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 inclusion phenomena and macrocyclic chemistry 6 (1988), S. 135-142 
    ISSN: 1573-1111
    Keywords: Permethylated α-cyclodextrin ; induced circular dichroism ; inclusion complex ; host-guest interaction
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The complex formation of hexakis (2,3,6-tri-O-methyl)-α-cyclodextrin with substituted benzenes has been investigated by circular dichroism (CD) spectroscopy. The sign and shape of the CD spectra markedly differ from the spectra of corresponding α-cyclodextrin complexes because of the distorted conformation of the host molecule and/or the difference in the geometry of the host-guest interaction. Enthalpy and entropy changes of the complex formation are determined by using the CD band intensities measured at various temperatures and host concentrations. Negative values of ΔH and ΔS indicate that the hydrophobic interaction is not the major driving force for the complex formation. The guest molecule is suggested to be tightly bound within the host cavity through the induced-fit conformational change of the host molecule.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inclusion phenomena and macrocyclic chemistry 6 (1988), S. 443-460 
    ISSN: 1573-1111
    Keywords: Methylated cyclodextrin ; inclusion complex ; host-guest interaction ; chiral recognition ; crystal structure ; Flurbiprofen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Hepatakis(2,3,6-tri-O-methyl)-β-cyclodextrin (TM-β-CDx) forms crystalline complexes with (R)-Flubiprofen (R-FP), C63H112O35C15H13O2F·H2O, and (S)-Flurbiprofen (S-FP), C63H112O35C15H13O2F. The crystal structures were determined by X-ray analysis. Crystals of both compounds are orthorhombic and the space group isP212121 with cell dimensions:a=15.092(2),b=21.714(3), andc=28.269(4) Å for theR-FP complex, anda=15.271(2),b=21.451(3) andc=27.895(3) Å for theS-FP complex. The macrocyclic ring of TM-β-CDx is markedly distorted because of the inability to form intramolecular hydrogen bonds and the steric hindrance involving methyl groups. In both complexes, the phenyl group is inserted into the host cavity from the O(2), O(3) side, which is wider than the O(6) side. The biphenyl moiety ofR-FP is fixed in theR-configuration within the host cavity. The phenyl group ofS-FP is disordered, andR-andS-configurations are statistically distributed with equal probability. TM-β-CDx molecules are stacked along theb axis to form a column structure. The TM-β-CDx molecule is laterally shifted with respect to the column axis, and a half of the guest molecule protrudes outside from the crevis of the column. The carboxyl group ofR-FP forms a hydrogen bond with water located outside the host cavity, while the carboxyl group ofS-FP is hydrogen-bonded to an oxygen atom of an adjacent TM-β-CDx.
    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...