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1.
A. K. Das S. K. Mazumdar V. Bertolasi A. Van Aerschot 《Journal of chemical crystallography》1993,23(5):353-357
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
2.
The spectroscopic and X-ray investigation of the N-(2-phenylethyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are reported. The1H NMR spectra for the title structure and for the N-(p-methoxybenzyl) amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid are given. The N-(2-phenylethyl)amide of -(1,1-ethylenedioxy)-ethyl--hydroxybutyric acid, C16H23O4N, crustallizes in the monoclinic space groupP2
1/c witha=21.547(5),b=6.333(2),c=11.822(3) Å and =101.01(2)°. The dioxolane ring has a half-chair conformation with C2(O3)=2.4° and ||av=18.2°. The inconsiderable deviations from planarity of the six atoms of the amide group are caused mainly by twist around the C4–N1 bond and out-of-plane bending at the N1 atom ((C4–N1)=4°, XN =7°, Xc =0.4° ). The amide group plane is nearly coplanar with the phenyl ring. The molecules are connected by two intermolecular hydrogen bonds. 相似文献
3.
A. K. Das S. K. Mazumdar V. Bertolasi A. Van Aerschot 《Journal of chemical crystallography》1993,23(6):455-458
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
4.
J. Skoweranda M. Bukowska-Strzyzewska R. Bartnik W. Strzyżewski 《Journal of chemical crystallography》1990,20(2):117-121
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
5.
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
6.
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
7.
C20H30O3, M
r
=318.46, Monoclinic,P21,a=12.232(2) ,b=11.491(2) ,c=14.160(3) , =115.2°(3),V=1800.3(7) 3,Z=4,D
x
=1.18 Mg m–3, (CuK)=1.5418 , =5.3 cm–1,F(000)=696,T=298 K. FinalR=0.044 for 2645 reflections withI>2. The two crystallographically independent molecules in the unit cell adopt essentially similar conformations. The structure reveals atrans relationship between the hydrogen at C(9) and the methyl group at C(20). The stereochemistry at C(13) is S. Apart from van der Waals forces the structure is stabilized by hydrogen bonds. 相似文献
8.
Gregory H. Robinson Mark F. Self Samuel A. Sangokoya William T. Pennington 《Journal of chemical crystallography》1988,18(3):285-291
Reaction of an excess of trimethylaluminum with bis(diphenylphosphino)-methane in heptane affords the crystalline complex [A1(CH3)3]2[(C6H5)2PCH2P(C6H5)2]. The title compound crystallizes in the triclinic space group P¯1 with unit cell parametersa=10.053(6),b=11.017(6),c=15.908(8) Å,=85.58(4),=71.80(4), =77.49(4)°,V=1634(1) Å3, andD
c=1.07 g cm–3 forZ=2. Least-squares refinement based on 2924 observed reflection with intensitiesI3I) in the range 2.00245.0° converged atR=0.050 (R
w=0.067). The Al-P distances are 2.585(2) and 2.521(2) Å, and the P-C-P angle is 121.4(2)°. 相似文献
9.
J. E. Mulvaney L. Pang R. J. Cramer H. K. Hall Jr. 《Journal of chemical crystallography》1982,12(4):331-342
The crystal structure of 2,2-bis-1,3-dithiole dimethyl dicyanofumarate has been determined from a single-crystal X-ray study. The compound crystallizes in the monoclinic space groupP21/c with two complexes per unit cell of dimensionsa=11.075(2)Å,b=11.615(3)Å,c=6.623(4)Å, ==90.0°,=95.7(16)°, andV=847.6(9)Å3. The observed and calculated densities are 1.56 and 1.57 g cm–3 respectively. Full-matrix least-squares refinement using 404 reflections having 4°250° andI3(I) converged atR=0.0492 andR
w
=0.0614. Structural parameters in bond lengths and bond angles do not change to any observable extent when comparing the parent molecules to the complexed state. AnOrtep view along thec-axis shows the units to be arranged in segregated parallel stacks with a distance of 3.31 Å between layers.We are indebted to the US Army Research Office, Grant DAAG-29-77-G-0231, for support of the research and to Dr. J. H. Enemark and Dr. W. Setzer for their professional advice. 相似文献
10.
A. K. Das S. K. Mazumdar V. Bertolasi A. Van Aerschot 《Journal of chemical crystallography》1993,23(5):437-440
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
11.
The coordination chemistry of a series of 2,6- and 2,3-diarylpyrazines with copper(II) acetate is reported. The 2:2 coordination complexes formed between two 2,6-diarylpyrazines and copper(II) acetate are characterized by X-ray crystallography. The structure (2,6-bis(3,5-dimethylphenyl)pyrazine)copper(II) acetate acetonitrile solvate, (C48H52Cu2N4O8) (C2H3N) is triclinic, P 1, with a = 7.9685(10), b = 13.1893(16), c = 13.8267(17) Å, = 107.585(3)°, = 103.921(3)° and = 96.759(3)°. The structure of (2-(2,6-dimethylphenyl)-6-(3,5-dimethylphenyl)pyrazine)copper(II) acetate, C48H52Cu2N4O8, is monoclinic, P21/c, with a = 8.2196(7), b = 12.5174(11), c = 21.7325(19) Å and = 96.201(2)°. 相似文献
12.
J. Gabriel Garcia Yen-Hsiang Liu Frank R. Fronczek 《Journal of chemical crystallography》1996,26(9):607-613
The crystal structures of two conjugated ene-yne derivatives of thiophene are described, 2,5-di-(trimethylsilylethynyl)-3,4-dibromothiophene (1), is triclinic P
witha=6.3281(4)Å,b=9.7421(6)Å,c=16.3669(9)Å; =80.516(5)°, =84.810(5)°, =74.072(5)°,Z=2,R=0.054; 2,3,4,5-tetra(trimethylsilylethynyl)thiophene (2), is monoclinic, P21/c with a=20.928(2)Å b=5.852(1)Å,c=23.907(2)Å; =100.245(6)°,Z=4,R=0.049. The ethynylic C atoms of both compounds lie near the thiophene plane, with deviations in the range 0.010(3)–0.455(4)Å. The phenyl groups of2 form a dihedral angle of 13.0(4)°. 相似文献
13.
W. Kwiatkowski J. Karolak-Wojciechowska M. W. Wieczorek 《Journal of chemical crystallography》1988,18(5):517-523
C20H22O4,M
r
=326.39, triclinic,P¯1,a=10.365(2),b=11.383(2),c=8.461(1) Å, =103.60(1),=104.44(1), =105.23(1)°,Z=2, (CuK)=1.54178 Å;R=0.0633 for 1940 reflections. The results of the X-ray analysis have shown that the ethyl carboxylate substituent is oriented. The geometry of the main skeleton of the molecule has not revealed any significant differences in the present compound and in the case of the epimeric molecule. 相似文献
14.
Jun Wang Feng-Li Bei Xing-You Xu Xu-Jie Yang Xin Wang 《Journal of chemical crystallography》2003,33(11):845-849
A new complex has been synthesized and characterized by elemental analysis, IR, TGA, and single-crystal X-ray analysis. The crystal is orthorhombic and the space group is chiral (P212121) with a = 6.620(3) Å, b = 17.300(4) Å,, c = 5.450(1) Å,, = 90°, = 90°, = 90°, z = 4. In the crystal lattice, the molecules create a two-dimensional network structure through hydrogen bonds. The C–HO intermolecular hydrogen bonds connect the title complex to form a supermolecular structure. 相似文献
15.
V. Ferretti P. Gilli V. Bertolasi G. Spalluto G. Gilli 《Journal of chemical crystallography》1993,23(3):195-201
(3(Z),4,6a,9a,9b)-(±)-3a,4,6a,7,8,9,9a,9b-octahydro-4,7,7, 9b-tetramethyl-3a-[3-(methoxymethyloxy)-3-methyl-1-butenyl]-5H-naphto[1,8-de]-1,3-dioxin-6-one (I), C22H36O5,M
r=378.51, monoclinic,P21/n,a=6.330(1),b=14.576(2),c=22.837(2)Å,=93.04(1)°,V=2104.1(2)Å3,Z=4,D
c=1.19 Mg/m3, (MoK)=0.71069Å,=0.8 cm–1,F(000)=832,T=298 K,R=0.054 for 1971 observed reflections; (7a,10a,10b,12)-(±)-7a,9, 10,10a,10b,11,12,12a-octahydro-2,2,10,10,10b,12a-hexamethyl-2H,8H-1-benzopyrano[4a,5,6,-de][1,3,2]-benzodioxin-11-one (II), C20H29O4,M
r=334.5, triclinic,P-1,a=10.595(2),b=12.152(1),c=8.073(1)Å,=106.53(1),=105.65(1), =66.29(1)°,V=897.9(2)Å3,Z=2,D
c=1.24 Mg/m3, (MoK)=0.71069Å,=0.8 cm–1,F(000)=362,T=298 K,R=0.046 for 2848 observed reflections; (7a,10a,10b,12, 12a)-(±)-7a,9,10,10a,10b,11,12,12a-octahydro-2,2,10,10,10b,12a-hexamethyl-2H,8H-1-benzopyrano[4a,5,6-de][1,3,2]-benzodioxin-11, 12-diol (III), C20H32O5 (two molecules in the asymmetric unit),M
r=352.2, triclinic,P-1,a=12.948(3),b=13.615(3),c=12.197(4)Å,=101.16(2),=111.88(2), =69.48(2)°,V=1863.8(9)Å3,Z=2,D
C=1.26 Mg/m3,(MoK)=0.71069 Å,=0.8 cm–1,F(000)=768,T=298 K,R=0.060 for 4570 observed reflections; 4-acetoxy-4-[[(4a,5,8a)-(±)-hexahydro-4a,6,6-trimethyl-4H-1,3-benzodioxin-4-one]-5-yl]butan-2-one (IV), C17H26O6,M
r=326.4, monoclinic,P21/c,a=10.495(2),b=12.050(2),c=14.216(2)Å,=108.51(1)°,V=1704.8(5)Å3,Z=4,D
c=1.27 Mg/m3,(MoK)=0.71069 Å,=0.9 cm–1,F(000)=704,T=298 K,R=0.049 for2455 observed reflections; (3a,4,5,6,6a,9a,9b)-(±)-4,5-epoxy-decahydro-3, 3a-dihydroxy-2-ethoxy-4,7,7,9b-tetramethyl-naphto-[1,8-bc]-pyran-6-ol-acetate (V), C20H32O7,M
r=383.5, monoclinic,C2/c,a=10.353(2),b=17.975(3),c=21.188(3)Å,=91.29(1)°,V=3942(1)Å3,Z=8,D
c=1.29 Mg/m3,(MoK)=0.71069 Å,=0.8 cm–1,F(000)=1664,T=298 K,R=0.051 for 2120 observed reflections. We report here the complete structures of four decalin derivatives (compoundsI, II, III, V) and one related compound (compoundIV) synthetized in order to find an efficient synthetic approach for the natural productforskolin. 相似文献
16.
The structure of the title compound has been confirmed by an X-ray diffraction analysis, and refined by full-matrix least squares. The crystals are mono-clinic:a=9.171(3),b=25.176(15)c=9.192(3) Å,=117.08(3)°,Z=4,D
x
=1.976g cm–3,=2.66mm¯1, space groupP21/n (No. 14). The finalR value is 5.7%. Interatomic distances and bond angles are compared with those reported in related molecules.The preferred name of this compound according to the IUPAC rules is
3-[11–2-bis(trifluoromethyl)vinylene]-
3-carbonyl-tris (-cyclopentadienyl)-triangulo-tricobalt. 相似文献
17.
Dianne R. Bond Luigi R. Nassimbeni Fumio Toda 《Journal of chemical crystallography》1989,19(5):847-859
The structures of the 12 molecular complexes oftrans-9,10-dihydroxy-9,10-diphenyl-9,10-dihydroanthracene with 4-methylcyclohexanone (1) and with 2-methylcyclohexanone (2) have been determined by X-ray crystallography. The crystal data are as follows: Compound (1):P22/c,a=8.838(2) Å,b=8.92(1) Å,c=20.879(8)=Å,=98.67(2)°,V=1627(2) Å3,Z=2 andR=0.062 for 2201 unique MoK reflections; Compound (2):P¯1,a=8.917(3) Å,b=9.900(2) Å,c=11.250(4) Å,a=68.72(2)°,=64.39(3)°, =74.86(2)°,V=828.1(5) Å3,Z=1 andR=0.098 for 2563 unique reflections. Both inclusion compounds exhibit O-HO=C hydrogen bonding interactions. The thermal properties of these compounds have been characterized by DTA and TGA thermograms. 相似文献
18.
V. Busetti J. A. Mayoral C. Cativiela D. Ajò F. De Zuane 《Journal of chemical crystallography》1990,20(6):545-550
The crystal and molecular structure of the methyl ester of-cyanocinnamic acid [(E)-methyl--cyanocinnamate] has been determined from three-dimensional X-ray data. C11H9NO2 is monoclinic, space groupC2/c,Z=8,a=12.386(2),b=8.237(1),c=19.320(2) Å,=98.49(5)°. The He(I) and He(II) photoelectron (PE) spectra of (E)-methyl--cyanocinnamate are presented and discussed in comparison with those of previously investigated molecules, within a comprehensive investigation of the electronic structure of,-dehydroamino acid derivatives and related compounds. 相似文献
19.
Simon G. Bott D. Rajagopal Alan P. Marchand Kaipenchery A. Kumar 《Journal of chemical crystallography》1996,26(6):425-428
The compound crystallizes in the triclinic space group,
, witha=6.7702(4),b=7.0180(4),c=9.1960(7) Å, =92.457(6), =96.150(6), =93.444(5)°, andZ=2. The structure contains a rather short intramolecular H...H contact of 2.26(4) Å. 相似文献
20.
Seik Weng Ng Abdul Hamid Othman Sri Nurestri Abdul Malek 《Journal of chemical crystallography》1994,24(5):331-335
1-(2-Hydroxyphenyl)-3-phenyl-1,3-propanedione crystallizes in the triclinic space group
(a=5.4233(5),b=13.910(1),c=17.036(1) Å, =68.311(6), =80.854(7), =78.760(8)°) as two independent enolic tautomers in which the hydroxyl and phenolic protons are hydrogen bonded to the ketonic oxygen atom. The structure was refined toR=0.039 for 2085I3(I) reflections. 1-(1,3-Benzodioxol-5-yl)-3-(2,4-dimethoxyphenyl)-1,3-propanedione, which belongs to the triclinic
space group (a=7.3990(7),b=8.1239(5),c=14.004(1) Å, =86.673(6). =88.574(7), =64.885(7)°) also exists in the enolic form. The structure was refined toR=0.040 for 1564I3(I) reflections. 相似文献