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1.
The catalyst of rare earth(III) perfluorooctanesulfonates (RE(OSO2C8F17)3, RE = Sc, Y, La-Lu) were prepared from either rare earth chlorides(III) or oxides and perfluorooctanesulfonic acid. The perflates thus obtained act as novel catalysts for Friedel-Crafts alkylation in fluorous biphasic system. Perfluorohexane (C6F14), perfluoromethylcyclohexane (C7F14), perfluorotoluene (C7F8), perfluorooctane (C8F18), perfluorooctyl bromide (C8F17Br) and perfluorodecalin (C10F18, cis- and trans-mixture) can be used as fluorous solvents for this reaction. By simple separation of the fluorous phase containing only catalyst, alkylation can be repeated many times. 相似文献
2.
Detection of perfluorocarbons using ion mobility spectrometry 总被引:1,自引:0,他引:1
An ISAS custom-designed ion mobility spectrometer equipped with a ionization source is used for the sensitive detection of traces of perfluorocarbons (PFCs, C5F12 to C9F20) in air, a class of substances for which a growing interest for industrial and environmental applications arose within the last years. Mobility spectra of the PFCs are presented, compared and discussed with regard to the possibility of identifying these analytes; detection limits are determined to be in the upper ng l−1 range. Using a specific PFC as an example, a way to prevent unwanted contributions of non-product ions, the difference mobility spectrum, is introduced and described. Advantages and possibilities of this technique are briefly discussed. 相似文献
3.
Fluorous quaternary ammonium and phosphonium salts, as well as fluorous macrocyclic ligands, such as crown and aza-crown ethers, have been gradually emerging as viable alternatives to classical phase transfer catalysts. The major results thus far obtained in this burgeoning field will be the focus of this review. 相似文献
4.
Maria Carmelita Z. Kasuya Xiaonan Wen Kenichi Hatanaka Kageyasu Akashi 《Journal of fluorine chemistry》2011,132(11):978-981
Incubation of mouse melanoma B16 cells in fluorous solvents with low boiling point such as perfluoromethylcyclohexane, 1,1,1,3,3,3-hexafluoro-2-propanol, ethylpentafluoropropionate resulted in cell death. However, cells lived up to 2 days in fluorous alcohols such as 2,2,3,3,4,4,5,5-octafluoro-1-pentanol and 3,3,4,4,5,5,6,6,6-nonafluoro-1-hexanol with relatively higher fluorine content. Remarkably, cells survived deprived of nutrition up to 4 days when incubated in 2,2,3,3,4,4,5,5,6,6,6-undecafluoro-1-hexanol or in 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoroheptanol that have the most number of fluorine atoms (11 and 12, respectively) among the perfluoroalkyl alcohols used, and with boiling points of 128 °C and 169 °C, respectively. 相似文献
5.
Archan Dey Tullio Pilati Giuseppe Resnati Giancarlo Terraneo Ivan Wlassics 《Journal of fluorine chemistry》2009,130(9):816-4475
Perfluoroalkyl chains in solids are highly disordered in a wide range of temperatures. Poor attention is typically given to this problem in crystallographic studies to the point that no attempt is frequently made in order to model the collected data and disorder remains even unmentioned in a large number of single crystal reports. This paper presents a short analysis of the problems related with this disorder. Two simple crystal structures, namely the halogen bonded adducts between N,N,N′,N′-tetramethyl-1,4-phenylendiamine and α,ω-diiodoperfluorobutane or α,ω-diiodoperfluorohexane are discussed in details in order to suggest some simple and basic principles for the refinement of perfluoroalkyl chains in single crystal structural studies. 相似文献
6.
Giuseppe Gattuso Rosalba Liantonio Pierangelo Metrangolo Franck Meyer Andrea Pappalardo 《Supramolecular chemistry》2013,25(3):235-243
1,3-Bis(α-picolyloxy)-p-tert-butylcalix[4]crown-5 in the cone conformation (2), 1,8-diiodoperfluorooctane or 1,6-diiodoperfluorohexane, and potassium iodide ternary mixtures undergo in solution self-sorting and afford crystalline “supramolecular salts”. These hybrid materials consist of supercation [K+ ? 2] and superanion [I–(CF2) n –I…I? …I–(CF2) n –I…I? …] (n = 6,8) components. In the supercations the potassium ion is embedded in the ionophoric pocket created by the heteroatoms present at the lower rim. In the superanions the iodide ions form infinite fluorous polyanionic chains as a result of a self-assembly process which relies on halogen bonding. Both cation encapsulation and anion-perfluorocarbon halogen bonding were detected in solution by 1H and 19F NMR, and in the gas phase by ESI MS. 相似文献
7.
Julio Cárdenas-Rodríguez Christine M. Howison Terry O. Matsunaga Mark D. Pagel 《Magnetic resonance imaging》2013
Dynamic Contrast Enhancement (DCE) MRI has been used to measure the kinetic transport constant, Ktrans, which is used to assess tumor angiogenesis and the effects of anti-angiogenic therapies. Standard DCE MRI methods must measure the pharmacokinetics of a contrast agent in the blood stream, known as the Arterial Input Function (AIF), which is then used as a reference for the pharmacokinetics of the agent in tumor tissue. However, the AIF is difficult to measure in pre-clinical tumor models and in patients. Moreover the AIF is dependent on the Fahraeus effect that causes a highly variable hematocrit (Hct) in tumor microvasculature, leading to erroneous estimates of Ktrans. To overcome these problems, we have developed the Reference Agent Model (RAM) for DCE MRI analyses, which determines the relative Ktrans of two contrast agents that are simultaneously co-injected and detected in the same tissue during a single DCE-MRI session. The RAM obviates the need to monitor the AIF because one contrast agent effectively serves as an internal reference in the tumor tissue for the other agent, and it also eliminates the systematic errors in the estimated Ktrans caused by assuming an erroneous Hct. Simulations demonstrated that the RAM can accurately and precisely estimate the relative Ktrans (RKtrans) of two agents. To experimentally evaluate the utility of RAM for analyzing DCE MRI results, we optimized a previously reported multiecho 19F MRI method to detect two perfluorinated contrast agents that were co-injected during a single in vivo study and selectively detected in the same tumor location. The results demonstrated that RAM determined RKtrans with excellent accuracy and precision. 相似文献
8.
Fluorocarbons have been successfully applied as oxygen carriers replacing blood. In order to understand the nature of the interaction between fluorocarbons and hydrocarbons on the one hand and O2, N2 and CO2 on the other, STO-3G calculations have been performed on their complexes. The very slight energies of interaction that were obtained seem to substantiate the contention that O2, N2 and CO2 are physically dissolved in fluorocarbons. This energy of interaction is, however, distinctly larger for fluorocarbons than for hydrocarbons. Electrostatic potentials have been computed around several fluorocarbons. They make it possible to predict the geometries of the complexes that are formed. 相似文献
9.
Summary Both sulphur hexafluoride and a group of compounds among the perfluorinated cyclic hydrocarbons: perfluorodimethyl cyclobutane,
perfluoromethyl cyclopentane, perfluoromethyl cyclohexane and the 1,2- and 1,3-isomers of perfluordimethyl cyclohexane are
well known to be good gas tracers, in various applications. Unfortunately different methods have been used for the analysis
of SF6 and the perfluorocarbons. Therefore, in many cases, the analytical costs may have hindered the use of both SF6 and the perfluorocarbons in the same tracer experiments. The analytical method described in this paper enables the determination
of both types of gas tracer in one single run. The new method has already replaced two former methods and was used to run
the gas tracer analysis routinely, proving the reliability of the method. 相似文献
10.
Phase behaviour measurement of binary mixtures of perfluoro-1,3-dimethylcyclohexane with methane and propane, and ternary mixtures of perfluoro-1,3-dimethylcyclohexane with methane + n-hexane and methane + n-decane at 373.15 K and over a wide range of concentration are presented. Measurements are made at the liquid bubble point and retrograde dew point pressures of the mixtures. A constant composition expansion test was carried out on perfluoro-1, 3-dimethylcyclohexane + methane mixture at 373.15 K. 相似文献