Inclusion complexes formation with

Inclusion complex formation with fluorescent NBD-guests corroborated internal hydrophobicity of /3-barrel hosts and potential for intratoroidal catalysis <2002CH18>. 

The n values used here are derived from di-n-butylether/water partition coefficients since the ether phase was thought to better simulate the environment of the cavity of cyclodextrins. Eq 38 indicates that the principal driving force for the inclusion complex formation with P-cyclodextrin is the dehydration from surroundings of the guest molecule. 

In Eq. 39, substituents, the dimension of which is larger than 5.1 A in terms of the sum of the opposite-pair Bj values, are not included, since their log (1/Kd) values are much lower than those expected from the correlation for others. They are supposed not to be accomodated into the cavity of the a-cyclodextrin, the diameter of which is 4.5-5 A. Thus, the inclusion complex formation with a-cyclodextrin is more limited than that with P-cyclodextrin and the extent of dehydration is less significant. The term B in Eq. 39 implies that the larger the minimum width of substituents the maximum diameter of which is less than 5.1 A, the more uniform would be the van der Waals interaction with the cavity wall resulting in the more stable inclusion complex. 

Fig. 20 Schematic illustration of a predominant one-handed helix induction in 60 by inclusion complex formation with a chiral guest molecule 61...

Fig. 4. Plot of the changes of the C-chemical shifts in ppm) of the guest compounds on inclusion complex formation with a-cyclodextiin vs. the penetration depth (Z in A) the positive sign in 4 c shows an increase in shielding, and a positive sign in Z shows deeper penetration with respect to the plane ( Z = 0) comprised of the 6 H-3 atoms of a-cyclodextrin the numbering systems of the carbon atoms of the guest compounds are as follows ...

The most important applications of chiral mobile phase additives in liquid ehromatogra-phy are ehiral ion-pair chromatography (section 4.3.3) and inclusion complex formation with cyclodextrins and similar chiral selectors. Other ehiral mobile phase additives have been used only oeeasionally, and with modest sueeess [ 1,3,32,153]. Multifunctional ion-pair reagents, such as 10-camphorsulfonic acid [154], derivatives of tartatie acid (e.g. di-n-butyltartrate) [155,156], peptides (e.g. N-carbobenzoxyglyeine-L-proline) [157-161],... 

Inclusion complex formation with CDs usually results in a higher fluorescence quantum yield or the lifetimes of the excited states. It has been found that the... 

Inclusion complex formation with cycloamylose has been shown to be a technically simple process by which the ratio of saturated to unsaturated fatty acids may be altered under mild conditions in fatty acid mixtures obtained from natural sources. Complex formation was demonstrated by the results of X-ray diffraction spectra, the low solubility of the formed complexes, and the protection of the complexed fatty acids against atmospheric oxidation. 

It seems important to notice that CDs can be used for separation of enantiomers of chiral compounds by CE not only in aqueous buffers but also in non-aqueous media. " Contrary to the assumption that inclusion complex formation with CDs may not be favored in non-aqueous buffers, our recent studies indicate that CDs may form inclusion complexes also in non-aqueous buffers. In addition, noninclusion type complexes of CDs are also enantioselec-tively formed with chiral analytes, which may lead to separation of enantiomers in CE. 

ABSTRACT. Novel optical resolutions of guest compounds by inclusion complex formation with optically active host compound are reviewed Tertiary acetylenic alcohols, cyanohydrins, and secondary alcohols were resolved by complexation with alkaloids such as brucine or sparteine. Cycloalkanones, 2,3 -epoxycyclohexanones, and some other neutral compounds were resolved by complex formation with optically active diacetylenic diol. Mutual optical resolution of bis-g-naphthol and sulfoxides by complex formation was also reviewed. 

Figure 7 Schematic representation of three-step targeting approach based on guest inclusion complex formation with cyclodextrin. (Adapted from Ref. 31. Springer, 2007.)...

Polarography measures the electron distribution of guest molecule. Specific rotation, which is an inherent property of the optically active species, is measured by polarimetry, as it may be affected by complex formation. Solution conductivities are vividly affected by inclusion complex formation with cyclodextrins. 

J. Manosroi, M.G. Apriyani, K. Foe, and A. Manosroi, Enhancement of the release of Azelaic acid through the synthetic membranes by inclusion complex formation with hydroxypropyl-(3-cyclodextrin, Int. / Pharm., 293,235-240,2005. 

Kida T, Minabe T, Okabe S, Akashi M (2007) Partially-methylated amyloses as effective hosts for inclusion complex formation with polymeric guests. Chem Commun 1559-1561 Kitaoka M, Hayashi K (2002) Carbohydrate-processing phosphorolytic enzymes. Trends Glycosci Glycotechnol 14 35-50... 

As shown in Figure 3, the penetration rate of CN decreased with the addition of 3 CD (No. 3). This may be due to a decrease in the concentration of free drug by the inclusion complex formation with 3-CD. When DL-phenylalanine was added, the penetration rate constant was restored (No. 5). This means an increase in free drug concentration by the competing action of DL-phenylalanine. DL-phenylalanine did not affect the penetration rate of CN in the case without 3-CD (No. 2). 

Fig. 38.16 Flexibility of the /)ora-sulph(Hiatocalix[5]arene host (a) host ctmfonnation (top) and 1 1 inclusion complex formation with 1,10-phenantrolinium cation [34] (b) host conformatiMi (top) and 2 2 inclusion complex formation with 1,10-phenantrolinium cation [34] (c) host conformation (top) and 2 2 inclusion complex framation with l,4-diazabicyclo(2.2.2)octanium cation [35] (d) host conformation (top) and 1 1 inclusion complex formation with ethane-1,2-bis (4,4 -bipyridinium) cation [36]...

There is only eight crystal structures of calix[7]arenes deposited in CSD. The reason for this is much more difficult synthesis of seven-membered calixarenes and/or difficulties in obtaining monocrystals of this compounds and their complexes/co-crystals. Like for smaller calixarenes discussed above also here the self-inclusion of one of the substituent may occur like in para-t-hvXy -carboxymethoxycalix[7]arene/deuterochloroform clathrate (Fig. 38.25a) [52] or inclusion complexes are obtained. For the later, due to a great degree of flexibility, many conformations of calixarene host molecule is possible but the most observed is a double partial cone, e.g. 1 2 para-t-butyl-calix[7]arene/pyridine inclusion complex where one guest molecule is located in each partial cone cavity (Fig. 38.25b) [53]. In one case the flattened cone conformation was found where the (Fig. 38.25c). In this crystal structure one toluene and one disordered benzene/ toluene molecule are involved in inclusion complex formation with one para-t-butyl-calix[7]arene molecule [54]. 

Commonly, inclusion complex formation with CB7 can be applied to enhance the fluorescence response of guest (Megyesi et al., 2008), for example berberine, a clinically important natural alkaloid. When using CB7 as macrocyclic host compound, a very stable 1 1 inclusion complex formed and led to about 500-fold fluorescence intensity enhancement, which can facilitate the detection of berberine even below nanomolar concentration. The change of association constant and the fluorescence quantum yield of the complex can be accomplished by the addition of NaCl. Interestingly, l-alkyl-3-methylimidazolium typ>e ILs can modify the fluorescent properties of the complex much more efficiently than NaCl. It is the result that the formation of ternary complex by time-resolved fluorescence studies. The results can be applied in enzyme assays, because berberine fluorescence is insensitive to the environment, such as pH and the other compounds. On the other hand, inclusion complex formation can be used to separation processes. Because [CnmimJBr is only capable of... 

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