Search results for "METHANE"
showing 10 items of 1763 documents
ChemInform Abstract: Iodine Oxidative Coupling of Diene- and Triene-Diolates of Unsaturated Carboxylic Acids.
2010
Abstract Oxidative Coupling of the dianions of unsaturated carboxylic acids 1 , and 4 with iodine, which provides a convenient and facile preparation of γ,γ and e,e-dicarboxylic acids 2 and 5, apparently occurs through SET substitution of intermediate iodo-carboxylates.
Biogenic volatile organoiodine and organobromine hydrocarbons in the Atlantic Ocean from 42°N to 72°S
1997
During the cruise ANT X/1 and 2 of the research vessel Polarstern from November 1991 to March 1992, 39 surface water samples of the Atlantic Ocean from 42°N to 72.5°S were collected and analysed for their concentration of volatile iodinated and brominated hydrocarbons. The concentration of chlorophyll-a was used as an indicator for phytoplankton, which is one of the main producers of iodinated and brominated compounds in the ocean. For determination of chlorophyll-a, fluorescence spectroscopy was applied, whereas the measurement of halogenated volatile hydrocarbons was carried out by a purge and trap system with subsequent gas chromatographic separation and detection by an electron capture …
Über makrozwitterionen, 10. Versuche zur darstellung von makrozwitterionen aus α,ω-bifunktionellem poly(α-methylstyrol)
1975
Verschiedene Moglichkeiten zur Darstellung von Makrozwitterionen ohne polare Gruppen in der Polymerkette werden diskutiert. Unter Verwendung von 3-Dimethylaminopropyllithium als Initiator und Propansulton (2) als Kettenabbruchreagenz wurden α,ω-bifunktionelle Poly(α-methylstyrol)e 4 mit einer tert. Amino- und einer Lithiumsulfonat-Endgruppe (Molekulargewichtsbereich ≈ 103; Bifunktionalitat >90%) dargestellt. Die beiden Endgruppen wurden wie bei den entsprechenden monofunktionellen Polymeren analytisch (N,S) und spektroskopisch (IR und NMR) nachgewiesen. Obwohl die beiden Endgruppen der bifunktionellen Polymeren jeweils unabhangig in die freie Sulfonsaure-Gruppe bzw. in die Trimethylammonium…
Regioselektive Zinn(II)chlorid-induzierte N-Aralkoxy-alkylierung am 2,3-Dimethylindol
1986
2,3-Dimethylindole (1) reacts by tin(II)chloride catalysis with arylaldehydes in dichloromethane, which contains 0.2% ethanol, regioselectively to the indol-1-yl-aryl-ethoxy-methanes3 a, 3 b.
ChemInform Abstract: Homogeneous Metal-Based Catalysis in Supercritical Carbon Dioxide as Reaction Medium
2016
Above 31.1 °C and 73.8 bar, carbon dioxide reaches the supercritical state, being transformed into a fluid (scCO2) that has attracted interest in the last few decades as reaction medium for several transition-metal-catalyzed organic transformations. The main feature of this fluid rests on its capability to dissolve large amounts of other gases such as hydrogen, carbon monoxide, ethylene, or even methane and light alkanes. In this manner, very high concentrations of these reactants are available for catalysis. In this contribution a review of the main achievements of the use of transition-metal complexes as catalysts in scCO2 is presented.
Refractive Indices and Deviations in Refractive Indices of Trifluoromethanesulfonate-Based Ionic Liquids in Water
2011
Refractive indices were determined for four different ionic liquid + water binary systems, from (288.15 to 338.15) K, and covering the entire composition range. The four ionic liquids used were 1-ethyl-3-methylimidazolium trifluoromethanesulfonate, 3-butyl-1-ethylimidazolium trifluoromethanesulfonate, 3-butyl-1-methylimidazolium trifluoromethanesulfonate, and 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate, all of them being completely miscible in water. From the experimental data, deviations in refractive indices, defined on a volume fraction basis, have been calculated and fitted to an extended version of the Redlich–Kister equation. The behavior of the deviations in refractive in…
Über die Darstellung und Polymerisation von 4-Vinyldiphenyl, 11-Vinyl-p-terphenyl und 1 2-Vinyl-p-terphenyl
1969
Fur die Darstellung von 4-Vinyldiphenyl und 11-Vinyl-p-terphenyl wurden einfache, verallgemeinerungsfahige Synthesen ausgearbeitet. Durch Umsetzung entsprechender Carbinole mit Methansulfonsaurechlorid in Pyridin gelang die Darstellung der Vinylverbindungen in einer einstufigen Reaktion. Die Untersuchung der radikalischen Copolymerization der Monomeren mit Styrol ergab bei 4-Vinyldiphenyl und 12-Vinyl-p-terphenyl einen bevorzugten Einbau in die Polymerketten, wahrend 11-Vinyl-p-terphenyl nur in untergeordnetem Mase in Polystyrolketten eingebaut wurde. The synthesis of 4-vinylbiphenyl and 11-vinyl-p-terphenyl was performed by a simple synthetic route. By reaction of the corresponding alcohol…
ChemInform Abstract: Highly Enantioselective Aza-Henry Reaction with Isatin N-Boc Ketimines.
2014
The asymmetric aza-Henry reaction of isatin N-Boc-ketimines (I) with nitromethane in the presence of a Cu-Ph-box complex leads to a series of N-Boc-protected nitroamines (III) with high enantioselectivity in most cases.
Shedding light on biogas: a transparent reactor triggers the development of a biofilm dominated by Rhodopseudomonas faecalis that holds potential for…
2019
AbstractConventional anaerobic digesters intended for the production of biogas usually operate in complete darkness. Therefore, little is known about the effect of light on microbial communities operating in anaerobic digesters. In the present work, we have studied through 16S rRNA gene amplicon Nanopore sequencing and shotgun metagenomic sequencing the taxonomic and functional structure of the microbial community forming a biofilm on the inner wall of a lab-scale transparent anaerobic biodigester illuminated with natural sunlight. The biofilm was composed of microorganisms involved in the four metabolic processes needed for biogas production. The biofilm proved surprisingly rich in Rhodops…
ChemInform Abstract: Preparation of N,O-Aminals as Synthetic Equivalents of H2C=NAr and (H2C=NHAr)+ Ions: Neutral- and Acid-Promoted Transformations.
1988
A general method for the synthesis of N,O-aminals derived from primary aromatic amines is described. The reactivity of these compounds under neutral and acidic conditions has been studied and the title compounds can be envisaged as general purpose H2CNAr or (H2CNHAr)+ equivalents. N,O-Aminals have been converted into perhydrotriazines by moderate heating and into bis(4-aminoaryl)methane derivatives or N-benzylarylamines, respectively when heated in acidic media with pH control. Reduction of N,O-acetals with sodium cyanoborohydride has revealed that the C–O bond is broken exclusively in acidic media.