Perfluorobutane

HBCD hexabromocyclododecane, HCB hexachlorobenzene, p,p -DDT Dieldrin, 1,1,1-trichloro-2,2-bis-(4-chlorophenyl)-ethane, p,p -DDE l,10-dichloro-2,20-bis(4-chlorophenyl) ethylene, p,p -DDD l,10-dichloro-2,20-bis-(4-chlorophenyl)ethane, PFOS perfluorooctane sulfonate, PFHS perfluorohexane sulfonate, PFBS perfluorobutane sulfonate... 

The commercially available perfluorocarbon-based contrast agents for diagnosis for liver and heart echography include sonovue, a suspension of microparticles of galactose with surface microbubbles of air or sulfur hexafluoride (SFe) optizon, a suspension of perfluoropropane encapsulated in microspheres of albumin and sona-zoide, based on perfluorobutane (Phase 111). Other formulations of perfluorobutane... 

All the fluoroethanes are produced, but no butane is found, although fluorobutanes, ranging from butyl fluoride to perfluorobutane, have been identified. 

Newsted, J.L., Beach, S.A., Gallagher, S.P. and Giesy, J.P. (2008) Acute and chronic effects of perfluorobutane sulfonate (PFBS) on the mallard and northern bobwhite quail. Arch Environ Contam Toxicol, 54, 535—545. 

For molecular dynamics (MD) simulations to accurately reflect chain motions and conformational changes at various temperatures, the rotational barriers must be correct whether they arise from an explicit dihedral term, vdW interactions, or both. Barriers that are too low will allow disorder to occur at simulated temperatures far below experimental temperatures at which transitions and disorders in PTFE are observed. The validity of the barrier heights, especially the one at trans, obtained from the MOPAC AMI calculations and derived force field parameters above was called into question upon comparison to high level ab initio calculations on perfluorobutane (PFB), perfluoropentane (PFP), and... 

Perfluorobutane-2,3-dione reacts with sulfur tetrafluoride at room temperature to give a 1 2 adduct, perfiuorobutane-2,3-diol orthosulfitc (11), quantitatively.90... 

The product from the fluorination of thiophene over potassium tetrafluorocobaltate(III) varied, not surprisingly, with temperature.108 At 120 C, virtually the sole product was the dihydrothiophene 5, albeit in low yield (14%) this compound is obviously analogous to 2,2.5,5-tetra-fluoro-2,5-dihydrofuran from tetrahydrofuran and potassium tetrafluorocobaltate(IIl). At 350-370 °C, 5 is still a major product, but now seven others are also present, the main ones being 6-8 and the sulfur extruded product perfluorobutane. 

Conformational characteristics of PTFE chains are studied in detail, based upon ab initio electronic structure calculations on perfluorobutane, perfluoropentane, and perfluorohexane. The found conformational characteristics are fully represented by a six-state RIS model. This six-state model, with no adjustment of the geometric or energy parameters as determined from the ab initio calculations, predicts the unperturbed chain dimensions, and the fraction of gauche bonds as a function of temperature, in good agreement with available experimental values. 

Dihydroxylation of perfluorobut-2-yne by chromium(VI) oxide in oleum gives the corresponding perfluorobutane-2,3-dione (19) in low yield.89... 

Symmetrically 2,3-disubstituted perfluorooxiranes, such as perfluoro(2,3-dimethyloxirane) and perfluoro(2,3-diethyloxirane), have been converted into the expected ketones (perfluorobutan-2-one and perfluorohexan-3-onc, respectively) in high yields with antimony(V) fluoride, although temperatures over 150 C are required.43... 

The group CF2CHF2 is often completely stable towards alkali metal hydroxides as can be seen in 2,2,3,3-tetrafluoropropanoic acid (CHF2CF2C02H)17,20 or 17/,477-perfluorobutane (CHF2CF2CF2CHF2).17 However, there are exceptions such as the reaction of 2,2,3,3-tetra-fluoropropan-1-ol(CHF2CF2CH2OH)18 with methyllithium. In aryl-substituted aliphatic compounds. elimination of hydrogen fluoride from the side chain is facilitated when a conjugated double bond is formed,21,201 e.g. formation of 3.201... 

As another alternative to triflates, aryl nonaflates (ONf) are easily prepared from phenol and commerically available perfluorobutane sulfonyl fluoride 243, and used for Pd-catalysed coupling with halides [111]. Aryl nonaflates are more reactive than aryl triflates. / -Iodophcnyl nonaflate (244) gives 245 by chemoselective reaction of the... 

Recently, a process involving chemical recycling of PTFE using fluidized bed has been developed and patented.3 5 The optimum temperature is in the range of 545 to 600°C (1013 to 1112°F) and the main decomposition products are tetrafluoro-ethylene (TEE), hexafluoropropene (HFP), and cyclo-perfluorobutane (c-C4F8). The most important advantages of this process are that the monomers produced can be purified before repolymerization, which allows production of a more valuable product, and that the process is continuous.1... 

FSAs) N-ethyl perfluorobutane NEtFBSE F(CF2)4S02N(CH2CH3)... 

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