			Home About us Contact

Molecular Capsules (molecular + capsule)

Distribution by Scientific Domains

Chemistry	100%

Selected Abstracts

ChemInform Abstract: Vibrational Spectroscopy of a Tetraureidocalix[4]arene Based Molecular Capsule.

CHEMINFORM, Issue 17 2002
Joerg Dormann
Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source]

Noncovalent Isotope Effect for Guest Encapsulation in Self-Assembled Molecular Capsules

CHEMISTRY - A EUROPEAN JOURNAL, Issue 4 2010
Takeharu Haino Prof.
No abstract is available for this article. [source]

pH-Controlled Molecular Switches and the Substrate-Directed Self-Assembly of Molecular Capsules with a Calix[4]pyrrole Derivative

CHEMISTRY - A EUROPEAN JOURNAL, Issue 36 2008
Grazia Cafeo Dr.
Abstract 10,,20,-Bis(4-nitrophenyl)calix[4]pyrrole (1) forms 1:1 complexes with anions of selected aromatic hydroxy acids in which the host orientation within the guest is controlled by a change in the pH,value. Some bis-anionic guests, including those obtained from 4-hydroxybenzoic acid, 1,4- and 1,3-benzenedicarboxylic acids, induce the self-assembly of molecular capsules involving two molecules of the receptor. 1H,NMR data and solid-state structures of the 1:1 complex of 1 with p -C6H4(COOH)(COO,)+NMe4 and the 2:1 capsule [(1)2m -C6H4(COO,)2(+NMe4)2] provide structural details in solution and in the solid state. [source]

, -Cyclodextrin as Inhibitor of the Precipitation Reaction between Berberine and Glycyrrhizin in Decoctions of Natural Medicines: Interaction Studies of Cyclodextrins with Glycyrrhizin and Glycyrrhetic Acid by 1H-NMR Spectroscopy and Molecular-Dynamics Calculation

HELVETICA CHIMICA ACTA, Issue 9 2008
Miyoko Kamigauchi
Abstract To prevent the precipitation reaction between glycyrrhizin (1) and berberine (3) in the decoctions of Glycyrrhiza/Coptis rhizome or Glycyrrhiza/Phellodendron bark, the presence of cyclodextrin (CD) in the mixture was proven to be effective. The preventing effect decreased in the order , -CD>, -CD, and no effect was observed for , -CD. On the other hand, the extraction degree of 1 from the natural medicine Glycyrrhia was considerably increased in the presence of , -CD, , -CD being much more effective than , - or , -CD. Thus, the blocking effect of CD on the precipitate formation between 1 and 3 is suggested to be primarily dependent on the stability of the inclusion complex of the CD with 1. To establish the structure of such a preferred inclusion complex, the interactions of 1 with , - and , -CDs were investigated by 1H-NMR spectroscopy and molecular-dynamics (MD) calculations. The 1H-NMR measurements showed that the increase in solubility of 1 in H2O is dependent on the degree of its inclusion into the CD, which depends on the molecular size of the CD. The MD calculations suggested that the H-bond interactions are sufficiently strong to form a stable [1/, -CD] complex, in which the lipophilic rings C, D, and E of 1 are fully inserted into the molecular cavity of , -CD, thus forming a kind of structure covered by a hydrophilic molecular capsule, while such an interaction mode is impossible for , - or , -CD. [source]

Self-Assembled Molecular Reaction Vessels Reloaded

CHEMCATCHEM, Issue 10 2010
Prof.
Enzyme-like catalysis of Nazarov cyclizations has been achieved by encapsulation of pentadienols into a metallosupramolecular capsule. Constrictive binding of the substrate and functional-group activation give rise to a tremendous rate acceleration of up to a factor of 2.1×106, thus, pushing the efficiency of self-assembled molecular capsules as catalysts to a new level. [source]