Molecular conformation of 2′-deoxy-3′,5′-di-O-acetyl adenosine. Crystal structure and high resolution proton nuclear magnetic resonance investigations

1987 ◽  
Vol 65 (2) ◽  
pp. 326-331 ◽  
Author(s):  
Leo H. Koole ◽  
Henk M. Buck ◽  
Jan A. Kanters ◽  
Arie Schouten
Keyword(s):  
Crystal Structure ◽  
Molecular Conformation ◽  
Proton Nuclear Magnetic Resonance ◽  
Solution Conformation ◽  
Orthorhombic Space Group ◽  
One Dimensional ◽  
X Ray ◽  
H Nmr ◽  
Conformational Preferences ◽  
Cell Dimensions

2′-Deoxy-3′,5′-di-O-acetyl adenosine crystallizes in the orthorhombic space group P212121, and the cell dimensions are a = 7.768(1) Å, b = 12.890(1) Å, c = 15.495(1) Å; Z = 4 molecules per cell. Least-squares refinement converged at R = 0.054 for 1752 observed reflections. The adenine bases are linked via N6—H … N1 and N6—H … N7 hydrogen bonds, in such a way that infinite one-dimensional chains are formed. Comments are made on the fact that this structure is entirely different from the parallel dimer that was found for 3′,5′-di-O-acetyl thymidine. Furthermore, the conformational preferences of the title compound in aqueous solution have been determined with 300- and 500-MHz 1H nmr. It is found that the X-ray structure and the solution conformation are essentially similar, except for the C4′—C5′ conformation, that is γ− in the solid state, and predominantly γ+ in solution.

Molecular conformation of 2′-deoxy-3′,5′-di-O-acetyl guanosine. Crystal structure and high resolution proton nuclear magnetic resonance investigations

1988 ◽  
Vol 66 (10) ◽  
pp. 2634-2639 ◽  
Author(s):  
Leo H. Koole ◽  
Henk M. Buck ◽  
Jan A. Kanters ◽  
Arie Schouten
Keyword(s):  
Molecular Conformation ◽  
Proton Nuclear Magnetic Resonance ◽  
Solution Conformation ◽  
Planar System ◽  
Equal Distribution ◽  
Triclinic Space Group ◽  
X Ray ◽  
H Nmr ◽  
Conformational Preferences ◽  
Cell Dimensions

2′-Deoxy-3′,5′-di-O-acetyl guanosine crystallizes in the triclinic space group [Formula: see text], and the cell dimensions are a = 8.643(1) Å, b = 10.122(1) Å, c = 10.391(1) Å, α = 87.04(1)°, β = 73.58(1)°, γ = 72.37(1)°, V = 830.4(2) Å3; Z = 2 molecules per cell. Least-squares refinement converged at R = 0.031 for 3450 observed reflections. The asymmetric unit consists of two independent molecules. The guanine bases are linked via N(1)—H … N(7) and N(2)—H … O(6) hydrogen bonds to form a virtually planar system. Moreover, the conformational preferences of the title compound in DMSO-d6 solution have been determined with 300 MHz 1H NMR. It is found that the X-ray structure and the solution conformation are essentially similar. The C(4′)—C(5′) linkage resides in the gauche+ (g+) or trans (t) rotamers in the solid state, while an approximately equal distribution over g+, t, and gauche− is found in solution.

Crystal structure of the anticancer drug carmustine determined by X-ray powder diffraction

2021 ◽  
pp. 1-3
Author(s):  
Carina Schlesinger ◽  
Edith Alig ◽  
Martin U. Schmidt
Keyword(s):  
Crystal Structure ◽  
Anticancer Drug ◽  
Powder Diffraction ◽  
Room Temperature ◽  
Powder Diffraction Data ◽  
Orthorhombic Space Group ◽  
Commercial Sample ◽  
One Dimensional ◽  
X Ray ◽  
Hydrogen Bond Pattern

The structure of the anticancer drug carmustine (1,3-bis(2-chloroethyl)-1-nitrosourea, C5H9Cl2N3O2) was successfully determined from laboratory X-ray powder diffraction data recorded at 278 K and at 153 K. Carmustine crystallizes in the orthorhombic space group P212121 with Z = 4. The lattice parameters are a = 19.6935(2) Å, b = 9.8338(14) Å, c = 4.63542(6) Å, V = 897.71(2) ų at 153 K, and a = 19.8522(2) Å, b = 9.8843(15) Å, c = 4.69793(6) Å, V = 921.85(2) ų at 278 K. The Rietveld fits are very good, with low R-values and smooth difference curves of calculated and experimental powder data. The molecules form a one-dimensional hydrogen bond pattern. At room temperature, the investigated commercial sample of carmustine was amorphous.

The reaction of chloro(triphenylphosphine)gold(I) with 1-methylthymine

1987 ◽  
Vol 65 (7) ◽  
pp. 1568-1575 ◽  
Author(s):  
R. Faggiani ◽  
H. E. Howard-Lock ◽  
C. J. L. Lock ◽  
M. A. Turner
Keyword(s):  
Aqueous Methanol ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
X Ray Crystallography ◽  
H Nmr ◽  
Cell Dimensions ◽  
Cell Data ◽  
Unit Cell Data ◽  
Related Compounds ◽  
C Nmr

1-Methylthyminato-N3-triphenylphosphinegold(I) was prepared by reacting chloro(triphenylphosphine)gold(I) with 1-methylthymine in aqueous methanol at pH 11. The product was examined by X-ray crystallography and was found to have the orthorhombic space group C2221 (no. 20) with cell dimensions a = 12.760(7) Å, b = 11.530(2) Å, c = 31.893(5) Å, and eight formula units in the unit cell. Data were collected with use of MoKα radiation and a Syntex P21, diffractometer. The crystal structure was determined by standard methods and refined to R = 0.112 and Rw = 0.076 on the basis of 4760 unique reflections. Bond lengths and bond angles are normal. Packing in the crystal lattice is dominated by the triphenylphosphine rings which arrange roughly as blades of a propellor and are the source of the crystal's chirality. The title and related compounds were also examined by 1H nmr, 13C nmr, and vibrational spectroscopy.

Complexes of methylmercury(II) with 1-methylcytosine and crystal structure of μ-(1-methylcytosinato-N3,N4)bis(methylmercury(II)) nitrate

1981 ◽  
Vol 59 (15) ◽  
pp. 2290-2297 ◽  
Author(s):  
Leonardo Prizant ◽  
Roland Rivest ◽  
André L. Beauchamp
Keyword(s):  
Crystal Structure ◽  
Amino Group ◽  
Nitrate Salt ◽  
Acidic Media ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
H Nmr ◽  
R Factor ◽  
Nmr Data ◽  
Solid Complexes

Two types of solid complexes are isolated by reaction of CH3HgX (X = NO3 and ClO4) with 1-methylcytosine (MCy). The CH3Hg+ ion is probably bonded to N(3) in the [CH3Hg(MCy)]X compounds. Mercury binding to N(3) and the deprotonated amino group in [(CH3Hg)2(MCy—H)]X is confirmed by X-ray work on the nitrate salt. The crystals are orthorhombic, space group Pbca, with a = 12.014, b = 13.573, c = 16.353 Å, and Z = 8. The structure was refined on 962 independent reflections to an R factor of 0.038. The CH3Hg+ groups are arranged in a syn configuration and the angles around the mercury-bonded nitrogen atoms are severely distorted to prevent short Hg … Hg contacts. N(3)-coordination in the 1:1 complexes introduces minor changes in the infrared spectra, but the substitution of an amino proton in the 1:2 compounds produces important modifications. 1H nmr data in DMSO-d6 are reported for both types of compounds. This work emphasizes the important acidity enhancement experienced by the amino protons upon initial coordination to N(3), which facilitates further reaction of CH3Hg+ by proton displacement even in acidic media.

scholarly journals Pressure-induced polymorphism in cyclopropylamine

2005 ◽  
Vol 61 (6) ◽  
pp. 717-723 ◽  
Author(s):  
Patricia Lozano-Casal ◽  
David R. Allan ◽  
Simon Parsons
Keyword(s):  
Crystal Structure ◽  
Crystal Packing ◽  
Hirshfeld Surface ◽  
Amino Group ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Graph Set ◽  
Unit Cell Dimensions

The crystal structure of cyclopropylamine at 1.2 GPa has been determined by X-ray diffraction methods. The structure of this phase is orthorhombic, space group Pbca and the unit-cell dimensions are a =  5.0741 (10), b  =  9.7594 (10) and c  =  13.305 (2) Å. Only one of the two H atoms of the amino group actively participates in the formation of the hydrogen-bonded chains, C(2) in graph-set notation, which lie parallel to the crystallographic a axis. Additionally, the topology of the crystal packing is studied using both Voronoi–Dirichlet polyhedra and Hirshfeld surface analyses for the low-temperature and the high-pressure structures of cyclopropylamine and the results are compared.

The preparation, X-ray crystal structure, and spectroscopic characterization of pentafluorophenyl-bis(pentafluorophenylthio)sulfonium hexafluoroarsenate, [(C6F5S)2SC6F5][AsF6]

1998 ◽  
Vol 76 (7) ◽  
pp. 1050-1059 ◽  
Author(s):  
Scott Brownridge ◽  
T Stanley Cameron ◽  
Jack Passmore ◽  
Gabriele Schatte ◽  
George W Sutherland
Keyword(s):  
Crystal Structure ◽  
Raman Spectroscopy ◽  
Room Temperature ◽  
Spectroscopic Characterization ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
Cell Dimensions ◽  
Ft Raman Spectroscopy ◽  
Ft Raman

Pentafluorophenyl-bis(pentafluorophenylthio)sulfonium hexafluoroarsenate, [(C6F5S)2SC6F5][AsF6], was prepared by the reaction of (C6F5)2S2 and AsF5 in liquid SO2 at room temperature. The compound has been characterized by single-crystal X-ray and powder diffraction, and IR and FT-Raman spectroscopy. Crystals of [(C6F5S)2SC6F5][AsF6] are orthorhombic, space group P212121 (cell dimensions measured at room temperature in brackets): a = 13.132(3) [13.157(2)] Å, b = 21.477(4) [21.575(3)] Å, c = 8.770(2) [8.775(1)] Å, α = ß = γ = 90.00°; V = 2473.3(9) Å3, Z = 4, temperature = 181 ± 1 K. The structure consists of [AsF6]- anions and [(C6F5S)2SC6F5]+ cations that have a different structure than the related [X2MMMX]+ cations (M = S, Se; X = Cl, Br), which contain a trichalcogen chain with a pronounced chalcogen-chalcogen bond alternation. Ab initio calculations suggest the observed [(C6F5S)2SC6F5]+ geometry is due to steric and solid state effects. Comparison of the Raman spectra of [(C6F5)S2SC6F5][AsF6], [Cl2SSSCl][AsF6], and [(CH3)2ClS3]+ implies that [(CH3)2ClS3]+ has a structure with equal sulfur-sulfur distances, and therefore the structure is likely [(CH3S)2SCl]+ and probably not the previously reported [(CH3)2SSSCl]+.Key words: [R3X3]+ cations, X-ray crystal structure, FT-Raman spectroscopy, [(C6F5S)2SC6F5]+, pentafluorophenyl-bis(pentafluorophenylthio)sulfonium cation, hexafluoroarsenate.

Crystal Structure of an Ammonium Dithiocyanatocuprate(I) Complex with 18-Crown-6, [NH4(18-Crown-6){Cu(NCS)2}] Obtained from Zero Valent Metal

1997 ◽  
Vol 52 (11) ◽  
pp. 1311-1314 ◽  
Author(s):  
Julia A. Manskaya ◽  
Volodimir N. Kokozay ◽  
Konstantin V. Domasevitch
Keyword(s):  
Crystal Structure ◽  
Direct Method ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
One Dimensional ◽  
X Ray ◽  
X Ray Crystallography ◽  
A Direct Method

The new macrocyclic dithiocyanatocuprate(I) complex [NH4(18-crown-6){Cu(NCS)2}] has been prepared using a direct method of interaction and characterized by X-ray crystallography (orthorhombic, space group Cmc21, with a = 12.453(2), b = 21.650(4), c = 8.151(2) Å, V = 2197.6(8) Å3, Z = 4 , R1 (F) = 0.054; wR2(F2) = 0.141 for 972 unique reflections with I > 2σ(I) and R1(F) = 0.082; w/?2(F2) = 0.210 for all 1098 unique reflections). The lattice comprises complex cations [NH4(18-crown-6)]+ and infinite polymeric anions [Cu(NCS)2]- of a one-dimensional zig-zag structure. The copper atoms adopt three-fold coordination [CuN2S] (Cu-N 1,89( 1), 1,90( 1) Å; Cu-S 2.278(4) Å).

Synthesis and structural study of aminals derived from 8-aminoquinoline and 1-aminonaphtalene

1987 ◽  
Vol 65 (4) ◽  
pp. 687-692 ◽  
Author(s):  
Enrique Galvez ◽  
Isabel Iriepa ◽  
Antonio Lorente ◽  
Jose Miguel Mohedano ◽  
Feliciana Florencio ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Carbon Atom ◽  
Mass Spectra ◽  
The Other ◽  
Reaction Conditions ◽  
Schiff’S Base ◽  
Triclinic Space Group ◽  
X Ray ◽  
H Nmr ◽  
Cell Dimensions

Reaction of 8-aminoquinoline with pyridine-2-carboxaldehyde (2), pyridine-3-carboxaldehyde (3), pyridine-4-carboxaldehyde (4), and benzaldehyde (5) yields the corresponding aminals or Schiff's bases according to reaction conditions; analogous results are obtained from the reaction of 1-amino-naphtalene with pyridine-2-carboxaldehyde (6). On the other hand, reaction of 8-aminoquinoline with thiophene-2-carboxaldehyde or pyrrole-2-carboxaldehyde yields neither the aminal nor the Schiff's base. Crystals of 4 (C24H19N5) belong to the triclinic space group [Formula: see text]. Cell dimensions are a = 11.547(3), b = 11.759(2), c = 15.687(5) Å, α = 98.50(2)°, β = 101.61(2)°, γ = 107.28(2)°, V = 1942.6(9) Å3. Final R = 0.077 and Rw = 0.064; 3160 reflections were observed. The ir, 1H nmr of 2–6, the mass spectra of 4 and 5 and the X-ray analysis of 4 are described and discussed. Preparative features, ir, 1H nmr, analyses and crystal structure indicate that the formation of 2–6 are governed mainly by the nucleophilicity at the aldehyde carbon atom and the existence of the hydrogen bonds in the aminal.

Conformation of methyl 3,6-dideoxy-α-D-arabino-hexopyranoside, the immunodominant sugar of Salmonella serogroup D1: crystal structure, 1H nmr analysis, and semi-empirical calculations

1985 ◽  
Vol 63 (3) ◽  
pp. 739-744 ◽  
Author(s):  
George I. Birnbaum ◽  
David R. Bundle
Keyword(s):  
Minimum Energy ◽  
Direct Methods ◽  
Anomeric Effect ◽  
Pyranose Ring ◽  
Hydrogen Atoms ◽  
Orthorhombic Space Group ◽  
X Ray ◽  
H Nmr ◽  
Cell Dimensions ◽  
Semi Empirical

Methyl 3,6-dideoxy-α-D-arabino-hexopyranoside (methyl tyveloside) crystallizes in the orthorhombic space group P212121 and the cell dimensions are a = 7.478(1), b = 7.933(1), c = 14.064(1) Å. X-ray intensity data were measured with a diffractometer and the structure was solved by direct methods. Least-squares refinement, which included all hydrogen atoms, converged at R = 0.038. The pyranose ring exists as an almost perfect 4C1 chair and the conformation adopted by the glycosidic methyl group is in agreement with the requirements of the exo-anomeric effect. Both acetal oxygen atoms act as hydrogen-bond acceptors, and the [Formula: see text] bond distances are in agreement with this feature. The 1H nmr spectrum shows that the conformation of the pyranose ring in aqueous solution is indistinguishable from that in the crystal. The minimum energy conformation of a pentasaccharide fragment of a Salmonella O-antigen, calculated with tyvelose coordinates obtained by bond modification, is in good agreement with the conformation which was calculated with tyvelose coordinates obtained from the X-ray analysis.

scholarly journals Die Kristallstruktur des Kalium-tri-isocyanatocadmats KCd(NCO)3 / The Crystal Structure of KCd(NCO)3

1975 ◽  
Vol 30 (1-2) ◽  
pp. 19-21 ◽  
Author(s):  
Gerhard Thiele ◽  
Peter Hilfrich
Keyword(s):  
Crystal Structure ◽  
X Ray Diffraction ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
X Ray ◽  
Cell Dimensions

The crystal structure of KCd(NCO)3 has been determinated by threedimensional X-ray diffraction. The crystals are orthorhombic, space group Pnma with the cell dimensions a = 999.3 pm, b = 367.1 pm and c = 1835.4 pm. The cadmium atoms are surrounded octahedrally by six N-atoms. As in the KCdCl3-structure N-bridged double chains along the c-axis are formed which are linked together by the potassium atoms.

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