6-cyclodextrin-water-inclusion

Fujiwara T, Yamazaki M, Tbmiza Y, Ibkuoka R, Tomita K-I, Matsuo T, Suga H, Saenger W (1983) The crystal structure of a new form of yS-cyclodextrin water inclusion compound and thermal properties of /teyclodextrin inclusion complexes. Nippon Kagaku Kaishi 2 181-187... 

ABSTRACT. Smooth and stable cyclodextrin membranes are successfully prepared from the oriented-cyclodextrin-polymers, by drying layers of the polymers. The polymers are obtained by the reaction of the crystal of 3-cyclodextrin-water inclusion complex with hexamethylene diisocyanate as cross-linking agent in anisole. The cyclodextrin membranes exhibit selective permeation of various materials in water. 

Cyclodextrins form inclusion complexes, and their solubility in water at 25°C differs considerably, with y-cyclodextrin being the best soluble (23.2 g/100 mL) followed by a-cyclodextrin (14.5 g/100 mL) and p-cyclodextrin (1.85 g/100 mL). ... 

Tamaki, T. and Kokubu, T., Acceleration of the photodimerization of water-soluble anthracenes included by fi- and y-cyclodextrins, J. Inclusion Phenom., 1984,2, 815—822. 

Related to this, Martin et al. (1782) investigated the ability of [Cu(S2CNC4HgO)2] to act as a scavenger of the superoxide anion, which takes place through a SOD-like process. Since the complex is only poorly soluble in water, an inclusion compound was formed with p-cyclodextrin the inclusion constant was determined spectrophotometrically, and suggested the formation of a stable 2 1 inclusion complex. 

Water plays a crucial role in the inclusion process. Although cyclodextrin does form inclusion complexes in such nonaqueous solvents as dimethyl sulfoxide, the binding is very weak compared with that in water 13 Recently, it has been shown that the thermodynamic stabilities of some inclusion complexes in aqueous solutions decrease markedly with the addition of dimethyl sulfoxide to the solutions 14,15>. Kinetic parameters determined for inclusion reactions also revealed that the rate-determining step of the reactions is the breakdown of the water structure around a substrate molecule and/or within the cyclodextrin cavity 16,17). 

The rate acceleration imposed by 0-cyclodextrin was explained in terms of a microsolvent effect 6> The inclusion of the substrate within the hydrophobic cavity of cyclodextrin simulates the changes in solvation which accompany the transfer of the substrate from water to an organic solvent. Uekama et al.109) have analyzed the substituent effect on the alkaline hydrolysis of 7-substituted coumarins (4) in the... 

The theory and development of a solvent-extraction scheme for polynuclear aromatic hydrocarbons (PAHs) is described. The use of y-cyclodextrin (CDx) as an aqueous phase modifier makes this scheme unique since it allows for the extraction of PAHs from ether to the aqueous phase. Generally, the extraction of PAHS into water is not feasible due to the low solubility of these compounds in aqueous media. Water-soluble cyclodextrins, which act as hosts in the formation of inclusion complexes, promote this type of extraction by partitioning PAHs into the aqueous phase through the formation of complexes. The stereoselective nature of CDx inclusion-complex formation enhances the separation of different sized PAH molecules present in a mixture. For example, perylene is extracted into the aqueous phase from an organic phase anthracene-perylene mixture in the presence of CDx modifier. Extraction results for a variety of PAHs are presented, and the potential of this method for separation of more complex mixtures is discussed. 

Monflier and co-workers recently described a new approach based on the use of chemically modified /3-cyclodextrins to peform efficiently the functionalization of water-insoluble olefins in a two-phase system. These compounds behave as inverse phase transfer catalysis, i.e., they transfer olefins into the aqueous phase via the formation of inclusion complexes.322... 

Selective inclusion of naphthalene derivatives by monolayers of amphiphilic cyclodextrins at the air/water interface [23]. 

Braun T, Buvari-Barcza A, Barcza L, Konkoly-Thege I, Fodor M, Migali B (1994) Mechanochemistry a novel approach to the synthesis of fullerene compounds. Water soluble Buckminster fullerene - gamma- cyclodextrin inclusion complexes via solid-solid reaction. Solid State Chem. 74 47-51. 

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