نتایج جستجو برای: samarium
تعداد نتایج: 1033 فیلتر نتایج به سال:
The mixed-metal rare-earth polyphosphate LiSm(PO(3))(4) consists of a three-dimensional framework in which zigzag [(PO(3))(n)](n-) chains with a periodicity of four PO(4) tetrahedra are connected through Li(+) and Sm(3+) ions (both with 2. symmetry).
Limits are imposed upon the possible rate of change of extra spatial dimensions in Kaluza-Klein and superstring theories by considering the consequences of such changes for primordial nucleosynthesis and the positioning of nuclear resonance levels in samarium, carbon, and oxygen. Previous limits from nucleosynthesis had not included strong-interaction effects. The strongest limits constrain the...
Cyclic hydrazones are efficient ketyl radical acceptors in reductive coupling cyclizations mediated by samarium diiodide, affording cyclic amino alcohols with controlled stereochemistry at the new aminated stereocenter. This approach has been successfully applied to the stereoselective synthesis of a fully functionalized trehazolin cyclitol starting from D-glucose, where the required cyclic hyd...
In this review, we give an overview of the properties and applications of samarium monosulfide, SmS, which has gained considerable interest as a switchable material. It shows a pressure-induced phase transition from the semiconducting to the metallic state by polishing, and it switches back to the semiconducting state by heating. The material also shows a magnetic transition, from the paramagne...
The first synthesis of the racemic 8-deoxy WP3688-2 angucycline antibiotic (3), with characteristic cis-hydroxy groups at C-4 a and C-12b, is reported. Key steps involve the coupling, mediated by samarium diiodide, of the bicyclic trione 37 to the tricyclic cis-diol 39. Biomimetic aldol cyclization of the corresponding dione 41 gave a mixture of the tetracyclic cis- and trans-3,4a-diols 42 and ...
New complexes of samarium(III), gadolinium(III), and dysprosium(III) with coumarin-3-carboxylic acid (HCCA) were prepared by the reaction of the ligand with respective metal nitrates in ethanol. The structures of the final complexes were determined by means of physicochemical data, elemental analysis, IR and Raman spectra. The metal-ligand binding mode in the new Ln(III) complexes of coumarin-3...
Development of lanthanide detoxification agents and protocols is of great importance in management of overdoses. Due to safety of maltol as a detoxifying agent in metal overloads, it can be used as a lanthanide detoxifying agent. In order to demonstrate the biodistribution of final complex, [(153)Sm]-samarium maltolate was prepared using Sm-153 chloride (radiochemical purity >99.9%; ITLC and sp...
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