Crystal structures of 3,5,5′-trichloro-2,2′-bithiophene and 3,3′,5,5′-tetrachloro-2,2′-bithiophene

The crystal structures of 3,5,5-trichloro-2,2-bithiophene (I) and 3,3,5,5-tetrachloro-2,2-bithiophene (II) have been determined by single crystal X-ray diffraction techniques. BothI andII crystallize in the monoclinic crystal system. ForI,a=3.895(2),b=11.928(2),c=10.701(2)Å,=97.70(1)°, space groupP2₁,Z=2 and forII,a=8.942(2),b=3.900(2),c=15.180(2)Å,=92.30(1)°, space groupP2₁/n,Z=2. The structures have been solved by direct methods and all nonhydrogen atoms refined with anisotropic thermal parameters. ForI the final residual is 0.035 (all 1185 independent reflections, MoK radiation) and forII, 0.034 (all 1209 independent reflections, MoK radiation). BothI andII have theanti conformation butI has a torsion angle of 3.4(5)° between the two thiophene rings whileII is completely planar.     

N-Arylmaleimide derivatives

Nine phenyl substituted N-phenylmaleimide monomers for photopolymerization studies have been characterized by x-ray crystallography. Structures for N-(2-t-butylphenyl)maleimide (1), P2₁/n, a = 10.197(3) Å, b = 11.904(4) Å, c = 10.496(5) Å, = 100.61(3)° N-(2-trifluoromethylphenyl)maleimide (2), P2₁/c, a = 11.763(8) Å, b = 10.699(9) Å, c = 8.284(5) Å, = 90.02(5)° N-(2,6-diisopropylphenyl)maleimide hemibenzene solvate (3), Pc, a = 16.747(6) Å, b = 8.552(3) Å, c = 12.899(4) Å, = 105.08(3)° N-(2,6-diisopropylphenyl) maleimide (unsolvated) (4), C2/c, a = 28.146(10) Å, b = 8.434(4) Å, c = 12.881(4) Å, = 92.20(4)° N-(2-bromo-3,5-bis(trifluoromethyl)phenyl) maleimide (5), P2₁/n, a = 8.7115(16) Å, b = 16.125(3) Å, c = 9.6707(19) Å, = 99.757(15)° N-(2-phenylphenyl)maleimide (6), P2₁/n, a = 8.519(4) Å, b = 13.742(5) Å, c = 11.147(4) Å, = 92.25(3)° N-(4-methoxyphenyl)maleimide (7), P2₁/n, a = 9.320(3) Å, b = 6.621(2) Å, c = 16.059(6) Å, = 99.58(3)° N-(2-trifluoromethylphenyl)-2-methylmaleimide (8), Fdd2, a = 43.362(12) Å, b = 8.202(2) Å, c = 12.720(4) Å and N-(2-trifluoromethylphenyl)-2-methanosuccinimide (9), Cc, a = 7.708(2) Å, b = 22.191(9) Å, c = 7.137(2) Å, = 115.76(2)° are described. Molecules with bulky 2-substituents show larger rotations between the mean phenyl and maleimide ring planes, and varying degrees of distortion to the imide group.     

Crystal structure of syn-1-acetyl-9′aH-8′- methoxyspiro[indole-3,2′-oxeto[3′,2′:4,5]furo[3,2-g][1] benzopyran]2,6′-dione

The crystal structure of syn-1-acetyl-9a-hydro-8-methoxyspiro[3H-indole-3,2(2aH) oxeto[3,2-g]furo[3,2-g]benzo[ b]pyran-2,6-dione 1 was determined by X-ray diffraction analysis. It possesses P2(1)/c space group symmetry, with a = 12.391(3), b = 15.035(3), c = 9.5435(19) Å, = 93.66(3), and D _calc. = 1.517 Mg/m³ for Z = 4.     

Synthesis and crystal structures of 4,4′-bipyridinium and 2,2′-bipyridinium pentachloro complexes containing the polynuclear anions [Bi2Cl10]4− and [Bi4Cl20]8−

The compounds 4,4-bipyridinium(2+) pentachloro-bismuthate(III) (1), [4,4-(C₁₀H₈N₂)BiCl₅] and 2,2-bipyridinium(2+) pentachloro-bismuthate(III) (2), [2,2-(C₁₀H₈N₂)Bi₂Cl₁₀] have been obtained by reacting bismuthate oxide and 4,4-bipyridine or 2,2-bipyridine in HCl acid medium. They have been characterized by single crystal X-ray analysis. (1) crystallizes in the triclinic space group with a = 9.776(2), b = 11.009(3),c = 8.346(1) Å, = 101.58(2), = 98.63(2), and = 112.86(2)°. (2) crystallizes in the monoclinic space group P2₁/c with a = 14.239(2), b = 14.226(2), c = 16.275(3) Å, and = 110.15(2)°. The crystal structure of (1) consists of 4,4-bipyridinium(2+) cations interacting through hydrogen bonding with [Bi₂Cl₁₀]^2– dimers giving rise to endless double chains, while that of (2) is formed by 2,2-bipyridinium(2+) cations and [Bi₄Cl₂₀]^8– tetramers extensively interacting through hydrogen bonding. The different polynuclearity of the anions seems related to the different directions along which each cation can form hydrogen bond interactions.     

X-ray structures of two methoxybenzo[b]thiophenes

The crystal and molecular structures of two methoxybenzo[b]thiophenes have been determined by three-dimensional, single-crystal X-ray diffractometry. Both 3-(4-hydroxy-3, 5-dimethoxybenzoyl)-2-(4-methoxyphenyl)-6-methoxybenzo[b]thiophene and 3-(2,6-dimethoxybenzoyl)-2-(4-methoxyphenyl)-6-methoxybenzo[b]thiophene (hereafter referred to asI andII, respectively) crystallize in the monoclinic centrosymmetric space groupP2₁/n (No. 14, C _2h ⁵ ) with four formula units-per cell witha=6.866(1),b=28.638(2),c=11.830(2) Å, and =105.52(1)° anda=9.328(1),b=7.977(1),c=29.650(4) Å, and =97.87(1)°, respectively. The phase problems were solved by direct methods and the respective final full-matrix least-squares refinements converged toR=0.046 and 0.031. The structures differ in the positioning of the dimethoxy groups of the benzoyl ligands and the addition of a hydroxyl group inI. The molecules in the crystal lattice are held together by van der Waals forces plus the addition of hydrogen bonding in compoundI. Selected bond distances and angles and torsion angles are tabularized.     

Crystal structures of two substituted biphenyl derivatives: 5,5′-di t-butyl-2-2′-biphenyldiol and 5,5′-dimethyl-2,2′-biphenyldiol

5,5-Di t-butyl-2,2-biphenyldiol (I), C₂₀H₂₆O₂, crystallizes in the orthorhombic space group P2₁2₁2₁ with a = 18.243(2), b = 9.947(2), c = 9.685(3) Å, and Z = 4; 5,5-dimethyl-2,2-biphenyldiol (II), C₁₄H₁₄O₂, crystallizes in the monoclinic space group P2₁/c with a = 9.959(2), b = 7.932(3), c = 15.392(2) Å, = 105.43(2)°, and Z = 4. The aromatic rings are tilted by 52.7(1) and 43.8(1)° to each other in compounds (I) and (II), respectively. Strong intra- and inter-molecular H-bonds connect the molecules in the crystals.     

The chemistry of the “insoluble red woods.” Part 15. The crystal structures of 7-benzyloxy-6,2′,3′,4′-tetramethoxy- and 2,6,7,2′,3′,4′-hexamethoxy-isoflav-3-ene

The reaction of 7-benzyloxy-6,2,3,4-tetramethoxyisoflavylium perchlorate with 1-(2,4-dimethoxyphenyl)-3-(3,4-dimethoxyphenyl)-prop-l-ene and of 6,7,2,3,4-pentamethoxyisoflavylium perchlorate with the same propene yielded respectively 7-benzyloxy-6,2,3,4-tetramethoxyisoflav-3-ene (5) and 2,6,7,2,3,4-hexamethoxyisoflav-3-ene (7) whose structures have been established by X-ray crystallography. Crystals of (5) are monoclinic, space groupP2₁/a (No. 14) with four molecules in a unit cell of dimensionsa=8.528(2),b=13.294(3),c=19.629(4) Å,=99.92(2)°. Crystals of (7) are also monoclinic, space groupC2/c (No. 15) with eight molecules in a unit cell of dimensionsa=28.088(3),b=10.662(3),c=12.869(1) Å,=97.32(1)°. Both structures were solved by direct methods and refined by full-matrix least-squares calculations to finalR values of 0.053 and 0.041 for 1673 and 1424 observed data for (5) and (7) respectively. The molecular dimensions are in accord with accepted values.For Part 14 see Whalley, W. B., Ferguson, G., and Khan, M. A., (1980)J. Chem. Res. (M), 2219.     

Two acetylamino derivatives of 2,4-bis(trichloromethyl)-1,3-benzdioxin showing different types of hydrogen bonding: (a) (C13C)CH⋯O=C and (b) N-H⋯O=C

8-Acetylamino-6-methyl-2,4-bis(trichloromethyl)-1,3-benzdioxin, (I), is monoclinic,P2₁/c,a=15.174(4),b=11.977(7),c=9.911(3)Å,=99.72(2)°. 6-Acetylamino-2,4-bis(trichloromethyl)-1,3-benzdioxin, (II), is monoclinic,P2₁/_n,a=5.927(4),b=40.623(1),c =7.120(3)Å,=91.39(4)°. In compound (I) the imino hydrogen atom is locked in an intramolecular hydrogen bond to the proximate oxygen atom of the heterocyclic ring and is not available for intermolecular hydrogen bonding. Instead the weakly acidic hydrogen atom [Cl₃C-C(2)]H takes part in a hydrogen bond to the carbonyl oxygen atom in another molecule. In compound (II) a normal intermolecular hydrogen bond of the type N-HO=C occurs. The 6-acetylam-ino group is twisted about the (C_Ar-N) bond such that the angles NHO=C, C_ArH_ArO=C, NHOH_ArC_Ar, at the carbonyl oxygen group total 360° (where NH is in the related molecule). The packing in both compounds takes the form of infinite chains and in compound (II) partial overlap of the aromatic ring and the acetylamino group, with very little offset, also occurs.     

Characterization and structural analyses of trimethoxy and triethoxybenzo[b]thiophene

The crystal and molecular structures of two methoxybenzo [b] thiophenes have been determined by three-dimensional, single-crystal X-ray diffractometry. Both 3-(3,4,5-trimethoxybenzoyl)-2-(4-methoxyphenyl)-6-methoxybenzo[b]thiophene and 3-(3,4,5-triethoxybenzoyl)-2-(4-methoxyphenyl)-6-methoxybenzo[b]thiophene (hereafter referred to as I and II, respectively) crystallize in the triclinic centrosymmetric space group (No. 2, C¹) with two formula units per cell with a = 6.842(1) Å, b = 12.602(2) Å, c = 13.815(2) Å, = 94.80(1)°, = 98.27(2)°, and = 100.59(2)° and a = 10.600(1), b = 11.415(2), c = 12.137(2) Å, = 94.57(1)°, = 101.18(1)°, and = 110.45(1)°, respectively. The phase problems were solved by direct methods and the respective final full-matrix least-squares refinements converged to R = 0.039 and 0.068. The structures differ in the orientation of the trimethoxy and triethoxy groups of the benzoyl ligands. The molecules in the crystal lattice are held together by van der Waals forces. Selected bond distances, angles, and torsion angles are tabularized as well as reference to the synthesis of the title compounds and peripheral studies.     

Crystal structure and charge distribution for 20 oximino-5α-pregn-16-eno[3, 4,-c]-1′2′5′-oxadiazole (HS998)

The crystal structure of the modified steroid, 20 oximino-5 pregn-eno [3, 4-c] 125 oxadiazole (HS998) using X-ray diffraction is reported. HS998 crystallizes in the orthorhombic space groupP2₁2₁2₁, having cell parametersa=13.465(3),b=18.792(4),c=7.598(2) Å;Z=4. The structure was solved by direct methods and refined by full matrix least squares toR=0.060 for 3478 reflections.     

Hydrogen-bonded networks formed by substituted 2,6-diarylpyrazines

The X-ray crystal structure of 2,6-bis(4-hydroxyphenyl)pyrazine and 2,6-bis(4carboxyphenyl)pyrazine are reported. The structure of the 2,6-bis(4-carboxyphenyl) pyrazine dimethylsulfoxide complex (C₁₈H₁₂N₂O₄)(C₂H₆OS) is triclinic, P-1, with a = 7.9933(8), b = 10.7165(10), c = 12.1337(12) Å, = 66.385(2), = 84.070(2), = 77.219(2). The structure comprises stacked two-dimensional sheets of the hydrogen bonded complex. The two-dimensional sheets comprise hydrogen-bonded ribbons of the (carboxyphenyl)pyrazine that are connected by bridging hydrogen bonds to the dimethylsulfoxide. The structure of 2,6-bis(4-hydroxyphenyl)pyrazine, C₁₆H₁₂N₂O₂, is monoclinic, P2₁/c, with a = 10.6107(13) Å, b = 14.6743(18) Å, c = 8.3772(10) Å and = 104.982(2). The structure reveals that two-dimensional hydrogen-bonded sheets are formed with pyrazine–phenol and phenol–phenol hydrogen bonds.     

The crystal structure of a novel product from the acid-catalyzed condensation of 1-benzylindole with acetone

The acid-catalyzed condensation of 1-benzylindole with acetone in the presence of N-phenylmaleimide gave a tetrahydrocarbazole, (4,5,10,10b-tetrahydro-5-methyl-2-phenyl-10-(phenylmethyl)pyrrolo[3,4-a]carbazole-1,3[2H, 3aH]-dione (1), as the major product and a novel spiro compound, 1,3,4,4-tetrahydro-1,1,3,3-tetramethyl-4,4-bis(phenylmethyl)-1,3(2H, 2H)-spiro[cyclopent[b]indole] (2), as the minor product. The structure of the spiro compound was determined by an X-ray crystallographic determination. The acid-catalyzed condensation of 1-benzylindole with acetone in the absence of N-phenylmaleimide gave a bisindole, (1,1-bis(phenylmethyl)-3,3-(1-methylethylidene)diindole (3), as the major product and the spiro-compound as the minor product.     

Synthesis and crystal and molecular structure of newN-substituted γ-hydroxybutyramides

TheN-(2-phenylethyl)amide of-(1, 1-ethylenedioxy)-ethyl--hydroxybutyric acid (II) and theN-(p-methoxybenzyl)amide of-(1, 1-ethylenedioxy)-ethyl--hydroxybutyric acid (III) have been synthesized and the crystal structure ofIII has been solved. CompoundIII, C₁₆H₂₃O₅N, crystallizes in the monoclinic space groupP2₁/c witha=12.572(2),b=11.149(2),c=12.317(2) Å and=106.53(1)°. The structure was solved by direct methods, and refined by full-matrix least squares to giveR=0.040 (R _w =0.047) for 2004 intensities. The dioxolane ring has a deformed half-chair conformation.     

Meisenheimer complex from picric acid and diisopropylcarbodiimide

Reaction of picric acid with diisopropylcarbodiimide produces a pale yellow 1:1 adduct N-(2,4,6-trinitrophenyl)-N,N-di(isopropyl)urea (5) and a 1:2 adduct fluorescent red zwitterionic Meisenheimer complex (6) as approximately N,N,N-tri(isopropyl)-4-oxo-6-(isopropyliminio)-2-s-(2H)triazinespiro-1-2,4,6-trinitro cyclohexadienylide. Crystals of (5) are triclinic, P-1 (#2), with a = 10.444(13) Å, b = 15.47(2) Å, c = 17.74(2) Å, = 110.43(9)°, = 99.85(10)°, = 92.78(10)°, V = 2629(6) ų for Z = 6 (three molecules per asymmetric unit). Crystals of (6) are orthorhombic, Pna2₁ (#33), with a = 24.12(4), b = 9.011(19) Å, c = 10.87(2) Å, V = 2362(8) ų for Z = 4. Nitro groups in the Meisenheimer complex are twisted 2–8° from the mean formerly aryl ring plane; in (5), nitro groups are twisted out of the aryl plane by 11–62°. In the Meisenheimer complex, cationic charge is distributed over an iminium/guanidinium group; anion charge is distributed over the cyclohexadienide ring and attached nitro groups.     

X-ray structure determination of cyclobutane photodimers from (Z)-α, β-diarylacrylonitriles

Irradiation of(Z)-, -diarylacrylonitriles (1) ArCH=C(CN)Ar (a: Ar=2-thienyl, Ar=Ph;b: Ar=p-MeC₆H₄, Ar=Ph) in the solid state gives cyclobutane dimers (2) in good yield. The mass spectra of the dimers, where no fragments derived from dimers with equal groups on adjacent carbons are present, suggest a truxillic structure (head to tail dimerization). X-Ray determinations confirm a centrosymmetric arrangement with a D_2d symmetry of the cyclobutane ring and a puckering constant=24.0° for (2a) significantly higher than that of (2b) (=19.2°).     

Hydrogen bonding in 2-hydroxy((di)thio)benzoates. I. X-ray structures of 2,6-dimethylpiperidinium salts

X-ray structural data are reported for 2,6-dimethyl-piperidinium-2-hydroxybenzoate (C₁₄H₂₁NO₃, orthorhombic,P2₁2₁,2₁, (19);a=7.983(1)Å,b=12.680(2)Å,c=13.838(2)Å;Z=4;R=0.042) and for two polymorphs of 2,6-dimethylpiperidinium-2-hydroxythiobenzoate (C₁₄H₂₁NO₂S), an-form (monoclinic,P2₁/n (14);a=8.005(4)Å,b=22.150(2)Å,c=8.672(4)Å,=101.91(6)°;Z=4;R=0.059) with an intramolecular O-HS hydrogen bond, and a-form (orthorhombic,P2₁2₁2₁ (19);a=8.188(1)Å,b=14.781(2)Å,c=24.163(4)Å;Z=8;R=0.15) with an intramolecular O-HO hydrogen bond. The intra-and intermolecular hydrogen bond patterns are discussed, including the literature data of 2,6-dimethylpiperidinium-2-hydroxydithiobenzoate.     

5-(thien-2-yl) uracil analogs: 5-(5-methylthien-2-yl)-2′-deoxyuridine, 5-(5-thien-2-yl)-2′-deoxyuridine,and 5-(5-bromothien-2-yl)-2′-deoxyuridine

Crystal structures of 5-(5-methylthien-2-yl)-2-deoxyuridine (I), 5-(5-thien-2-yl)-2-deoxyuridine (II) and 5-(5-bromothien-2-yl)-2-deoxyuridine (III) have been obtained from data collected on a four-circle Enraf-Nonius diffractometer (CAD-4 system). Space group, unit/cell parameters and finalR indices are:I, monoclinic,P2₁,a=9.105(2),b=20.819(2),c=7.932(2) Å, =98.79(2)°,R=5.7%;II, monoclinic,P2₁,a=8.720(4),b=20.793(4),c=7.884(4) Å, =95.06(2)°,R=5.8%;III, monoclinic,P2₁,a=9.260(2),b=41.655(7),c=7.926(2) Å, =97.996(13)°,R=9.4%. Structural properties of the title compounds are compared with those of 5-(5-chlorothien-2-yl)-2-deoxyuridine (IV) previously reported in order to explain their affinity for HSV-1 thymidine kinase and their eventual interaction with viral DNA polymerase. The main structural features observed are the coplanarity of the uracil and thienyl cycles stabilized by a S–O intramolecular interaction and the formation of dimeric intermolecular H bonds between two uracil moieties.     

Structure of 2,2′-anhydro-3′-O-acetyl-2′thio-1-β-D-arabinofuranosylcytosine hydrochloride1

2,2-Anhydro-3-O-acetyl-2-thio-1--D-arabinofuranosylcytosine hydrochloride crystallizes in space group P2₁2₁2₁ witha=10.373(1),b=14.517(2),c=9.496(1) Å. Reflections were measured on a diffractometer and the structure was solved by direct methods. Least-squares refinement converged atR=0.056 andR _w =0.063. The study of this crystal structure showed that the alterations in the geometry of 2,2-anhydro-1--D-arabinofuranosylcytosine when the bridge oxygen is replaced by sulfur are localized in the region of the fused ring. The angle at the bridge atom decreases to nearly 90°, with concomitant enlargements of about 5°–7° in the angles opposite to the bridge atom. Angle C(1)-N(1)-C(6) decreases by 4°. Also, the amount of double bond character in the bond formed by C(2) and the bridge atom decreases. A survey of the conformational features of S,2-cyclonucleosides and comparison with O,2-cyclonucleosidcs showed that their preferred conformations are the same. However, S,2-cyclonucleosides exhibit a wider range of P and values. This correlates with a greater ease of the sulfur containing five-membered ring to pucker as compared to the oxygen-cyclo ring.This paper is part of the authors' dissertation (Vitali, 1986).     

Structure of two 1,3-dioxane derivatives from 4′, 5′-dimethylfurocoumarins: 4a, 11a-dihydro-4a, 11a-dimethyl-8H-pyrano[3′,2′∶5,6]benzofuro[3,2-e]-1, 3-dioxan-8-one and 7a,11a-dihydro-7a,11a-dimethyl-2H-pyrano[2′, 3′∶4,5]benzofuro[3,2-d] (1,3) dioxan-2-one

Treatment of dimethylated psoralen and angelicin in the 4, 5-position leads to the formation of 1,3-dioxane derivatives, resulting from the condensation of an 1,3-dioxane ring to the 4, 5-positions of the dihydrofurocoumarin moiety. The structures of these new compounds, 4a, 1 1a-dihydro-4a, 11a-dimethyl-8H-pyrano [3, 25,6]benzofuro[3,2-e]-1, 3-dioxan-8-one (C₁₅H₁₄O₅) (1) and 7a, 11a-dihydro-7a, 11a-dimethyl-2H-pyrano[2, 34, 5]benzofuro[3, 2-d](1, 3)dioxan-2-one (C₁₅H₁₄O₅) (2) have been assigned by¹H and¹³C NMR measurements, mass spectrometry results, and X-ray analysis. Compound (1): triclinic,P¯1,a=9.847(2),b=8.927(2),c=8.334(2) Å,=95.98(2),=108.81(3), =106.73(3)°; compound (2): triclinic,P¯1,a=7.296(4),b=7.481(2),c=11.812(4) Å,=91.67(2),=95.97(4), =94.20(3)°. The structures were solved by direct methods and refined by full-matrix least squares toR=0.050 (1) and 0.056 (2). In both compounds the coumarin rings can be regarded as coplanar, while the five-membered ring adopts an envelope conformation and the 1,3-dioxane ring a chair conformation.     

Crystal and molecular structures of three 2,2′-thio- and 2,2′-sulfonyl-bis(1,3-diarylprop-2-en-1-ones)

The X-ray crystal structures of 2,2-thio- and 2,2-sulfonylbis(1,3-diarylprop-2-en-1-ones) are determined [1: 2,2-thiobis(3-(p-chlorophenyl)-1-phenylprop-2-en-1-one), C₃₀H₂₀Cl₂O₂S, space group C2/c, a = 14.275(3), b = 6.280(1), c = 26.533(5) Å, = 94.55(3)°, Z = 1/2; 2: 2,2-sulfonylbis(1,3-diphenylprop-2-en-1-one), C₃₀H₂₂O₄S, space group P , a = 9.652(1), b = 12.044(1), c = 12.182(1) Å, = 61.985(6), = 77.511(5), = 74.340(6)°, Z = 1; 3: 2,2-sulfonylbis(3-(p-chlorophenyl)-1-phenylprop-2-en-1-one), C₃₀H₂₀Cl₂O₄S, space group P , a = 8.294(1), b = 13.175(2), c = 13.470(1) Å, = 62.870(9), = 83.796(7), = 85.282(8)°, Z = 1]. The C=C double bonds are all clearly defined. The sulfide 1 crystallizes on a crystallographic twofold axis, leading to a symmetric molecular conformation. The sulfones 2 and 3 crystallize on general positions, with different and irregular conformations.