Crystal and molecular structures of 2-amino-5-(m-nitrophenyl)-1,3,4-Thiadiazole

2-Amino-5-(m-nitrophenyl)-1,3,4-thiadiazole (C₈H₆N₄O₂S) is studied using IR and ¹H NMR spectroscopy and X-ray diffraction (CAD4 automated diffractometer, λMoK _α, graphite monochromator, 957 unique reflections, Patterson method, R = 0.0326). The crystals are monoclinic, a = 11.832 Å, b = 9.862 Å, c = 8.353 Å, β = 110.40(3)°, V = 913.6(3) ų, d _calcd = 1.212 g cm^?3, μ(MoK _α) = 0.253 mm^?1, Z = 4, and space group P2₁/c. In the crystal, the C₈H₆N₄O₂S molecules form infinite layers parallel to the xz plane. Each layer contains aromatic rings with nitro groups that deviate from the layer plane on either side of the layer. In the packing, the aromatic rings with nitro groups of one layer fill spaces between aromatic rings with nitro groups of the adjacent layers.     

Crystal and molecular structures of two polymorphs of 4-methyl-2-nitroacetanilide (MNA)

Journal of Chemical Crystallography - The crystal and molecular structure of white (MNA-1) and yellow (MNA-3) forms of 4-methyl-2-nitroacetanilide have been determined by X-ray diffraction...     

Crystal and molecular structure of (2-amino-4-methyl-1-pyridinio) cyanoborane

The crystal structure of the title compound, C₇H₁₀N₃B, has been determined by X-ray diffraction using CuK radiation. The crystals are monoclinic,P2₁/c witha=6.941(2),b=15.961(3),c=7.739(2) Å,=90.5(2)° andZ=4. The structure was solved by direct methods, and refined by full matrix least squares to a finalR-value of 056 with 833 observed reflections. The molecule is in the elongated form, but is not planar; the torsion angle C(2)-N(1)-B-C(8) is 82.9(4)°. The bond distances N(1)-B=1.587(5) Å; B-C(8)=1.586(6) Å; C(8)N(3)=1.134(5) Å. The B-C-N moiety is slightly [176.9(4)°] nonlinear. The molecules are linked by weak hydrogen bonds N(2)-H(1N)N(3), N(2)-N(3)=3.055(5) Å and N(2)-H(2N)N(3), N(2)-N(3)=3.165 Å.     

Crystal structures of two isomeric oximes. (EE)-2-methyl-3-phenyl-3-thiocyanatopropenaldoxime and (Z)-5-methyl-6-phenyl-1,3-thiazin-2-one oxime

The crystal structure of two isomeric oximes, C₁₁N₁₀N₂OS have been studied by X-ray diffraction. The open-chain thiocyanato derivative is somewhat'less dense and crystallizes with the orthorhombic space group Pbcn;a,b,c=18.718(1), 10.601(3), 11.528(1) Å,Z=8. The heterocyclic isomer occurs as pseudo-orthorhombic (Cmma)twinned crystals of space group P2₁/n, a, b, c, =12.11(1), 7.46(1), 12.12(1) Å, 100.09(1)^o,Z=4. Twinning occurs as a result of the near-equality of the monoclinica andc cell constants.     

Crystal and molecular structure of 1-(p-bromobenzoyl)-2-methyl-1,2,3,4-tetrahydroquinoline

Crystals of the title compound, C₁₇H₁₆BrNO, are monoclinic, space groupP2₁/n, unit-cell parametersa = 14.48,b = 6.20,c = 16.72 Å, and = 97.35 °. Three-dimensional data were collected with CuK radiation using an automatic diffractometer. The structure was solved by the heavy-atom method and refined by block diagonal least squares to anR index of 0.088 for 2210 reflections. The main features obtained from our studies are (i) the C=O group is orientedanti to the benzene ring, in agreement with the nmr studies; (ii) the C(2) proton is equatorial while the methyl group at C(2) is in an axial position, also in agreement with nmr data. The bromobenzoyl ring and the benzene ring are at 64 ° to each other, while the carbonyl >C=O and the bromobenzoyl groupsBr are at 42 ° to each other.     

Crystal and molecular structure of an amber polymorph of 4-methyl-2-nitroacetanilide (MNA)

The crystal and molecular structure of a third polymorph of 4-methyl-2-nitroacetanilide has been determined by X-ray diffraction. It crystallizes in the monoclinic system, space groupP2₁/c,Z=4,a=10.158(2),b=11.635(2),c=8.041(2) Å and=94.55(2)°. Using 1027 unique reflections, the structure was solved by the method of vector verification and refined by full-matrix least squares, which gave convergence toR=0.080. The structure consists of nearly planar molecules, all approximately parallel to one another with their longitudinal axes parallel tob. The amide group forms an intramolecular hydrogen bond with the nitro group. Molecules related byc-glide are stacked alongc in a very distinct columnar form. The columns are held together by dipole-dipole interactions between close antiparallel carbonyl groups or between close antiparallel nitro groups.     

Crystal and molecular structure of p-chlorothymols. II: 4-chloro-3-methyl-5-isopropylphenol (PCMT)

The crystal and molecular structure of the title compound: C₁₀H₁₃OCl, determined by single-crystal X-ray diffraction is reported. Crystals are monoclinic, space group P2₁/a (N_o14),a=18.435(7),b=24.642(6),c=9.116(6)Å,=103.23(5)°,Z=16,D _x =1.216 Mg m^–3,F(000)=1568,V=4031(1)ų. The structure was solved by direct methods and the finalR value is 8.5%. The four molecules in asymmetric unit are linked by hydrogen bonds and form an infinite chain parallel to the (bc) plane. Different chains are held together by van der Waals forces.     

Crystal structures of two azo compounds, 2-methyl-2-(4-bromphenylazo)-1,3-indandione and 2-methyl-2-(4-ethoxyphenylazo)-1,3-indandione

In the two title compounds, the 2-methyl-1,3-dioxoindan-2-yl and 4-(brom; ethoxy) phenyl groups aretrans with respect to one another. The phenyl ring and the azo group are not coplanar in the two molecules. The five-membered rings of the two compounds adopt an envelope conformation. The crystallographic parameters are as follows: 2-Methyl-2-(4-bromphenylazo)-1,3-indandione (I): monoclinic, P2₁/a witha=8.098(2),b=14.442(2),c=12.554(1)Å, =100.55(2)^o, andD _calc=1.58 g cm^–3 forZ=4; 2-methyl-2-(4-ethoxyphenylazo)-1, 3-indandione (II): monoclinic, P2₁/a witha=8.258(2),b=14.449(1),c=13.559(2)Å, =101.19(1)^o, andD _calc=1.29 g cm^–3 forZ=4.     

Crystal and molecular structures of tri(o-tolyl)phosphinegold(I) purine-6-thiolate ethanol solvate (1/1) and tri(c-hexyl)phosphinegold(I) 6-methyl-2-thiouracilate

The crystal and molecular structures of the title compounds, [(o-tol)₃PAu(6-MP)]·EtOH and [(c-hexyl)₃PAu(6-Me-2-TU)], have been determined and each show the presence of a linear geometry about the Au atom; both of the thionucleobases function as thiolate ligands. Important interatomic parameters for [(o-tol)₃PAu(6-MP)] are Au–S 2.266(2), Au–P 2.239(2) and S–Au–P 177.03(8)° and for [(c-hexyl)₃PAu(6-Me-2-TU)]: Au–S 2.299(3), Au–P 2.244(3) and S–Au–P 176.1(1)°. Crystals of [(o-tol)₃PAu(6-MP)]·EtOH are monoclinic with space groupP2₁/n, and unit cell dimensionsa=10.067(2),b=10.518(2),c=25.416(4) , =98.42(2)°,Z=4. The structure was refined to finalR=0.040 for 4183 data withI3.0(I). Crystals of [(c-hexyl)₃PAu(6-Me-2-TU)] are monoclinic with space groupP2₁/c, and unit cell dimensionsa=9.692(4),b=15.822(4),c=15.775(3) , =94.00(2)°,Z=4,R=0.033 for 2666 data.     

Crystal and molecular structures of several tetrakis (nitrile)copper(I) complexes

The crystal structures of several [Cu(RCN)₄]X salts (R = Me, X = SO₃CF₃ ^–; R = Ph, X = BF₄ ^–, ClO₄ ^–, and PF₆ ^–) were determined using single crystal X-ray diffraction. All of the compounds contain distorted tetrahedral Cu(I) centers and noncoordinating anions, with the acetonitrile and benzonitrile structures containing three and one unique CuL₄ ⁺ complex in their respective asymmetric units. One important distortion is observed in the benzonitrile-Cu bonds, which are bent up to 23° away from linearity. The result is a flattened complex that maximizes the – tacking of the aromatic rings and is the dominant packing interactions between the complexes.     

Crystal structures of 3-methyl-1,2,4-benzotriazine 1-oxide and 2-oxide

The compound 3-methyl 1,2,4-benzotriazine 1,4-dioxide (1) belongs to a new class of clinically promising, bioreductively-activated antitumor drugs. Reductive metabolism of these triazine di-N-oxides typically produces mixtures of mono-N-oxide analogues. As part of our efforts toward characterization of the in vitro metabolism of 1, we synthesized the 1-oxide (2) and 2-oxide (3) analogues and characterized these compounds using X-ray crystallography. Compounds 2 and 3 (C₈H₇N₃O) crystallized in the monoclinic space group P2₁/c. Unit cell parameters for 2: a = 9.0466(7), b = 10.5959(8), c = 7.8981(6) ?, β = 98.4940(10), and z = 4. Unit cell parameters for 3: a = 5.7193(4), b = 9.3774(7), c = 13.8427(11) ?, β = 101.6370(10), and z = 4.Supplementary material X-ray crystallographic data reported in this paper is deposited with the Cambridge Crystallographic Data Center as supplementary publication numbers CCDC 294738 (compound 2) and CCDC 294739 (compound 3). Copies of available material can be obtained, free of charge, on application to the Director, CCDC, 12 Union Road, Cambridge CB21EZ, UK.     

Crystal and molecular structure of 3-mesityl-4-methyl-5-(3′-mesityl-5′-methyl-Δ2′-isoxazolin-4′-yl)-Δ2-isoxazoline,C26H32N2O2

The crystal structure of the title compound, C₂₆H₃₂N₂O₂, has been determined by three-dimensional X-ray diffraction methods. The crystals are monoclinic:P2₁/c,a=13.338(9),b=17.364(12),c=10.320(8) Å,=99.84(6)°,Z=4. The structure was solved by direct methods, and refined to anR value of 0.069 for 2258 observed reflections. Bond lengths and angles have normal values. The isoxazoline rings are in an envelope conformation and their best planes are twisted by 77.8°; the mesityl groups are inclined to the heterocyclic rings (63.3 and 69.0°). No significant conjugation is evident within the molecule.     

Crystal and molecular structure of bis(8-phenylmenthyl) 2-(2-methyl-5-oxo-3-cyclohexen-1-yl)propandioate, C42H54O5· CH3CN

The X-ray crystal structure of the title compound, as crystallized from acetonitrile-water was determined. The relative stereochemistry of the cyclohexenone ring with respect to the 8-phenylmenthyl esters was determined. The title compound crystallizes in the noncentrosymmetric space group P2₁, with a=8.9850(10) ?, b=15.575(3) ?, c=14.478(2) ?, β=94.61(2)°, and D _calc=1.118 g cm⁻³ for Z=2.     

Crystal structures of 2-formyl-6-methyl- and 6-bromo-2-formylpyridine 4-phenylthiosemicarbazones

New thiosemicarbazones—2-formyl-6-methylpyridine 4-phenylthiosemicarbazone (I) and 6-bromo-2-formylpyridine 4-phenylthiosemicarbazone hydrate (II)—were synthesized and their structures were determined. Molecules I and II are nonplanar, the phenyl moiety at the terminal nitrogen atom being rotated by 19.9° and 39.5°, respectively. The water molecule is the main factor determining the crystal packing of molecules II.     

Crystal and molecular structure of 2-isopropylidene-5-methyl-1,3-dithiolane-1-oxide,C7H12OS2

The acid catalyzed cyclization of 2-propyl(allylthio)sulfine to methyl substituted 2-isopropylidene-1,3-dithiolane-1-oxide occursvia enethiolization of the sulfine followed by an intramolecular addition of thus formed sulfenic acid to the olefinic bond. Crystal data: C₇H₁₂OS₂,M _r=176.3, orthorhombic, space group Pbca,a=9.5551(13),b=17.3407(18),c=10.6417(9)Å,V=1763.2(3)ų,Z=8. The structure was solved by a combination of Patterson and direct methodswR ₂=0.115 for 1554 observations and 106 parameters. The stereochemical relationship between the methyl and sulfoxide oxygen iscis.     

Crystal and molecular structure of: 5-(1-oxoethyl)-1-methyl-2-(5-bromo-6-methoxy-2-naphthyl)-6-oxabicyclo[3.2.1]octan-7-one and 5-(1-oxoethyl)-1-methyl-2-(5-bromo-6-methoxy-2-naphthyl)-6-oxabicyclo[3.2.1]octane

X-ray crystallographic studies of the two title compounds have shown that the molecules crystallize in the same triclinic space group, , with very similar cell dimensions. For C₂₁H₂₁BrO₄,a=12.056(5),b=13.206(5),c=7.595(3)Å, =90.38(3), =106.07(3) and =124.42(3)° and for C₂₁H₂₃BrO₃,a=12.076(6),b=13.090(5),c=7.490(3)Å, =92.65(5), =104.90(5) and =124.55(5)°. Both compounds possess the oxabicyclo[3.2.1]octane bridged ring system and differ only at the carbon to the ring oxygen where the Csp³ in the ether is replaced by Csp²=O in the lactone. Both cyclohexane rings adopt distorted chair conformations and the lactone and ether rings approximate closely to the envelope conformation. The bromine substituent at C(4) results in distortion of the naphthalene ring. Both molecules pack with the naphthalene rings parallel to each other with interplanar spacings of 3.71 Å in the ether and 3.66Å in the lactone.     

Crystal structures of two modifications of sodium pentahydrogendiphosphate NaH5(PO4)2

Two crystalline modifications of NaH₅(PO₄)₂ are obtained by the reaction of Na₂CO₃ with an excess of orthophosphoric acid. The crystal structures of α-and β-NaH₅(PO₄)₂ are determined by X-ray diffraction analysis. The crystal data are a = 8.484(4) Å, b = 7.842(3) Å, c = 10.353(4) Å, β = 90.50(3)°, V = 689.3(3) ų, space group P2₁/c, Z = 4, and R ₁ = 0.0250 for the α modification and a = 7.127(2) Å, b = 13.346(4) Å, c = 7.177(2) Å, β = 95.5(2)°, V = 679.5(3) ų, space group P2₁/c, Z = 4, and R ₁ = 0.0232 for the β modification. Based of the hydrogen-bond system, the formulas of the α and β modifications can be represented as Na(H₂PO₄)(H₃PO₄) and Na[H(H₂PO₄)₂], respectively. They correspond to the stable and metastable forms of the compound.     

Crystal structure of racemic 5-(p-nitrobenzoylamino)-5-methyl-4-oxo-1,3-dioxane

C₁₂H₁₂N₂O₆ crystallized from methanol in the monoclinic space group P2₁/c (Z=4) witha=13.333(4),b=10.154(3),c=9.597(2) Å and=102.37(2)°.M _r=280.24,V=1269.1(6) ų,D _x=1.466 g cm^–3,(Mo K)=0.71069 Å,=1.29 cm^–1,T=295 K. The structure was solved by direct methods and refined by full-matrix least-squares to a finalR (R _w)=0.049 (0.057) for 916 observed reflections. The molecules are linked by strong N-HO(4) hydrogen bonds with NO distance of 2.995(4) Å. The infinite racemic chains run in [001] direction.