calixarenes has been researched along with tetrahydrofuran* in 2 studies
2 other study(ies) available for calixarenes and tetrahydrofuran
| Article | Year |
|---|---|
Structure of a piperidine-modified calix[4]arene derivative and spectral resolution of its interaction with rare earth metals with chemometric methods.
A piperidine-modified calix[4]arene derivative was synthesized and its structure was confirmed with X-ray diffraction data. UV-visible spectroscopy was used to study its molecular recognition of rare earth ions. The results revealed the calix[4]arene derivative could separate tight metal picrate ion pairs by complexation with the rare earth metal ions in tetrahydrofuran. Resolution of the UV-visible spectra with chemometric methods revealed that the derivative and the rare earth ions Eu(3+), Dy(3+), and Tb(3+) formed ML(2) complexes with stability constants of 10(8.26), 10(8.29), and 10(7.41) respectively. Topics: Calixarenes; Coordination Complexes; Crystallography, X-Ray; Furans; Metals, Rare Earth; Models, Molecular; Phenols; Piperidines; Spectrophotometry, Ultraviolet | 2013 |
Redox dependence of the reaction of alpha-alkoxyalkyl radicals with a series of oxidants.
Oxygen and oxidants enhance the sensitivity of cells to radiation. To understand this effect at the mechanistic level, the redox dependences for the reactivity of weakly reducing alpha-monoalkoxyalkyl radicals of 1,4-dioxane and tetrahydrofuran with a series of oxidants, for example, quinones, viologens, and nitro-arenes, with one-electron reduction potentials E71 values ranging from -80 to -640 mV, have been determined using the technique of pulse radiolysis. The second-order rate constants for these reactions with the alpha-monoalkoxyalkyl radicals of 1,4-dioxane and tetrahydrofuran are in the range (0.03-1.5) x 109 and (1.0-6.6) x 109 dm3 mol(-1) s(-1), respectively. The reactions of the alpha-alkoxyalkyl radicals of 1,4-dioxane with quinones and viologens involve an outer-sphere electron transfer, in contrast to a reaction with the nitro-arenes to give adducts. The resulting long-lived nitroaromatic adduct radicals were found to react with the reductant, TMPD, probably leading to the formation of hydroxylamine-type products. In cells, adducts formed on reaction of deoxyribose sugar radical with oxidants and subsequent reactions with reductants may contribute to the mechanisms involved in radiosensitization by oxygen and those oxidants that interact through adduct formation. Topics: Calixarenes; Dioxanes; Free Radicals; Furans; Oxidants; Oxidation-Reduction; Quinones; Viologens | 2009 |