5069results about "Halogenated hydrocarbon preparation" patented technology

This invention is directed to making chemical derivatives of carbon nanotubes and to uses for the derivatized nanotubes, including making arrays as a basis for synthesis of carbon fibers. In one embodiment, this invention also provides a method for preparing single wall carbon nanotubes having substituents attached to the side wall of the nanotube by reacting single wall carbon nanotubes with fluorine gas and recovering fluorine derivatized carbon nanotubes, then reacting fluorine derivatized carbon nanotubes with a nucleophile. Some of the fluorine substituents are replaced by nucleophilic substitution. If desired, the remaining fluorine can be completely or partially eliminated to produce single wall carbon nanotubes having substituents attached to the side wall of the nanotube. The substituents will, of course, be dependent on the nucleophile, and preferred nucleophiles include alkyl lithium species such as methyl lithium. Alternatively, fluorine may be fully or partially removed from fluorine derivatized carbon nanotubes by reacting the fluorine derivatized carbon nanotubes with various amounts of hydrazine, substituted hydrazine or alkyl amine. The present invention also provides seed materials for growth of single wall carbon nanotubes comprising a plurality of single wall carbon nanotubes or short tubular molecules having a catalyst precursor moiety covalently bound or physisorbed on the outer surface of the sidewall to provide the optimum metal cluster size under conditions that result in migration of the metal moiety to the tube end.

A mutant hydrolase optionally fused to a protein of interest is provided. The mutant hydrolase is capable of forming a bond with a substrate for the corresponding nonmutant (wild-type) hydrolase which is more stable than the bond formed between the wild-type hydrolase and the substrate and has at least two amino acid substitutions relative to the wild-type hydrolase. Substrates for hydrolases comprising one or more functional groups are also provided, as well as methods of using the mutant hydrolase and the substrates of the invention. Also provided is a fusion protein capable of forming a stable bond with a substrate and cells which express the fusion protein.

A process for converting gaseous alkanes to liquid hydrocarbons wherein a gaseous feed containing alkanes is reacted with a dry bromine vapor to form alkyl bromides and hydrobromic acid vapor. The mixture of alkyl bromides and hydrobromic acid are then reacted over a synthetic crystalline alumino-silicate catalyst, such as a ZSM-5 zeolite, at a temperature of from about 150° C. to about 450° C. so as to form higher molecular weight hydrocarbons and hydrobromic acid vapor. Propane and butane which comprise a portion of the products may be recovered or recycled back through the process to form additional C5+ hydrocarbons. Various methods are disclosed to remove the hydrobromic acid vapor from the higher molecular weight hydrocarbons and to generate bromine from the hydrobromic acid for use in the process.

There are provided a liquid crystalline compound having a large negative Deltaepsilon, low viscosity, a large K33 / K11 value, a small Deltaepsilon / epsilonL and mutually excellent solubility even at extremely low temperature; a liquid crystal composition prepared from a liquid crystalline compound; and a liquid crystal display device fabricated from such a liquid crystal composition. The liquid crystalline compound of the present invention is a liquid crystalline compound represented by the following general formula (1): where, R<1 >represents hydrogen, fluorine, an alkyl group having 1 to 15 carbon atoms, or an alkenyl group having 2 to 15 carbon atoms; each of rings A<1>, A<2>, and A<3 >independently represents trans-1,4-cyclohexylene group, 1,4-cyclohexenylene group, trans-1,4-silacyclohexylene group, 1,4-phenylenegroup, 2,3-difluoro-1,4-phenylene group, 2-fluoro-1,4-phenylene group, 3-fluoro-1,4-phenylene group, pyrimidine-2,5-diyl group, pyridine-2,5-diyl group, 1,3-dioxane-2,5-diyl group, tetrahydropyrane-2,5-diyl group, 1,3-dithiane-2,5-diyl group, or tetrahydrothiopyrane-2,5-diyl group; X<1 >represents hydrogen or fluorine; Y<1 >represents hydrogen or an alkyl group having 1 to 15 carbon atoms; 1 represents an integer from 1 to 10; and each of m and n independently represents 0 or 1.

The present invention relates to compositions comprising at least one fluoroolefin and an effective amount of stabilizer that may be an epoxide, fluorinated epoxide or oxetane, or a mixture thereof with other stabilizers. The stabilized compositions may be useful in cooling apparatus, such as refrigeration, air-conditioning, chillers, and heat pumps, as well as in applications as foam blowing agents, solvents, aerosol propellants, fire extinguishants, and sterilants.

The present invention relates to a method for preparation of organofluoro compounds containing radioactive isotope fluorine-18. More particularly, the present invention relates to a method for preparation of organofluoro compound [18F]florbetaben or [18F]AV-45 having <Chemistry Formula 11> and <Chemistry Formula 12>, respectively, by reacting fluorine salt containing radioactive isotope fluorine-18 with alkyl halide or alkyl sulfonate in the presence of alcohol of Chemistry Formula 1 as a solvent to obtain high yield of organofluoro compound. Synthesis reaction according to the present invention may be carried out under mild condition to give high yield of the organofluoro compounds and the reaction time is decreased, and thereby is suitable for the mass production of the organofluoro compounds.