Cyclodextrins organic compounds

R SiH and CH2= CHR interact with both PtL and PtL 1. Complexing or chelating ligands such as phosphines and sulfur complexes are exceUent inhibitors, but often form such stable complexes that they act as poisons and prevent cute even at elevated temperatures. Unsaturated organic compounds are preferred, such as acetylenic alcohols, acetylene dicarboxylates, maleates, fumarates, eneynes, and azo compounds (178—189). An alternative concept has been the encapsulation of the platinum catalysts with either cyclodextrin or in thermoplastics or siUcones (190—192). 

Solid-surface room-temperature phosphorescence (RTF) is a relatively new technique which has been used for organic trace analysis in several fields. However, the fundamental interactions needed for RTF are only partly understood. To clarify some of the interactions required for strong RTF, organic compounds adsorbed on several surfaces are being studied. Fluorescence quantum yield values, phosphorescence quantum yield values, and phosphorescence lifetime values were obtained for model compounds adsorbed on sodiiun acetate-sodium chloride mixtures and on a-cyclodextrin-sodium chloride mixtures. With the data obtained, the triplet formation efficiency and some of the rate constants related to the luminescence processes were calculated. This information clarified several of the interactions responsible for RTF from organic compounds adsorbed on sodium acetate-sodium chloride and a-cyclodextrin-sodium chloride mixtures. Work with silica gel chromatoplates has involved studying the effects of moisture, gases, and various solvents on the fluorescence and phosphorescence intensities. The net result of the study has been to improve the experimental conditions for enhanced sensitivity and selectivity in solid-surface luminescence analysis. 

Solid-surface luminescence analysis involves the measurement of fluorescence and phosphorescence of organic compounds adsorbed on solid materials. Several solid matrices such as filter paper, silica with a polyacrylate binder, sodium acetate, and cyclodextrins have been used in trace organic analysis. Recent monographs have considered the details of solid-surface luminescence analysis (1,2). Solid-surface room-temperature fluorescence (RTF) has been used for several years in organic trace analysis. However, solid-surface room-temperature phosphorescence (RTF) is a relatively new technique, and the experimental conditions for RTF are more critical than for RTF. 

Investigating the bioavailability and biodegradation of various organic compounds in the presence of cyclodextrins for in situ environmental applications. 

Cyclodextrins are water-soluble materials and provide a hydrophobic microenvironment in water. On this basis, CDs can accommodate various organic compounds, and unique reactions may proceed in the constrained media. In this chapter, we have described mainly modified CDs with one, two, or more chro-... 

Ko, S.-O., Schlautman, M.A., and Carraway, E.R. (1999). Partitioning of hydrophobic organic compounds to hydroxypropyl--P-cyclodextrin Experimental studies and model predictions for surfactant-enhanced remediation applications. Environ. Sci. Technol., 33, 2765-2770. 

Fukushima, M. Osa, T. and Ueno, A. (1991) Photoswitchable Multi-response Sensor of Azobenzene-modified y-Cyclodextrin for Detecting Organic Compounds, Chem. Lett. 709-712. 

Potential use of complexes of y - CD with organic compounds, including polymers, was also reviewed by Szejtli [6, 12, 13], y - CD are able to incorporate metal ions as ligands to prepare magnetic nano - particles [7,14], Harada and Ka-machi [8,15] first found that poly (ethylene oxide) (PEO) thread a- CD rings to form polymer - cyclodextrin complex. Since their finding of inclusion complex formation of polymer chains with a- CD, a large number of studies on inclusion complexes of... 

Calixarenes and cyclodextrins (CDs) are the simplest combination of organic compounds able to form molecular cavities. The relative ease of functionalization makes them versatile enzymatic binding site mimics [24]. These cavitands can af-... 

Wang X, Brusseau ML. Simultaneous complexation of organic compounds and heavy metals by a modified cyclodextrin. Environ Sci Technol 1995 29 2632-2635. 

Brusseau ML, Wang X, Wang W-Z. Simultaneous elution of heavy metals and organic compounds from soil by cyclodextrin. Environ Sci Technol 1997 31 1087-1092. 

Takeo, K.,Kuge, T. 1969. Complexes of starchy materials with organic compounds. Part III. X-Ray studies on amylose and cyclodextrin complexes. Agric. Biol. Chem. (Tokyo), 33, 1174-1180. 

Calculate the area(s) under the peak for each volatile organic compound, and convert it to milligrams per kilograms of gamma-Cyclodextrin using the response factor for 8-cyclo-hexadecen-l-one. The response factor is determined from a calibration curve using 8-cyclohexadecen-l-one concentrations of 0.1 to 6 mg/100 mL of hexane. 

Of the new Pt catalysts reported since 1990 platinum complexes with new ligands and activators are noteworthy. Cyclodextrin complexes of platinum (as host-guest complexes) have been employed as hydrosilylation catalysts active at elevated temperature after releasing the guest compound [40]. Some other organic compounds have recently been used as activators (ligands) of Pt complexes, e. g., unsaturated secondary and tertiary alcohols and silylated unsaturated alcohols [41], alkadiynes, cyclooctadiene [42], and vinylnorbomene as well as quinones and methylnaphthoquinones [43]. 

Zheng, X. M. Lu, W. M. Sun, D. Z., Enthalpy and entropy criterion for the molecular recognize of some organic compounds with beta cyclodextrin, Acta. Phys-Chim. Sin. 2001, 17, 343-347... 

Cyclodextrins can also be used to make some organic compounds that are insoluble in water go into aqueous solution. These were discussed in Chap. 5. 

Cyclodextrins can be functionalized with various types of chromophores on both the primary and the secondary hydroxyl rims. A review of the prepared, selectively 0-substituted, CDs has been published [204], The modified CDs show interesting photochemical properties which have been exploited to detect photochemically inactive organic compounds in aqueous solutions [205], to induce stero- and regioselectivity in some photochemical reactions, and to mimic the energy transport from the antenna to the reaction center in the photosynthetic membrane (vide infra). 

In more recent work the same group immobilized j8-cyclodextrin (CD) on solid support [27]. Initially 1,6-hexamethylene diisocyanate (HMDI) was quantitatively introduced as a linker to conventional PEGylated Merrifield resin (PS-PEG). fi-CD was subsequently attached to the prepared PS-PEG-HMDI polymer by microwave irradiation at 70 °C for 30 min (Scheme 16.4a). The resulting jS-CD resins are insoluble in water and can be used to trap volatile organic compounds from water. 

Maturi K, Reddy KR (2006). Simultaneous removal of organic compounds and heavy metals from soils by electrokinetic remediation with a modified cyclodextrin. Chemosphere 63(6) 1022-1031. 

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