der Waals interactions. The crystal structures of 1-α and 1-β are compared with the previously reported structure of the 5,5-dimethylhexahydropyrimidine analogue 3. Compounds 1 and 3 are isomeric with respect to the hexahydropyrimidine moiety. The structures of 1 and 3 are very different in one respect; in 1 the aryldiazenyl-hexahydropyrimidinyl groups are in the s-trans orientation around the central methylene group, whereas in 3 the arrangement of the aryldiazenylhexahydropyrimidinyl groups is the s-cis orientation. Crystal data: 1-α C₂₅H₃₄N₈Br₂, monoclinic, space group P2(1)/c, a = 9.2150(3), b = 19.4059(6), c = 15.4324(5) Å, β = 98.738(1)^°, V = 2727.7(2) ų, for Z = 4; 1-β C₂₅H₃₄N₈Br₂, triclinic, space group P-1, a = 9.6009(3), b = 10.7509(4), c = 14.2169(5) Å, α = 99.830(2), β = 105.973(3), γ = 95.578(1)^°, V = 1373.9(1) ų, for Z = 2.     

Crystal Structure of Two <Emphasis Type="Italic">V</Emphasis>-shaped Ligands with <Emphasis Type="Italic">N</Emphasis>-Heterocycles

Two V-shaped ligands with N-heterocycles, bis(4-(1H-imidazol-1-yl) phenyl)methanone (1), and bis(4-(1H-benzo[d]imidazol-1-yl)phenyl)methanone (2) have been synthesized and characterized by elemental analyses, IR and 1H NMR spectroscopy. Crystal structures of 1 and 2 have been determined by X-ray diffraction. The crystal of 1 is monoclinic, sp. gr. P2₁/c, Z = 4. The crystal of 2 is orthorhombic, sp. gr. Fdd2, Z = 8. X-ray diffraction analyses show that the V-shaped angles of 1 and 2 are 122.72(15)° and 120.7(4)°, respectively. Intermolecular C–H···O, C–H···N, C–H···π, and π···π interactions link the components into three-dimensional networks in the crystal structures.