Search results for "element"
showing 10 items of 13601 documents
ChemInform Abstract: Sustainable Carbon-Carbon Bond Formation Catalyzed by New Oxamate-Containing Palladium(II) Complexes in Ionic Liquids.
2014
New and versatile bis(oxamato)palladate(II) complexes (I) are synthesized and investigated for both Suzuki and Heck coupling reactions in molten tetra-n-butylammonium bromide as ionic liquid.
ChemInform Abstract: α-Cyanation of Aromatic Tertiary Amines Using Ferricyanide as a Non-Toxic Cyanide Source.
2016
Aromatic tertiary amines, mostly isoquinoline derivatives and analogous N-heterocycles, are treated with the non-toxic agent (II) under conditions A) or B) to produce the desired N-aminonitrile compounds as amino acid precursors and as building blocks of complex nitrogen heterocycles.
ChemInform Abstract: Applications and Stereoselective Syntheses of P-Chirogenic Phosphorus Compounds
2016
Phosphorus compounds bearing chirality on the P-center are usually qualified as P-chirogenic or P-stereogenic. This chemical class concerns natural products, agrochemistry, molecular materials, biology and pharmacy, although it is certainly in coordination chemistry and in asymmetric catalysis using chiral transition metal complexes that P-chirogenic phosphorus compounds are the most used. The chiral phosphine ligands and their uses in asymmetric metal-catalyzed reactions have been widely reviewed in literature. However, an overview covering the applications as well as the stereoselective syntheses of all classes of phosphorus compounds has not yet been provided. This review reports the bes…
Darstellung und eigenschaften von formazanen aus polyacroleinen. Polymere acroleine, 17. Mitt.1
1960
Die Herstellung von verschiedenen, substituierten Polyacroleinphenylhydrazonen wird beschrieben. Durch Umsetzung mit Diazoniumsalzen entstehen Polymere mit Formazan-Gruppen. Diese lassen sich zu Tetrazolium-Gruppen dehydrieren. Die polymeren Formazane bilden bei geeigneten Substituenten mit Kupfer-und Uranyl-Ionen Komplexe und konnen daher als selektive Ionenaustauscher verwendet werden. Ferner werden einige polymere Azomethine beschrieben. The preparation of various substituted polyacroleinphenylhydrazones is reported. Polymers with formazane groups are obtained by the reaction of diazonium salts, which can be dehydrogenized to tetrazolium-groups. With suitable substitutes, the polymerie f…
Back Cover: Chemoselective, Substrate-directed Fluorination of Functionalized Cyclopentane β-Amino Acids (Chem. Asian J. 23/2016)
2016
<strong>Synthesis and Platinum (II) Complexes of Different Polyazacyclophane Receptors</strong>
2015
During the last years, research on coordination chemistry of platinum has aroused great interest due to their potential biological applications. Herein, we report the interaction of PtCI42- with different polyazacyclophanes containing a pyridine unit as aromatic spacer. Formation of complexes has been studied by 1H and 195Pt NMR spectroscopy. Analysis of the recorded spectra of D2O solutions containing L and PtCl42- in a 1:1 molar ratio at acidic pH shows the evolution with time of the 1H and 195Pt signals. Different crystal structures have been solved by X-ray diffraction analysis. At acidic pHs, the metal ion is coordinated by the central amino group of the macrocyclic cavity and three ch…
Reversible, room-temperature C—C bond activation of benzene by an isolable metal complex
2019
The activation of C-C bonds is of fundamental interest in the construction of complex molecules from petrochemical feedstocks. In the case of the archetypal aromatic hydrocarbon benzene, C-C cleavage is thermodynamically disfavored, and is brought about only by transient highly reactive species generated in situ. Here we show that the oxidative addition of the C-C bond in benzene by an isolated metal complex is not only possible, but occurs at room temperature and reversibly at a single aluminium center in [(NON)Al]- (where NON = 4,5-bis(2,6-diisopropylanilido)-2,7-di-tert-butyl-9,9-dimethylxanthene). Selectivity over C-H bond activation is achieved kinetically and allows for the generation…
Spectroscopic behaviour of metal–drug complexes. Infrared spectra of Cu(II) complexes with 5-amino-1,3,4-thiadiazole-2-thiol (Hatm)
1997
Abstract The infrared spectra of the drug Hatm and its copper (II) complexes with stoichiometry [Cu(atm) 2 (H 2 O)] and [Cu(Hatm)(HIm) 2 (SO 4 )] are reported and discussed. The Raman spectrum of Hatm is also reported. An assignment of Hatm, HIm, H 2 O and SO 4 modes in the complexes is proposed in comparison with the modes of the free ligands. Important information about the metal–ligand vibrations has been obtained.
Lithium Ion Recognition with Nanofluidic Diodes through Host-Guest Complexation in Confined Geometries
2018
[EN] The lithium ion recognition is receiving significant attention because of its application in pharmaceuticals, lubricants and, especially, in energy technology. We present a nanofluidic device for specific lithium ion recognition via host guest complexation in a confined environment. A lithium-selective receptor molecule, the aminoethyl-benzo-12-crown-4 (BC12C4-NH2), is designed and functionalized on single conical nanopores in polyethylene terephthalate (PET) membranes. The native carboxylic acid groups on the pore walls are covalently linked with the crown ether moieties and the process is monitored from the changes in the current voltage (I-V) curves. The B12-crown-4 moieties are kno…