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1.
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.
The present compound crystallizes in the space groupP212121 withZ=4 and cell parametersa=21.687(2),b=8.155(3),c=5.883(2)Å. The structure was solved by direct methods and refined by full-matrix least-squares to a finalR value of 0.045 for 1153 observed reflections. The N-glycosidic torsion angle CN is in the anti-range and the pyranosyl ring adopts a distorted half-chair conformation with 2=142.7(4)°, 2=124.4(3)° andQ=0.456(2)Å. In the crystal packing the molecules are linked together by N-HO hydrogen bonds and C-HO contacts.  相似文献   

3.
The title compound, C8H4N8O4·3H2O, crystallizes in space groupP¯1 with cell constantsa=7.022(1),b=9.507(2),c=10.906(2) Å,=84.99(1),=71.89(1),=72.56(1)°,Z=2, andV c =660.2 Å3. The structure was solved by direct methods using diffractometer data and was refined by full-matrix least-squares methods to anR value of 0.060 for 2112 observed reflections. The molecule, consisting of a phenyl ring fused to a pyrazole ring with a tetrazole ring connected to it equatorially, is planar except for the N(7) nitro-group oxygen atoms. The structure is stabilized by a three-dimensional network of O-HO, O-HN, and N-HO hydrogen bonds through the water molecules.  相似文献   

4.
The title compound is C19H18O4·1/2 CH3OH, triclinic,P¯1,a=9.891(2),b=13.273(4),c=13.860(4) Å,a=66.47(2),=86.91(2), and =85.59(2)°. The structure was solved by direct methods and refined by least-squares techniques to anR factor of 0.082 for 2282 observed reflections. The X-ray structure uniquely resolves the one remaining ambiguity, namely the assignment of the correct structure4. There are two crystallographically independent molecules (A and B) and one disordered methanol molecule. Both molecular skeletons show small distortions from planarity with inclinations of 1.7 and 4.0° between the outermost rings A/C in molecules A and B, respectively. Intramolecular hydrogen bonds of the form O(3A)-HO(2A) and O(3B)-HO(2B) are observed in molecules A and B, respectively. The molecules are linked by pairs of O(3A)-HO(2B) and O(3B)-HO(2A) hydrogen bonds. The dimerlike structures are stabilized by intermolecular C-HO interactions and van der Waals forces.  相似文献   

5.
The title complex has been prepared, and characterized by X-ray crystallography. The crystals are rhombohedral, space groupR32, witha=20.954(5),c=9.753(1) Å,Z=3, andR F =0.070 for 680 observed MoK reflections. The structure consists of a packing of hexa(3,5-dicarboxypyridine) potassium cations and tetrabromoaurate(III) anions. The potassium atom is surrounded by equivalent oxygen atoms to form a KO6 octahedron with a very short K-O distance of 2.56(1) Å. The AuBr 4 group exhibits orientational disorder with a mean bond length of 2.38(1) Å. Two symmetric strong hydrogen bonds (linear OHO and bent NHN) are found in the crystal structure. The nearly planar organic ligands are interlinked by hydrogen bonds to form parallel sheets which approximately correspond to the (003) family of planes. The potassium atoms lying in between these sheets connect them into a three-dimensional network.On leave from Central Laboratory, Nankai University, Tianjin, China.  相似文献   

6.
The title compound is monoclinic,P21/n,Z=4,a=9.934(1),b=18.399(2),c=11.098(2)Å, =111.08(1)°. The molecule can conveniently be visualized as a benzophenone molecule with one of the aromatic rings fused to a 1,3-dioxin ring which adopts a distorted envelope conformation withcis-trichloromethyl groups substituted at positions 2 and 4. An interaction, observed for the first time, involves a hydrogen atom and a chlorine atom from opposite sides of the same aromatic ring to give C-H-(Ar)Cl-C. The parameters are Hring-centroid 2.63 A, Clring centroid 3.41 Å, Hring-centroidCl 167°, C-Hring centroid 159°, C-Clring centroid 150.2°. The (Ar) system is that of the unfused aromatic ring. A second (Ar) Cl-C interaction occurs but this time with the (Ar) system of the fused aromatic ring. The ClCl and ClO(=C) interactions form the familiar zig-zag pattern which has been noted for many chloroaromatic compounds.  相似文献   

7.
Crystals of the title compound are monoclinic,P21,a=9.791(4),b=7.129(3),c=10.428(3)Å,=91.84(3)°,V=727.50Å3,Z=2. The structure was solved by direct methods, from data collected at room temperature on an Enraf-Nonius CAD4 diffractometer, and refined by full matrix least squares to a finalR value of 0.045 using 2466 reflections. The molecules form stacks along theb axis of the formA, B, A, B(A=dichloromethylene group; B=aromatic ring in the molecule at –x, 1/2+y, –z to the molecule atx, y, z containing A). Cl(Ar),, ClCl, ClO(N), (Cl3C)HO intermolecular interactions are also present. An inverse correlation between the (C)ClCl(C) distance and the difference in the corresponding pairs of C-ClCl angles is observed and is interpreted in terms of incipient nucleophile: electrophile attack.  相似文献   

8.
The title compound, 1-(2,3-dideoxy-3-fluoro--d-erythro pentofuranos-1-yl)-5-chlorocytosine, crystallises in the orthorhombic space groupP212121 witha=5.142(1),b=14.177(2),c=15.721(2) Å,Z=4. The crystal structure was solved by the heavy atom method and refined by full-matrix least-squares method to a finalR value of 0.031 for 1629 unique observed reflections. The N-glycosidic torsion angle is –156.1(2)° and the sugar moiety is anti to the cytosine base. The sugar pucker is 2 3 T withP=178.2(1)° and=31(1)°. The atom 05 is in a +sc conformation with respect to the furanose ring. The molecular packing in the crystal is stabilized by N-HN, N-HO, O-HO hydrogen bonds and C-HO close contacts.  相似文献   

9.
The title compound crystallizes in the orthorhombic space groupP212121 witha=5.084(1),b=14.322(3),c=16.065(2)Å,Z=4. The structure was solved by the heavy atom method and refined by full-matrix least-squares calculations to a finalR value of 0.033 for 1106 unique observed reflections. The N-glycosidic torsion anglex has a value of –153.7(4)°, in the anti-range. The sugar pucker is2T3 withP=175(1)° and=30(1)°. The C4-C5 conformation is + sc with =46.7(7)°. The structure is stabilized by N-HN, N-HO and O-HO hydrogen bonds and C-HO close contacts.  相似文献   

10.
C22N2O5H32,M r =404.5, monoclinic,C2,a=21.781(5),b=5.065(1),c=22.333(4)Å,=112.81(2)°,V=2271.1(9)Å3,D calc=1.148 g cm3, (CuK )=1.5418 Å,=5.89 cm–1,F(000)=848, room temperature,R=0.058 for 2178 unique reflections [I2.5(I)]. The peptide linkage is in thetrans conformation. The molecule adopts the-sheet structure. The crystal structure is stabilized by a three-dimensional network of N-HO and C-HO hydrogen bonds.DCB Contribution No. 813.  相似文献   

11.
The title compound1 crystallizes as colorless polyhedra in the monoclinic polar space groupCc, witha=8.107(2),b=21.577(3),c=9.542(2)Å,=103.58(2)°, by contrast with its thioether precursor3, crystals of which have the trigonal space groupR¯3. The structure comprises infinite chains of molecules linked head-to-tail by S=OHO hydrogen bonds of length 2.723(2)Å, with HO contact 1.97(4)Å and O-HO 177(3)°; HÔ=S 146(1)°.  相似文献   

12.
The crystal and molecular structure ofp-aminobenzene sulfonacetamide sodium, C8H9N2NaO3S·H2O, an important substituted sulfa drug, has been determined from diffractometric data using MoK radiation. The crystals are monoclinic, witha=6.614(2),b=23.788(6),c=7.012(2) Å,=103.13(2)°, and space groupP21/c. The structure was solved by the heavyatom method, and refined by full-matrix least squares to a finalR value of 0.040 with 1435 unique reflections. In packing, the molecules form dimers through pairs of N-HN and N-HO hydrogen bonds. The molecules are further stabilized by O-HO and O-HN hydrogen bonds.  相似文献   

13.
The crystal structure of the title compound has been determined from three-dimensional X-ray diffraction data, and refined by full-matrix least-squares techniques. The crystals belong to the monoclinic space groupP21/c, witha = 8.849(4),b = 13.798(5),c = 7.943(4) Å, = 102.98(3) °, andD x = 1.85g cm–3 forZ = 4. The finalR factor for 1283 observed reflections is 0.046. The aluminum atom is bonded to the nitrogen atom of the thiocyanate ligand, where the Al-N bond length is 1.94(1) Å. The SCN is linear, and the CN-Al angle is 175(1) °. The cesium ion exhibits four contacts less than 3.60 Å: Cs C(thiocyanate) = 3.39(1) Å, Cs C(methyl) = 3.52(1) Å, Cs C.(methyl) = 3.56(1) Å, and Cs N = 3.575(9) Å. The closest Cs S is 3.772(3) Å.  相似文献   

14.
Crystals of C4H6N4O·H2O are orthorhombic:Pbca,a=16.721(2),b=4.242(1),c=18.293(2)Å,Z=8. The structure has been solved by direct methods and refined by full-matrix least-squares techniques toR=0.046 for 1252 unique reflections. The structure consists of approximately planar molecules of the 3(H)4-one tautomer. Delocalization of the ring and the C=O-electrons, and conjugation of the lone-pair electrons of the amine groups with the pyrimidinone nucleus are observed. The molecules are connected by O-HO, N-HN, and N-HO hydrogen bonds. The molecular structure clarifies the chemical properties of the compound.  相似文献   

15.
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) Å3,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.  相似文献   

16.
The preparation and X-ray crystal structures of two polymorphs of the antibacterial drug nitrofurantoin are reported. The -polymorph is triclinic, space groupP¯1 witha=6.774(1),b=7.795(1),c=9.803(2)Å, =106.68(1),=104.09(2), =92.29(1)°,Z=2. The-polymorph is monoclinic, space groupP21/n witha=7.840(5),b=6.486(1),c=18.911(6)Å,=93.17(3)°,Z=4. The nitrofurantoin molecules adopt the same, planar conformation in both polymorphs. Both crystal structures are built up from layers held together by van der Waals forces. In each polymorph, intralayer cohesion is effected by N-HO and C-HO hydrogen bonds, but their arrangements differ in the two crystals. The significance of the C-HO hydrogen bond, now known to occur in four modifications of nitrofurantoin, is discussed.  相似文献   

17.
The title compound has been prepared by the addition of fluoroboric acid to 18-crown-6 in toluene. The compound crystallizes in the triclinic space group P¯1 witha=7.341(2),b=8.364(2),c=10.631(3)Å,=71.48(2),=67.91(2), =67.94(2)°, andD c =1.44 g cm–3 forZ=1. The final conventionalR value was 0.079 based on 1575 observed reflections. The molecule resides on a center of inversion. The (H2O·HBF4) moieties are best viewed as fluoroboric acid monohydrate molecules hydrogen bonded to the crown ether, one above and one below the plane of the crown. The FO(water) hydrogen bond separation is 2.474(5)Å, and the O(crown)O(water) separations are 2.834(5) and 2.841(6) Å. The oxygen atoms of the crown ether are planar to 0.23 Å.  相似文献   

18.
The title compound C9H11NO2 is triclinic, space group P¯1, with the cell dimensionsa=7.022(1),b=7.476(2),c=8.957 (1) Å,=87.02(2),=110.88(1),=99.10(1)°,V=433.8(4) Å3,Z=2,M r =165.2,Do=1.27,Dx=1.26 mg/m3,F(000)=176,T=293 K,R=0.057 for 939 observed reflections. The molecules are packed as centrosymmetric hydrogen bonded dimers with an O-HO distance of 2.626(3) Å. The COOH group is rotated by 1.7(1)° about the exocyclic C(1)-C(7) bond out of the benzene ring plane. The molecules lie on (0 2-1) plane for which thed value is found to be 3.378 Å which is very close to the mean separation between the parallel packed benezene rings [3.347(4) Å]. The entire molecule is planar except for the two methyl groups attached to the nitrogen atom. The N atom is free from any binding of either type C-HN or O-HN.N. C. L. Communication No. 4699.  相似文献   

19.
Disarcosine hydrobromide, C6H15N2O4 +Br, crystallizes in the orthorhombic space groupPca21 with eight formula entities per unit cell of dimensionsa = 23.79,b = 6.18, andc = 15.40 Å, that is, two disarcosine molecules in the asymmetric unit. The structure was solved by the heavy-atom method using three-dimensional visually estimated X-ray data, and refined by the block-diagonal least-squares method to a finalR value of 0.11. The molecules are held together by a network of hydrogen bonds of the types N-H Br, N-H O, and O-H O.  相似文献   

20.
The title compound, l-(2,3-dideoxy-3-azido--D-erythro pentofuranos-1-yl)-5-chlorocytosine, crystallizes in the orthorhombic space groupP212121 witha=5.840(1),b=13.780(1),c=15.396(2)Å,Z=4. The structure was solved by direct methods and refined by full-matrix least-squares calculations to a finalR value of 0.033 for 1688 unique observed reflections. The N-glycosidic torsion angle has a value of –160.8(1)°, in the and range. The sugar pucker is 2 3 T withP=180(1)° and=34(1)°. The C4–C5 conformation is +sc with =50.8(2)°. The azido group is nonlinear and oriented trans to the C3–C4 bond. The molecular packing in the crystalline space is stabilized by N-HN, N-HO, O-HO hydrogen bonds and C-HO close contacts.  相似文献   

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