Search results for "ether"
showing 10 items of 986 documents
Probing the low-temperature chemistry of ethanol via the addition of dimethyl ether
2018
Considering the importance of ethanol (EtOH) as an engine fuel and a key component of surrogate fuels, the further understanding of its auto-ignition and oxidation characteristics at engine-relevant conditions (high pressures and low temperatures) is still necessary. However, it remains difficult to measure ignition delay times for ethanol at temperatures below 850 K with currently available facilities including shock tube and rapid compression machine due to its low reactivity. Considering the success of our recent study of toluene oxidation under similar conditions [38], dimethyl ether (DME) has been selected as a radical initiator to explore the low-temperature reactivity of ethanol. In …
Micropollutants removal in an anaerobic membrane bioreactor and in an aerobic conventional treatment plant
2012
The paper expresses an attempt to tackle the problem due to the presence of micropollutants in wastewater which may be able to disrupt the endocrine system of some organisms. These kinds of compounds are ubiquitously present in municipal wastewater treatment plant (WWTP) effluents. The aim of this paper is to compare the fate of the alkylphenols-APs (4-(tert-octyl)) phenol, t-nonylphenol and 4-p-nonylphenol and the hormones (estrone, 17ß-estradiol and 17¿-ethinylestradiol) in a submerged anaerobic membrane bioreactor (SAMBR) pilot plant and in a conventional activated sludge wastewater treatment plant (CTP). The obtained results are also compared with the results obtained in a previous stud…
Genome-wide meta-analysis identifies six novel loci associated with habitual coffee consumption
2015
Contains fulltext : 155360.pdf (Publisher’s version ) (Closed access) Coffee, a major dietary source of caffeine, is among the most widely consumed beverages in the world and has received considerable attention regarding health risks and benefits. We conducted a genome-wide (GW) meta-analysis of predominately regular-type coffee consumption (cups per day) among up to 91,462 coffee consumers of European ancestry with top single-nucleotide polymorphisms (SNPs) followed-up in ~30 062 and 7964 coffee consumers of European and African-American ancestry, respectively. Studies from both stages were combined in a trans-ethnic meta-analysis. Confirmed loci were examined for putative functional and b…
Partialsynthese neuer Ergolinderivate aus Clavinalkaloiden, 3. Mitt.1) O-Acyl- und O-Alkyl-1,6-dimethyl-8-hydroxymethyl-ergol-9-ene
1983
Elymoclavin (1), Lysergol (2) und O-Acyl-lysergole werden in flussigem Ammoniak mit Kalium und Methyliodid zunachst am Indolstickstoff methyliert. Durch Variation der Versuchsbedingungen werden 1 und 2 sekundar auch an der Hydroxylgruppe methyliert. Aus 1-Methyl-lysergol (3) sind daher nach der gleichen Methode mit verschiedenen Alkyliodiden 1-Methyl-lysergol-ether darstellbar. Dagegen gelingt die Ethersynthese nach Williamson aus 17-Halogen-ergolenen nicht. Partial Synthesis of New Ergoline Dervatives from Clavine Alkaloids, III: O-Acyl-and O-Alkyl-1,6-dimethyl-8-(hydroxymethyl)ergol-9-enes Elymoclavine (1), lysergole (2) and O-acyllysergoles are primarily methylated at the indole nitrogen…
Über Zinn‐haltige Heterocyclen, IV 1) 5,5‐Diphenyl‐1,4,6,5‐oxadithiastannocan, Fixierung eines konformativen Übergangszustandes in der Kristallstrukt…
1981
Die Titelverbindung 1f wurde durch Reaktion von Ph2SnCl2 mit dem Dinatriumsalz des Bis(2-mercaptoethyl)ethers gewonnen. Die Kristallstruktur wurde bestimmt und bis R = 0.054 verfeinert. Die Konformation des 8-gliedrigen Heterocyclus liegt im Bereich des Sattelpunktes fur den Ubergang Sessel-Sessel = Wanne-Sessel Konformation. Die Konfiguration um das Sn-Atom liegt zwischen tetraedrischer 4- und trigonal-bipyramidaler 5-Koordination (transannularer Sn···O-Abstand 266.0 (7) pm). On Heterocyclic Systems Containing Tin, IV1) 5,5-Diphenyl-1,4,6,5-oxadithiastannocane, a Conformational Transition State Stabilized in a Crystal Structure The title compound 1f has been synthesized from Ph2SnCl2 and t…
Thiophen—Mangantricarbonyl-Komplexe
1967
Abstract Cationic thiophenemanganese tricabonyl complexes of the formula [C 4 (CH 3 ) x H 4- x S Mn(CO) 3 ] + have been prepared with 2-methyl-, 3-methyl-, 2,5-dimethyl-, 2,3,5-trimethyl-, tetramethylthiophene, and with thiophene by the reaction of Mn(CO) 5 Cl+AlCl 3 or AlBr 3 with the thiophenes in petrol ether, at 100–110°. The complexions give yellow solutions which are fairly stable. Their IR and some NMR spectra are given and discussed.
Untersuchungen zur Diastereoselektivität beim O ‐Angriff von Elektrophilen auf β‐Ketocarbonsäureester‐Enolate
1989
Aus den in reiner Form eingesetzten Z- oder E-Enolen 2a–c werden uber die Enolatstufe 3a–c die O-alkylierten, -silylierten oder -acylierten Produkte 4aa–ae, 4ba, bf und 4ca, cc, cf hergestellt. Im Gegensatz zu der vollstandigen Regioselektivitat hangt die Z/E-Diastereoselektivitat dabei von den Substituenten in 2/3, dem verwendeten Elektrophil und den Reaktionsbedingungen ab. Insbesondere bei weichen Elektrophilen kann sich das Z/E-Verhaltnis bei der Umsetzung 34 stark andern. On the Diastereoselectivity of the O-Attack of Electrophiles on Enolates from β-Ketocarboxylates The O-alkylated, -silylated or -acylated derivatives 4aa–ae, 4ba, bf, 4ca, cc, cf of the pure Z or E enoles 2a–c are gen…
A “Cation-less” Oxalate-Based Ferromagnet Formed by Neutral Bimetallic Layers: {[Co(H2O)2]3[Cr(ox)3]2(18-crown-6)2}∞ (ox = Oxalate Dianion; 18-crown…
2007
Neutral layers of the bimetallic oxalate complex {[Co(H2O)2]3[Cr(ox)3]2}∞ are formed in the presence of a crown ether and stabilized by hydrogen bonding. The resulting soluble ferromagnet orders at Tc = 7.4 K.
Über polygermane
1986
Summary Reaction of LiGePh2GePh3 with Cl2GePh2 at −65°C in ether yields n-Ge5Ph12 as the main product, in addition to shorter-chained polygermanes. The analysis of the resulting products and the isolation of the pentagermane was done by HPLC. The crystal structure was determined (R = 0.095). The conformation of the Ge5 chain is antiperiplanar-anticlinal (−179.3 and +114.4°) with mean Ge-Ge distances of 247.6 (central) and 244.3 pm (terminal).
Anchimer beschleunigte Homolysen, V. Thermische und Fluoridionen‐katalysierte Umlagerungen von Benzyl)‐[9‐(trimethylgermyl)‐9‐fluorenyl]‐ether
1980
Anchimerically Enhanced Homolyses, V. Fluoride Ion Catalysed Rearrangements of Benzyl 9-(Trimethylgermyl)-9-fluorenyl Ether The thermal rearrangement (homolysis) of the germanium compound 1d into 4d is considerably slower than that of the analogous Si compound 1c. Thus, a correlation is suggested between the velocity of the rearrangement and the strength of the new bond to oxygen. The rearrangement 1d4d is also induced by fluoride ions at room temperature.