共查询到20条相似文献,搜索用时 31 毫秒
1.
Anne Irving 《Journal of chemical crystallography》1992,22(5):533-540
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 (CAr-N) bond such that the angles NHO=C, CArHArO=C, NHOHArCAr, 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. 相似文献
2.
Steven J. Archer Klaus R. Koch Luigi R. Nassimbeni 《Journal of chemical crystallography》1986,16(4):449-458
The crystal structure of a well-defined 5-coordinate complex, dichloro-(2,26, 2-terpyridyl)-tin(II), is described. The stereochemistry of this complex is strongly influenced by the stereochemically active pair of electrons, illustrating clearly the potential donor capabilities of this molecule. The complex (C15H11Cl2N3Sn) crystallizes in the monoclinic space groupC2/c (No. 15) witha=15.770(5),b=9.450(2),c=10.482(2) Å,=97.53(2)°,Z=4. The finalR value is 0.029 for 1085 observed reflections. 相似文献
3.
Gösta Brunow Pirkko Karhunen Knut Lundquist Solveig Olson Rolf Stomberg 《Journal of chemical crystallography》1995,25(1):1-10
Lignin models of the biphenyl type have been synthesized and crystal structures of two of them have been determined. The tetraacetate of 5,5-bis(hydroxymethyl)-3,3-dimethoxy-2,2-biphenyldiol crystallizes in space group
witha=11.319(2),b=12.232(6),c=9.242(3) Å, =101.66(3)°, =108.14(2)°, =79.08(2)° andZ=2.R=0.036 (2720 observed [I>3(I)] reflections). The acetate of 5,5-di-tert-butyl-2,3,3-trimethoxy-2-biphenylol crystallizes in space group
witha=11.972(2),b=21.621(3),c=9.834(1) Å, =91.18(1)°, =113.13(1)°. =98.42(1)°, andZ=4.R=0.050 (8129 observed [I>3(I)] reflections).1H NMR and13C NMR data for the above-mentioned compounds and a third model, the diacetate of 5,5-bis(1-hydroxyethyl)-2,2,3,3-tetramethoxybiphenyl, are reported. Observed signal positions are compared with those calculated on the basis of crystal structure data. The possibilities to obtain structural information about biphenyl structures in lignins from NMR spectra are discussed. 相似文献
4.
Crystals of 5-ethyl,5-(1,3-dimethylbut-2-enyl) barbituric acid (13M2B), mp 139°C, are triclinic, space groupP¯1,Z=2, witha=8.134(2),b=9.210(2),c=9.265(2),=91.91(1),=105.66(2), and =96.83(2)°. The structure was solved by direct methods, and refined by least-squares procedures to giveR=0.065 for 2056 observed diffraction data. The 5-ethyl and the 1,3-dimethylbut-2-enyl groups are both directed over the plane of the barbiturate ring. It is suggested that the conformation of the latter is stabilized by interactions between the isobutenyl group and the delocalized system of the ring. 相似文献
5.
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. 相似文献
6.
Wayland E. Noland Michael J. Konkel Susan J. Fanburg Shankar Venkatraman Doyle Britton 《Journal of chemical crystallography》1999,29(1):9-14
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. 相似文献
7.
Theophilus C. A. Afonya Faithwin B. M. Epelle W. Basil Whalley George Ferguson Masood Parvez 《Journal of chemical crystallography》1985,15(3):289-299
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. 相似文献
8.
L. P. Battaglia A. Bonamartini Corradi A. Marzotto L. Menabue G. C. Pellacani 《Journal of chemical crystallography》1988,18(1):101-112
The spectra (IR and NMR) of the nickel(II) and palladium(II) complexes of dithiomalonamide (Hdtma) andN,N-diphenyldithiomalonamide (Hdpdtma) are discussed in the light of the structure of the bis(N,N-diphenyldithiomalonamidato) nickel(II) di(N,N-dimethylformamide)solvate. The compound crystallizes in the triclinic space groupP¯1 (No. 2) witha=11.113(2),b=10.173(2),c=9.912(1) Å,a=74.47(6),=108.83(7),=114.10(7)°,Z=1 (R=0.0495 andR
w
=0.052). The crystals consist of discrete [Ni(dpdtma)2] andN,N-dimethylformamide (DMF) molecules. The nickel atom is chelated by two centrosymmetrically related ligands via sulfur atoms in an approximately squareplanar arrangement. The ligand moiety in the nickel coordination forms a-conjugation system. The DMF solvate molecules are involved in hydrogen bonding with the NH groups of the ligand. The best fit of the IR band assignments was obtained by comparing the spectra of the complexes with those of 相似文献
9.
Lingqin Han Wen-Hua Sun Leyong Wang Honggen Wang Yong Cui 《Journal of chemical crystallography》2003,33(3):159-163
Bis(2,6-(2,6-diisoproylanil)diformyl-4-chloro-phenolate) nickel(II) was prepared by the reaction of 2,6-(2,6-diisoproylanil)diformyl-4-chloro-phenol with nickel chloride. The title complex crystallized in P21/c, with cell dimensions a = 9.962(2) Å, b = 12.087(3) Å, c = 24.445(6) Å, and = 97.032(5), giving a volume of 2921.4(13) Å3. The bis(2,6-(2,6-diisoproylanil)diformyl-4-chloro-phenolate) nickel(II) adapts an ideal parallelogram, in which the Ni atom is coordinated with two phenolic oxygen atoms [O(1), O(1A)] and two imino nitrogen atoms [N(1), N(1A)]. 相似文献
10.
Crystals oftrans-5-ethyl-5-(1,3-dimethylbut-1-enyl) barbituric acid (13M1TB), mp 183° C, are triclinic witha = 7.677(2),b = 10.393(3),c = 9.176(3) Å, = 104.331(1), = 106.919(1), = 96.494(1)°, space group P, with two molecules in the unit cell. The structure was solved by direct methods and refined by least-squares procedures toR = 0.050 for 2809 observed diffraction maxima. The 5-ethyl group is oriented under the barbiturate ring with the orientation of the but-1-enyl group directed away from the ring. This orientation is determined by the 1-methyl substituent. The molecules are linked together by N-H ... O=C hydrogen bonds across inversion centers, thus forming single ribbons alongb. Adjacent ribbons are held together in theac plane by van der Waals interactions between alternating ethyl and l,3-dimethylbut-l-enyl groups. 相似文献
11.
Franz Pertlik Werner Mikenda Erich Steinwender 《Journal of chemical crystallography》1993,23(5):389-395
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. 相似文献
12.
Rabih O. Al-Kaysi David Creed Edward J. Valente 《Journal of chemical crystallography》2004,34(10):685-692
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) Å3 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) Å3 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. 相似文献
13.
Anne Irving Harry M. N. H. Irving Klaus R. Koch 《Journal of chemical crystallography》1987,17(2):167-175
The structure of Wallach's compound, C7H4O3NCl9, prepared in 1874 from concentrated aqueous solutions of potassium cyanide and chloral hydrate, has long been undecided. By single crystal X-ray crystallography it has now been established astrans-2,5-bis(trichloromethyl)-N-(1-hydroxy-2,2,2-trichloroethyl)-4-imino-1,3-dioxolane, confirming the tentative assignment by1H and13C NMR spectrography. The title compound is monoclinic,P21/c;a=8.445 (1),b=10.948(1),c=17.923(4) Å;=94.36(1)°;Z=4. The structure was solved by direct methods, from data collected at room temperature on an Enraf-Nonius CAD4 diffractometer, and refined by least squares to a finalR value of 0.041 using 2101 reflections. 相似文献
14.
J. Llorca E. Molins C. Miravitlles V. Cody J. C. Wallet E. M. Gaydou 《Journal of chemical crystallography》1993,23(6):481-484
7-Hydroxy-2,3,4-trimethoxyflavone, (C18H16O6),M
r
=328.32 crystallizes in the orthorhombic system, space groupPbna, with the following crystal data:a=8.853(2),b=12.870(2),c=26.293(3)Å,V=2996(1)Å3,Z=8, MoK, =0.67 cm–1,D
c
=1.454 g·cm–3,F(000)=1376,T=294K. The structure was solved by direct-methods and has been refined by full-matrix least-squares methods to a finalR value (F>(F)) of 0.0496. The molecule is not planar, the dihedral angle between the phenyl ring and the fused ring system is 27.3°. There are no intramolecular hydrogen bonds, but intermolecular short hydrogen contacts exist between hydroxyl hydrogen and carbonyl oxygen atoms. 相似文献
15.
Donald F. Mullica Kevin G. Pinney Koren M. Dingeman Ashley D. Bounds Eric L. Sappenfield 《Journal of chemical crystallography》1996,26(12):801-806
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. 相似文献
16.
Jacqueline Vitali 《Journal of chemical crystallography》1990,20(3):251-259
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). 相似文献
17.
A. Guiotto G. Bandoli P. Manzini P. Rodighiero 《Journal of chemical crystallography》1987,17(3):349-364
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. 相似文献
18.
John R. Peterson Shahla Peterson John K. Baker Robin D. Rogers 《Journal of chemical crystallography》1990,20(4):327-333
The title compound, C20H14O8, Mr=382.3, crystallized from chloroform in the centric space group P¯1 witha=6.516(4),b=6.798(3),c=9.545(7) Å,=85.31(5),=73.87(5), =79.59(4)°,V=399.2 Å3, and Dcalc=1.59 g cm–3 forZ=1. Least-squares refinement of 1035 observed [Fo5(Fo)] reflections led to the final agreement index ofR=0.074. The molecule resides on a crystallographic center of inversion and is disordered into two different conformations. This manifests itself as a 50/50 disorder at O(4), C(2), and C(3). The observed structure reveals acis relationship between the bridgehead hydrogen atoms and the aryl rings. The 90 MHz1H nmr spectrum of the title compound exhibits an AAXX spin system with a H(1)C(2) to H(1)C(3) and H(1)C(2) to H(1)C(3) coupling constant of 2.8 Hz. Computer spectral simulation and Karplus equation analysis are utilized to illustrate a relaxation of the torsion angles between H(1)C(2) and H(1)C(3), and H(1)C(2) and H(1)C(3) is solution. 相似文献
19.
Christopher W. Miller Charles E. Hoyle Edward J. Valente Jeffrey D. Zubkowski E. Sonny Jönsson 《Journal of chemical crystallography》2000,30(9):563-571
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. 相似文献
20.
Fulvia Orsini Gabriella Bombieri Franco Benetollo M. Gabriella Vigorita Tindara Previtera 《Journal of chemical crystallography》1995,25(9):589-595
3,3(1,2-Ethanediyl)bis(2-halophenyl-thiazolidin-4-one) derivatives display different pharmacological activities depending on the configuration of the 2,2 centers and on the oxidation state of the sulfur atoms. Quantum-chemical calculations on the 3-fluorophenyl-substituted configurational isomers are reported here, together with the X-ray structure of the 11 dioxide derivative. This crystallizes in the monoclinic space group P21/c, with four molecules per unit cell and cell dimensions:a=18.917(3),b=9.003(2),c=12.062(2)Å, =96.20(3)°. The compound, which has an approximate center of symmetry in the middle of the ethylene chain and two asymmetric carbon atoms of opposite chiralities, is the (2R,2S-meso) (or 2S,2R-meso) stereoisomer. 相似文献