Search results for "Onium"

PHOSPHORORGANISCHE VERBINDUNGEN 105.1Synthese chiraler und achiraler ditertiärer 1-Phosphino-2-Aminoethan-Derivate ([dbnd]P [sbnd]CH2[sbnd]CHR[sbnd]N…

1983

Abstract Primary amines with an optical active ligand add to vinyl- and propenylphosphonium salts according the reaction schemes (5) and (6), forming compounds of the type E and F. F contains a new asymmetric center in the bridge giving rise to the formation of a mixture of diastereomers, which can be resolved. Phosphonium salts of type E and F with a benzyl group on the phosphonium center are cleaved reductively by alkali amalgams (Li/Hg; Na/Hg; K/Hg) forming tertiary phosphines with an aminogroup in the β-position. The reductive cleavage with alkali amalgams is superior to the cathodic cleavage. Application: The synthesis of Ni(O)- and Pd(O)-complexes of type J fails. Bis-phosphine comple…

Über Inhibitoren der Korrosion III. Nachweis und Eigenschaften einiger mit Inhibitoren in Salzsäure aufgebauter Schutzschichten auf Eisen

1964

Fur den Aufbau einer Schutzschicht durch den Inhibitor oder eines seiner Folgeprodukte sprechen folgende Befunde: 1 Erhaltung der Schutzwerte nach Ubertragung inhibierter Drahte in inhibitorfreie, frische Salzsaure. 2 Verfolgung des zeitlichen Aufbaus der Schutzschicht durch den gleichen Test. 3 Erhaltung oder Verringerung der Schutzwirkung der inhibierten Drahte (a) durch Behandlung mit verschiedenen Losungsmitteln und (b) durch Bestimmung der thermischen Stabilitat der Schutzschicht. 4 Der an Blei- bzw. Quecksilberkathoden beobachtete Abbau quaternarer Phosphonium- und Arsoniumsalze eroffnet moglicherweise einen Zugang zu den am Aufbau der Schutzschichten beteiligten Verbindungen. On corr…

ChemInform Abstract: Rearrangements of Nitrile-Stabilized Ammonium Ylides

2014

Rearrangements of nitrile-stabilized ammonium ylides are useful reactions for the construction of alkylamines, nitrogen heterocycles, or carbonyl compounds. In spite of their attractive synthetic potential, they are much less frequently used than rearrangements of ammonium ylides either carrying charge-stabilizing carbonyl groups or being devoid of additional stabilization of the negative charge. This review focuses on different classes of rearrangements of nitrile-stabilized ammonium ylides as well as their application in synthetic organic chemistry. 1 Introduction 2 [1,2]-Stevens Rearrangements 3 [2,3]-Sommelet–Hauser Rearrangement 4 [2,3]-Stevens Rearrangements 5 Competitive [1,2]-, [2,3…

Ceric Ammonium Nitrate - a versatile oxidizing reagent

1994

ChemInform Abstract: Ceric Ammonium Nitrate - A Versatile Oxidizing Reagent

2010

ChemInform Abstract: On the Reactivity of Nitrosoimidazoles with Acids (the Cusmano-Ruccia Reaction): A Continuous Source of New Ring-into-Ring Inter…

2014

Abstract An extension of the ‘Cusmano–Ruccia’ reaction is reported. 6-(4-chlorophenyl)-3-methyl-5-nitrosoimidazo[2,1- b ]oxazole by the action of hydrochloric acid gives 3-(4-chlorobenzoyl)-5-methyl-1,2,4-oxadiazole ( 13 ); presumably via ammonium ion, CO 2 and methanol elimination. The relevance of the nature of the atom of the B -ring linked to C-2 of the imidazole for the occurrence of the ring-into-ring interconversion has been once more confirmed.

Eine neue synthese for 3-desoxy-3-iod-zucker über alkoxyphosphoniumsalze

1979

Abstract The alkoxy phosphonium iodides of the 1,2:5,6-di-O-isopropylidene-gluco- and allofuranose are converted to the corresponding 3-iodo sugars without elimination or rearrangement.

catena-Poly[benzyltriethylammonium [tri-μ-thiocyanato-κ4N:S;κ2S:N-cadmate(II)]]

2006

The title compound, {[(C6H5CH2)N(C2H5)3][Cd(SCN)3]}n, contains benzyl­triethyl­ammonium cations lying between one-dimensional chains of stoichiometry {[Cd(SCN)3]−}n. Each Cd2+ ion is 3N,3S-hexa­coordinated by thio­cyanate ligands in an octa­hedral arrangement. The asymmetric unit contains one cation and one anion.

Variability in inorganic and organic nitrogen uptake associated with riverine nutrient input in the Gulf of Riga, Baltic Sea

2001

Concentrations and rates of uptake of dissolved organic nitrogen (DON, free amino acids, and urea) and inorganic nitrogen (DIN, nitrate, and ammonium) were measured along two transects in the Gulf of Riga, a sub-basin of the Baltic Sea, during May and July 1996. Concentrations of total dissolved nitrogen (TDN) were 23±3 μg-at N 1−1 in the northern region (mouth) and 41±5 μg-at N 1−1 in the southern region (head) of the Gulf. Rates of nitrogen uptake, determined with15N-labeled substrates, reflected differences in TDN concentration between the regions. In May, uptake of DIN+DON measured 0.17 and 0.43 μg-at N 1−1 h−1 in the northern and southern parts of the Gulf, respectively. In July, DIN+D…

Depth profiling of Pu, 241Am and 137Cs in soils from southern Belarus measured by ICP-MS and alpha- and gamma-spectrometry

2003

The depth distribution of plutonium, americium, and Cs-137 originating front the 1986 accident at the Chernobyl Nuclear Power Plant (NPP) was investigated in several soil profiles in the vicinity from Belarus. The vertical migration of transuranic elements in soils typical of the 30 km relocation area around Chernobyl NPP was studied using inductively coupled plasma mass spectrometry (ICP-MS), alpha spectrometry, and gamma spectrometry. Transuranic concentrations in upper soil layers ranged from 6 x 10(-12) g g(-1) to 6 x 10(-10) g g(-1) for plutonium and from 1.8 x 10(-13) g g(-1) to 1.6 x 10(-11) g g(-1) for americium. These concentrations correspond to specific activities of Pu239+240 of…