Molecular and crystal structures of 2,4,6-trinitro-N-methyl-N-nitroaniline

The structure of single crystals of 2,4,6-trinitro-N-methyl-N-nitroaniline C₇H₅N₅O₈ (I) is determined by X-ray diffraction analysis. The unit cell parameters are a = 14.137(3) Å, b = 10.621(2) Å, c = 7.376(2) Å, γ = 95.19 (5)°, space group P2₁/b, and Z = 4. The structure is solved by the direct method and refined in the anisotropic approximation to R = 0.051 for 1917 reflections with I > 2σ(I). All hydrogen atoms are located and refined in the isotropic approximation. The carbon skeleton of the aromatic nucleus of the molecule tends to adopt the C(2),C(5)-boat conformation. The angle of rotation of the planar NNO₂ group with respect to the plane of the six-membered ring is 123.1(2)°. The NO₂groups that are bonded to the aromatic nucleus of the molecule are also rotated relative to this plane.     

Synthesis and structure of zinc iodide complex with thiocarbamide, [Zn(CH4N2S)2I2]

A complex compound of zinc iodide with thiocarbamide [Zn(CH₄N₂S)₂I₂] is obtained and its structure is studied by X-ray diffraction. Crystals are monoclinic, a = 10.494(2) Å, b = 7.473(2) Å, c = 14.871(4) Å, β = 91.354(18)°, V = 1165.9(5) ų, space group P2₁/c, Z = 4. The structural unit of the crystal is molecular complex [Zn(CH₄N₂S)₂I₂], in which the zinc atom is coordinated by sulfur atoms of two thiocarbamide molecules and two iodine atoms.     

Crystal structure of (Z)-1-(sec-butyl)-3-(4-dimethylaminophenyl)-2-(1H-1,2,4-triazol-1-yl)propen-2-one

The crystal structure of the title compound is determined by X-ray diffraction studies. The structure is solved by the direct method. The experimental data are obtained on a DAR-UMB diffractometer by the θ-θ/2θ scan technique using MoK _α radiation. The crystal is monoclinic, a = 17.913(3) Å, b = 17.239(3) Å, c = 5.501(5) Å, γ = 74.4(3)°, space group P2₁/a, Z = 4 for C₁₇H₂₂N₄O, and ρ_calcd = 1.211 g/cm³. The molecule consists of the phenyl and triazole rings and the dimethylamino, carbonyl, and isopropyl groups attached to the rings. The dihedral angle between the rings is 67.4°. The carbonyl oxygen atom and the triazole ring are in the trans position relative to each other. The N-C-C-O torsion angle is 172.8°. The molecule is in the Z isomeric form.     

Crystal and molecular structures of 2′-nitro-4-aminobiphenyl and 2-amino-7-nitrofluorene

2′-nitro-4-aminobiphenyl (5), C₁₂H₁₀N₂O₂, crystallizes in the monoclinic space groupP2₁/c:a = 6.043(2),b =15.795(3),c = 11.577(2) Å, β = 103.42(8) °;D _c = 1.324 g cm^?3 forZ = 4. 2-amino-7-nitrofluorene (3), C₁₃H₁₀N₂O₂, crystallizes in the monoclinic space groupP2₁ n:a = 10.765(2),b = 7.454(4),c = 12.959(2) Å, β = 95.44(1) °;D _c = 1.451 g cm^?3 forZ = 4. Three-dimensional CuKα intensity data were measured with a computer-controlled diffractometer, and the initial phases were obtained by direct methods. The two structures were refined by the full-matrix least-squares method, which gave finalR values for 5 and 3 of 0.045 and 0.043, respectively. Bond lengths in the compounds are normal, apart from slight shortening of the phenyl-phenyl C-C bond and some distortion of the phenyl rings caused by the amino and nitro groups. In 5, the two phenyl rings are twisted by 57.1 °, and the nitro group is twisted by 34.6 ° from the plane of its phenyl group. The carbon backbone of 3 is nearly planar with the two phenyl groups tilted by 4.0 ° to each other. The nitro group in 3 is twisted 5.7 ° from the plane of its phenyl group. There is amino hydrogen to nitro oxygen intermolecular hydrogen bonding in each structure.     

Synthesis and crystal structure of 2-propyl-5-phenyl-1, 4-dioxo-1,2,3,4,5,6,7,8-octahydro-[1,4,2]diazaphosphorino [1,2-a][1,3,2]benzodiazaphosphorine 3-oxide

The synthesis and structure characterization of 2-propyl-5-phenyl-1,4-dioxo-1,2,3,4,5, 6,7,8-octahydro-[1,4,2]diazaphosphorino[1,2-a][1,3,2]benzodiazaphosphorine 3-oxide are described. The title compound has been designed to incorporate proximate carbonyl and phosphoryl groups in a heterocycle fused to benzophosphadiamide heterocycle. Crystal data: C₁₉H₂₀N₃O₃P, Monoclinic, space group P2(1)/c, with a = 9.7585(9) Å, b = 21.4319(19) Å, c = 17.7900(16) Å, β = 100.823(2)°, Z = 8, V = 3654.5(6) ų. The crystal structure shows that the proximate carbonyl and phosphoryl groups are not coplanar, and the [1,4,2]diazaphosphorino moiety prefers the boat conformation.     

Crystal of catena-(μ2-terephthalato)-bis (N-methylimidazole)-copper(II)

A new one-dimensional chain complex [Cu(ta) (N-MeIm)₂]n (where ta = terephthalic acid dianion,N-MeIm =N-methylimidazole) has been synthesized and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes in the Monoclinic space groupP2₁/c with the parameters:a = 5.2930(11)Å,b = 14.679(3)Å,c = 11.007(3)Å, β = 104.84(3)^°,V = 826.7(3)ų, withZ = 4 formula units. In the structure, each Cu atom is coordinated by a pair ofN-methylimidazole ligands and a pair of monodentate carboxylate groups, affording a square planar N₂O₂ geometry. Both carboxylate groups of the terephthalate dianion coordinate in a monodentate mode bridging two Cu(II) ions with formation of 1D zigzag chain along thec axis. This supramolecular compound exhibits a three-dimensional solid state structure constituted by hydrogen bonds and C–H–π stacking interactions.     

Crystal structure of 5-(2′-aminophenyl)-2-dimethylamino-1,3,4-thiadiazole

The crystal structure of 5-(2′-Aminophenyl)-2-dimethylamino-1,3,4-thiazole is determined by X-ray diffraction. The compound is prepared by an unusual recyclization of 3-N, N-dimethylthioureidoquinazolin-4(3H)-one. The crystal is monoclinic, space group P2₁/c, a = 7.420(2) Å, b = 10.466(5) Å, c = 14.752(9) Å, β = 109.2(4)°, ρ_calcd = 1.359 g/cm³, and Z = 4 for the C₁₀H₁₂N₄S composition. The molecule consists of the thiadiazole and phenyl rings and the dimethylamine N(CH₃)₂ and amine NH₂ groups attached to the rings. The molecule as a whole is planar. The dihedral angle between the rings is 8.9°. The N(1) and N(4) atoms in the molecule are bound through the intramolecular interaction (2.76 Å). Molecules, which are linked in pairs by antiparallel hydrogen bonds, form a framework structure.     

Mathematical simulation and X-ray diffraction investigation of the crystal structure of (R)-[(R)-o-(1-N,N-dimethylaminoethyl)phenyl]-2,5-dimethoxyphenyl(phenyl)methanol

The crystal structure of (R)-[(R)-o-(1-N,N-dimethylaminoethyl)phenyl]-2,5-dimethoxyphenyl(phenyl)methanol is mathematically simulated by the discrete modeling of molecular packings. A complete set of possible model variants is analyzed using the proposed algorithm with the aim of choosing the appropriate models that can serve as starting models for solving and refining the crystal structure from X-ray diffraction data. The crystals of the compound under investigation are monoclinic, a = 9.268(2) Å, b = 8.802(2) Å, c = 13.176(3) Å, β = 94.01(3)°, space group P2₁, and Z = 2. The structure is solved for a starting model calculated using the discrete modeling method and refined by the full-matrix least-squares procedure to R(F) = 0.037 and ωR(F ²) = 0.097.     

Electron effects of the substituents on the structure of 4,4′-dipyridylium dications

The crystal structure of N,N′-di(2-hydroxyethyl)-4,4′-dipyridylium diperchlorate C₁₄H₁₈Cl₂N₂O₁₀ is determined by X-ray diffraction at 293 K. The crystals are monoclinic, a = 6.446(1) Å, b = 14.479(3) Å, c = 9.912(1) Å, β = 99.24(2)°, space group P2₁/c, and Z = 2; 1562 reflections measured; and wR2 = 0.086 and R1 = 0.033 for 1209 reflections with F > 4σ(F). It is found that, in the absence of charge transfer from the counterion to the dication, the planarity of the dipyridylium skeleton of the molecule is primarily due to the conjugation between the lone electron pairs of the hydroxyl groups and the π system of the dication. This inference is supported by the intramolecular O?N contact (2.847 Å).     

Crystal and molecular structure of the membrane-active antibiotic enniatin C

The crystal structure of the cyclic hexadepsipeptide antibiotic enniatin C c[-(L-MeLeu-D-Hyi)₃-], C₃₄H₅₉N₃O₉, was established by X-ray structure analysis (sp. gr. P2₁, a = 20.205(5) Å, b = 8.702(2) Å, c = 25.587(6) Å, γ = 97.0(5)°, V = 4465.3(18) ų, Z = 4, R = 0.089 for 3601 reflections with I > 2σ(I)). The unit cell contains two independent molecules of enniatin C, one ethanol molecule disordered over two positions, and approximately two water molecules occupying four positions and forming hydrogen bonds with each other. The independent antibiotic molecules adopt virtually identical conformations similar to those observed in the structures of enniatin B and its Na,Ni-complex. These conformations are characterized by alternating upward and downward orientations of the carbonyl groups and pseudoequatorial orientations of side radicals. The Leu residues have stretched conformations. The N-methylamide groups of the independent antibiotic molecules face each other, whereas the molecules are displaced by approximately 8.4 Å with respect to each other along the mean planes of the rings.     

Crystal structure of [N-(2-carbamoylethyl)iminodiacetato]-aqua(1,10-phenanthroline)cobalt(III) chloride 3.5 hydrate

The crystal structure of [N-(2-carbamoylethyl)iminodiacetato]-aqua(1,10-phenanthroline) cobalt(III) chloride 3.5 hydrate [Co(Ceida)(H₂O)(Phen)Cl · 3.5H₂O (I) has been determined by ¹H NMR technique and X-ray diffraction analysis. The crystals are triclinic, a = 10.352(2) Å, b = 12.534(3) Å, c = 20.665(4) Å, α = 107.02(3)°, β = 92.22(3)°, γ = 111.63(3)°, Z = 4, space group $P\bar 1$ , andR = 0.0438. The unit cell involves two crystallographically nonequivalent but virtually identical cationic complexes [Co(Ceida)(H₂O)(Phen)]⁺. The tridentate chelate ligand Ceida ^2? (N + 2O) occupies the face in the coordination octahedron of the Co atom, and the propionamide group remains free. The mean bond lengths are as follows: Co-O_Ceida, 1.876 Å; Co-N_Ceida, 1.981 Å; Co-N_Phen, 1.945 Å; and Co-O_w, 1.915 Å. In the structure, the arrangement of cationic complexes and certain water molecules exhibits a pseudosymmetry (the 2₁ axis). The cations and water molecules are located in the layers, and the anions are arranged between the layers. The structural elements are linked by hydrogen bonds and van der Waals interactions.     

X-ray mapping in heterocyclic design: VII. Diffraction study of the structure of N-pyridoneacetic acid and the product of its intramolecular dehydration

The structure of pyridoneacetic acid C₇H₇N₁O₃(I) is determined by the single-crystal X-ray diffraction technique. The crystals of I are monoclinic, a = 7.4502(15) Å, b = 10.006(6) Å, c = 9.960(3) Å, β = 109.96(2)°, Z = 4, and space group P2₁/c. The structure of pyridoneacetic acid is solved by the direct method and refined by the least-squares procedure in the anisotropic approximation to R = 0.0387. The structure of the product of its intramolecular dehydration, C₇H₆N₁O₂B₁F₄(II), is determined by the grid search procedure and refined by the Reitveld method (R _p = 0.045, R _wp = 0.58, R _e = 0.026, and χ² = 4.69). The crystals of II are monoclinic, a = 10.4979(3) Å, b = 11.4467(3) Å, c = 7.6027(1) Å, β = 100.83(2)°, Z = 4, and space group P2₁/n. The system of two conjugated heterocycles is planar.     

Synthesis and crystal structure of bis[2-[N-(2-chlorophenyl)formimidayl]-1-naphtholato]-(6Cl)copper(II)

The title compound, bis[2-[N-(2-chlorophenyl)formimidayl]-1-naphtholato]-(6Cl) copper(II), [Cu(C₁₇H₁₁NOCl)₂] (1) was synthesized and its crystal structure was determined. The Compound 1 is monoclinic, space group P2 ₁/c with a = 9.146(3) Å, b = 18.724(3) Å, c = 16.230(2) Å, β = 96.46(1)°, V = 2761.8(11) ų, Z = 4, D _c = 1.503 g cm^?3, μ(Mo Kα) = 1.020 mm^?1, R = 0.0606 for 2361 reflections [I > 2σ(I)]. In the title compound, the Cu atom is coordinated by an N₂O₂ donor set from the imine-phenol ligand in a slightly distorted square planar coordination geometry, with the two phenolate O atoms being deprotonated. The Cu–O bond lengths are 1.878(4) and 1.889(4) Å, the Cu–N bond lengths are 1.980(5) and 1.985(5) Å. The angles O1–Cu–N1 and O2–Cu–N2 are 90.96(19) and 90.72(19)°, respectively.     

Crystal Structure of Diethyl 2‐[2,2,2‐ trifluoro‐1‐(indole‐3‐yl)‐ethyl]‐2‐acetamidomalonate

The title compound (C₁₉H₂₁F₃N₂O₅) has been determined from three dimensional X‐ray diffraction data. The crystals are monoclinic, a = 7.626(4)Å, b = 17.515(4)Å, c = 15.066(3)Å, β = 101.02(3)°, V = 1975(1)ų, Z = 4, D_calc = 1.393g cm^‐3, space group P2₁/c. The structure was solved by direct methods and refined by full‐matrix least‐squares method (R = 0.039).     

X-ray mapping in heterocyclic design: XI. X-ray diffraction study of 1-benzoyl-3-(pyridin-2-yl)-thiocarbamide and the product of its reaction with oxidants

The structures of 1-benzoyl-3-(pyridin-2-yl)-thiocarbamide C₁₃H₁₁N₃O₁S₁ (I) and 2-benzoylimino-1,2,4-thiadiazole[2,3-a]pyridine C₁₃H₉N₃O₁S₁ (II) are studied by X-ray diffraction. Structures I [a = 5.342(4) Å, b = 20.428(5) Å, c = 11.784(4) Å, β = 90.55(2)°, Z = 4, space group P2₁/n) and II [a = 6.258(6) Å, b = 18.068(14) Å, c = 10.185(10) tA, β = 95.45(8)°, Z = 4, space group P2₁/n) are determined by direct methods and refined to R ₁ = 0.0673 and 0.0802, respectively. In structure I, both intramolecular (involving the O atom) and intermolecular (involving the N and S atoms) hydrogen bonds are observed. The latter bonds are responsible for the formation of centrosymmetric molecular dimers. In structure II, a short intramolecular contact (2.168 Å) is observed between the S and O atoms.     

Synthesis,Crystal Structure,and Free Radical Scavenging Activity of 4-Aminopyridinium 3,5-Dinitrobenzoate

The crystal structure of 4-aminopyridinium 3,5-dinitrobenzoate, C₁₂H₁₀O₆N₄, has been determined by single-crystal X-ray diffraction technique. The title compound crystallizes in the monoclinic sp. gr. P21/n with the unit cell parameters: a = 7.4726(3) Å, b = 23.0898(9) Å, c = 8.0744(4) Å, V = 1338.64(10) ų, Z = 4. The asymmetric unit of the compound consists of one 3,5-dinitrobenzoate anion and 4-aminopyridine cation. The adjacent anions and cations are linked through two N?H···O hydrogen bonds, N2?H2A···O5 and N₂?H2B···O6, to form an infinite chain of anions and cations, extended along the [010] direction.     

The electronic nature of the substituents and the structure of 4,4′-dipyridilium dications. The crystal structure of N,N′-di(carbethoxymethyl)-4,4′-dipyridilium diperchlorate

The crystal structure of N,N′-di(carbethoxymethyl)-4,4′-dipyridilium diperchlorate (I) C₁₈H₂₂Cl₂N₂O₁₂ at 293 K is determined by the X-ray diffraction technique. The crystals are monoclinic, a = 5.501(1) Å, b = 26.460(5) Å, c = 8.140(2) Å, β = 100.63(3)°, space group P2₁/n, Z = 2, 2271 reflections measured (2052 reflections unique), R ₁ = 0.062, and wR2 = 0.141 for 1161 reflections with F ≥ 4σ(F). The interaction between the lone-electron pair of the carbonyl oxygen atom of the electron-withdrawing ester group and the π system of the dication manifests itself as the intramolecular O(1)?N contact (2.780 Å). In the absence of charge transfer from the counterion to the dication, this interaction contributes to the stabilization of a planar structure of the dication fragment of the molecule despite the electron-withdrawing nature of the ester groups.     

Disaccharide nucleosides: The crystal and molecular structure of 2′-<Emphasis Type="Italic">O</Emphasis>-β-<Emphasis Type="Italic">D</Emphasis>-ribopyranosylcytidine

The crystal structure of a disaccharide nucleoside, 2′-O-β-D-ribopyranosylcytidine, is studied using X-ray diffraction (space group P2₁, a = 6.827(2) Å, b = 12.813(3) Å, c = 9.532(2) Å, β = 92.934(5)°, V = 832.7(4) ų, Z = 2). The stereochemical features of the molecular structure of 2′-O-β-D-ribopyranosylcytidine are analyzed, and the structural data are compared with those obtained for the previously studied disaccharide nucleoside 2′-O-β-D-ribofuranosyluridine.     

X-ray mapping in heterocyclic design: IX. X-ray structure investigation of conjugated aminodienes

The single-crystal structures of two aminodienes containing an oxazole fragment, namely, 1-pip-eridyl-4-[5-(4-nitrophenyl)-oxazol-2-yl]-buta-1,3-diene C 18 H 19 N 3 O 3 (IIa) and 1-hexamethyleneimine-4-[5-(4-nitrophenyl)-oxazol-2-yl]-buta-1,3-diene C₁₉H₂₁N₃O₃ (IIb), are studied by X-ray diffraction. Structures IIa [a = 16.181(6) Å, b = 5.939(3) Å, c = 17.337(9) Å, β = 96.13(2)°, Z = 4, and space group P2₁] and IIb [a = 7.4704(11) Å, b = 10.9904(19) Å, c = 43.434(6) Å, β = 91.24(1)°, Z = 8, and space group P2₁/_c] are solved by the direct method and refined to R = 0.060 and 0.238, respectively. Although the ring sizes of the cyclic amines in compounds IIa and IIb are different, the designs of two structures are identical. Each structure contains two topologically identical but crystallographically independent molecules. In structure IIa, the intramolecular hydrogen bonds between the N atoms of the oxazole fragments and the H atoms of the diene fragments are formed. In structure IIb, similar bonds are absent.     

Isomerization of 2-seleno-1,3,2-diazaphospholidine derivatives

For the first time the isomerization of 1,3,2-diazaphospholidine-2-selenide derivatives in refluxing benzene in the presence of trace water was observed, and the structure of isomerized product was determined by X-ray diffraction, IR, ¹H NMR, ³¹P NMR, and elemental analysis. The mechanism of isomerization was also proposed. The isomerized phosphoroheterocycle (C₂₆H₃₈N₃O₅PSe, Mr = 582.52) is orthorhombic with space group Pbca, a = 17.1010(9) Å, b = 16.6404(9) Å, c = 20.7517(11) Å, V = 5905.3(5) ų, Z = 8, Dr = 1.310 g/cm³, λ = 0.71073 Å, μ (Mo Kα) = 1.363 mm^?1, F(000) = 2432. The structure was refined to R1 = 0.0482, wR2 = 0.1204 for 5214 unique reflections with I > 2σ(I). Intramolecular and intermolecular hydrogen bonds are observed in the crystal packing.