Inclusion complexes tris

The inclusion modes of flurbiprofen with beta cyclodextrin and with heptakis(2,3,6-tri-0-methyl)-beta cyclodextrin have been studied by Imai and coworkers. They showed that, although the Cotton effects in the circular dichroic spectra induced by beta cyclodextrin in / (-) and 5(+) flurbiprofen are identical, those induced by heptakis(2,3,6-tri-0-methyl)-beta cyclodextrin differ from each other and from those induced by beta cyclodextrin. C.p.-m.a.s. C-n.m.r. experiments showed that the cyclodextrin ring is probably more distorted in the flurbiprofen inclusion complex with methylated beta cyclodextrin than in that with beta cyclodextrin. 

Sec Schlcnk, Liebigs Ann. Chem. 1973, 1145, 1156. 1179, 1195. Inclusion complexes of tri-o-lhymotidc can be used in a similar manner see Arad-Yellin Green Knossow Tsoucaris J. Am. Chem. Soc. 19 3, 105. 4561. 

Gerdil et al. reported two examples involving the solid-gas reactions of inclusion complexes of tri-o-thymonide with alkene or epoxycyclopentanone. The complex 5 crystallized in /T3 2, and the reaction with singlet oxygen gave endoperoxide 6 however, the [other hand, the reaction of chiral crystals of the complex 7 with hydrogen chloride gave two products 8 and 9, ees of which were 9% and 22%, respectively. [13]... 

Another class of inclusion complexes containing phosphorus in the host structure are cyclophosphazenes. Sozzani and co-workers have reported 31P CP/MAS studies of two organic derivatives tris(o-phenylene-dioxy)cyclotriphosphazene (TPP) and tris(2,3-naphtalene-dioxy)cyclotri-phosphazene (TNP). In the cited works, SS NMR technique was employed to recognise guest-free TNP matrix and of ICs with guests, for example benzene, tetrahydrofuran and p-xylene. The 31P NMR spectra were particularly informative regarding the symmetry of the phos-phazene ring. 

Table 3. Inclusion Complexes with Tris-ortho-thymotide...

Abstract New applications of ID and 2D solid state (SS) NMR spectroscopy in structural studies of inclusion complexes (ICs) formed by organic host lattices (cyclodextrins, calixarenes, cyclophosphazenes, and fullerenes) are described. Each section of the review gives short characteristics of host molecules and recent applications of SS NMR. Less common systems, which are interesting as models for SS NMR studies, (bis[6-0,6-0 -(l,2 3,4-diiso-propylidene-a-D-galactopyranosyl) thiophosphoryl] disulfide (DGTD) and 1,2-dichloro-ethane/tris(5-acetyl-3-thienyl) methane (TATM)), are also discussed. 

There are of course more organic compounds which can be used as host molecules in the formation of inclusion complexes. For most of them, e.g. urea and thiourea, crown ethers, cholic acid, hydroquinone, tri-o-thymotides and Di-anin s compound, the literature describing SS NMR applications in structural... 

Tri-o-thymotide(114), a trioxa derivative of tribenzocyclododecane, has been one of the most quoted representatives of optically labile compounds. Since a number of reviews (19, 111) have extensively described the fascinating aspects of this compound, including its spontaneous optical resolution and inclusion complexing, we shall here focus attention on more recent work in this and related fields. 

The original assignment of M helicity to (+)-tri-o-thymotide based on CD spectral analysis (113) was corrected by an X-ray crystallographic study (114), which provided evidence that the (-)-enantiomer has the C3 symmetry of athree-bladed propeller with M helicity. Facile deformation from C3 symmetry in the crystal lattice has been suggested to explain this molecule s striking ability to form a vast number of inclusion complexes with a variety of molecular species (115). 

A variety of spectroscopies have been employed in a study of the electron transfer photophysics of 5-(l-carboxypyrenyl)- and 5-(l-pyrenyl)-2 -deoxyuridine. The inclusion complexes of a-, P- and y-CDs and 2,6-di-O-methyl and 2,3.6-tri-O-methyl P-CD have been investigated using UV (as well as NMR) spectroscopy. The electrochemical oxidation of 4-0-glucopyranosyl-D-glucose in the presence of bromide ions has been examined using cyclic chronovoltammetry. Un-derivatized oligosaccharides and other carbohydrate types were analysed by semimicrocolumn LC/pulsed amperometric detection. ... 

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