ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of chemical crystallography 19 (1989), S. 507-512 
    ISSN: 1572-8854
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Crystal structure of the title compound belonging to the group ofα-acylimino derivatives of sulfur(II) compounds has been determined by X-ray structure analysis. The crystals are monoclinic, P21/c,a=11.210(2),b=8.197(1),c=13.659(2) Å,β=102.36(2)°,V=1226.0(3) Å3,Z=4,D x =1.61 g cm−3, λ(MoKα)=0.71069 Å,μ=6.3 cm−1. The structure has been refined to a finalR value of 0.035 for 1401 observed reflexions. The molecule is nearly planar with symmetrym. The title compound contains a very short intramolecular C=O⋯S contact of 2.328(3) Å, suggesting a ‘bond-non-bond’ resonance interaction.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1572-8854
    Keywords: Tautomerism ; hydrogen bonding ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Crystals consisting of two distinct chemical entities, tautomers of each other, in exact 1∶1 ratio, have been obtained and their structure determined by X-ray analysis. The crystals of C9H11N3·C9H11N3 are monoclinic,P21/c,a=15.674(3),b=17.085(3),c=13.758(3)Å, β=90.78(2)°,Z=8. There are two hydroxylamine and two aminonitrone molecules in the asymmetric unit. Hydrogen bonds connect those molecules into chiral layers. Layers of opposite chirality alternate andthe crystal is centrosymmetric as a whole. Within those layers chains of tautomers joined by very strong O−H... O and strong N−H... N bonds can be recognized. Proton transfer along those chains with simultaneous rearrangement of π-bonds within the molecules would result in interconversion of tautomers and would affect chirality of the layer.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 20 (1994), S. 53-71 
    ISSN: 1573-1111
    Keywords: Lithium ionophores ; podand ; dicyclohexylamides ; Li-complex ; crystal structure ; X-ray analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The influence of structure and lipophilicity of dicyclohexylamides on the lithium selectivity in membrane electrodes is discussed. The crystal structures of the triamide podand1 and its complex with LiBr1b has been determined by X-ray analysis. Crystal data for ligand1: C48H83O6N3, triclinic,P1,a=10.749(2),b=12.097(3),c=19.123(6)Å, α=95.76(2),β=80.06(2), γ=100.27(2)0,V=2403(1) Ã3,Z=2. Crystal data for the lithium complex1b: C48H83O6N3·LiBr·x C2H5OH, monoclinic,P2 1/c,a=21.297(6),b=16.316(8),c=19.450(4) Å,β=110.87(2)0,V=6315(3) Å3,Z=4. In the complex the ligand adopts a conformation in which oxygen binding sites surrounding the Li+ cation form a slightly distorted trigonal prism.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 22 (1995), S. 187-201 
    ISSN: 1573-1111
    Keywords: Inclusion compounds ; gossypol ; crystal structure ; hydrogen bonds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The crystal structure of the inclusion compound of gossypol withn-valeric acid as a guest molecule has been determined by X-ray structure analysis. The crystals of C30H30O8·(C5H10O2)2, are triclinic, space group $$P\bar 1$$ ,a=6.912(2),b=14.506(3),c=19.387(4) Å, α=78.85(2)°, β=83.92(3)°, γ=86.78(3)°V=1895(1) Å3,Z=2,D x=1.267 g cm−3, μ (CuK α)=0.768 mm−1,T=292 K. The structure has been solved by direct methods on intensity data collected for a twinned crystal and refined to the finalR value of 0.062 for 1606 observed reflections and 470 refined parameters. Gossypol-n-valeric acid (1/2) coordinato-clathrate is not isostructural with any of the previously investigated gossypol inclusion compounds but shows some structural similarities to gossypol-acetic acid (1/1). The host and one of the carboxylic acid molecules are connected via hydrogen bonds into molecular assemblies of a column type which are further bonded to centrosymmetric dimers of the secondn-valeric acid molecule. In effect, host and guest molecules are assembled into layer-type H-bonded aggregates. Structural features common to gossypol-n-valeric acid (1/2) and other earlier reported gossypol inclusion compounds are discussed.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 17 (1994), S. 365-376 
    ISSN: 1573-1111
    Keywords: Gossypol ; inclusion compounds ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The crystal structure of a compound obtained in a condensation reaction of (±)-gossypol with (R)-(+)-phenylethylamine has been determined by X-ray structure analysis. The crystals of C46H48O6N2·(C4H8O2)2 are monoclinic, space groupP21,a=21.243(3),b=8.666(1),c=28.651(4) Å, β=108.24(1)0,V=5009(3) β3,Z=4,D x=1.195 g cm−3, μ(CuK α)=0.66 mm−1,T=292 K. The structure has been solved by direct methods and refined to the finalR value of 0.091 for 4290 observed reflections and 1049 parameters. There are two diastereoisomeric molecules of the host and four solvent molecules in the asymmetric unit. The host molecules are H-bonded into chains with diastereoisomeric molecules alternating along the chain. The fact that the host prefers the association mode in which molecules with a different configuration of the 2,2′-binaphthyl moiety are H-bonded explains why separation of diastereoisomeric diaminogossypols by fractional crystallization has been unsuccessful. The 1,4-dioxane molecules are accommodated in infinite channels but only every second guest molecule in a channel is H-bonded to the host.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 22 (1995), S. 211-219 
    ISSN: 1573-1111
    Keywords: (R, R)-Tartaric acid derivatives ; host-guest compounds ; crystal structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract TheO, O′-dibenzoyl derivative of (R, R)-tartaric acid shows a good inclusion ability for diethyl and di-n-propol ethers. The two crystalline inclusion compounds have 1:1 stoichiometry and reveal isomorphous structures. Hydrogen bonded host molecules form chains running along thez axis of the unit cell and guest molecules join to these chains by short O−H...O hydrogen bonds. Hydrogen bonding in the crystals is characterized by a C(7)D first-order network. The ether molecules are in a fully extended conformation. They are accommodated in channel-like voids running along thex axis. Atomic displacement parameters are significantly larger for diethyl ether than for the di-n-propyl ether molecule reflecting less dense packing for this inclusion compound.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 37 (2000), S. 155-169 
    ISSN: 1573-1111
    Keywords: inclusion compounds ; cholic acid ; benzophenone ; chiral conformations
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The 2 : 1 cholic acid – benzophenone clathratecrystallizes in the space group P2_1 withthe unit-cell parameters a = 25.498(6),b = 7.942(1), c = 28.309(6) Å,β = 101.85(2)°. There are four symmetricallyindependent host molecules in the unit cell: two ofthem with the steroidal side chain assuminggauche and the remaining two with the side chain in thetrans conformation. Pairs of the host moleculesadopting similar conformations alternate along the[201] direction of the bilayer. The guestmolecules are accommodated in two crystallographicallyindependent but topologically similar channelsrunning parallel to [010]. Benzophenone molecules aredisordered and included in each channel in twodifferent conformations.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...