kosmos: Selenium

Evidence: 100 • authority: 72

Selenium is a chemical element; it has symbol Se and atomic number 34. It has various physical appearances, including a brick-red powder, a vitreous black solid, and a grey metallic-looking form. It seldom occurs in this elemental state or as pure ore compounds in Earth's crust. Selenium (from σελήνη 'moon') was discovered in 1817 by Jöns Jacob Berzelius, who noted the similarity of the new element to the previously discovered tellurium (named for the Earth). Selenium is found in metal sulfide ores, where it substitutes for sulfur. Commercially, selenium is produced as a byproduct in the refining of these ores. Minerals that are pure selenide or selenate compounds are rare. The chief commer…

Evidence: 59 • authority: 88

ChemInform Abstract: HIGH TEMPERATURE SOLID STATE CHEMISTRY OF RARE EARTH COMPOUNDS WITH VALENCE INSTABILITY: NONSTOICHIOMETRIC THULIUM‐SELENIDE (TMSE) AND MIXED CRYSTALS. Abstract TmxSe (0.6 x 1.2) und die neuen Mischkristallreihen TmSe,‐xTex und Tm1‐xEuxSe werden als typische Vertreter von Verbindungen mit Valenzinstabilität vorgestellt.

Evidence: 59 • authority: 92

Total synthesis of marine cyclopeptide largamides B and H, and tiglicamide B.. Largamides A–H and tiglicamides A–C comprise a rare class of marine-derived cyclic peptides characterized by protease inhibitory activity and highly intricate molecular architectures. Their pronounced biological relevance, coupled with their limited natural abundance, has rendered these compounds longstanding and compelling targets for total synthesis. In this study, we report comprehensive synthetic investigations of largamides B and H, together with the first total synthesis and biological evaluation of tiglicamide B as a novel inhibitor of nitric oxide (NO) production. Our synthetic strategy employs carefully…

Evidence: 59 • authority: 88

ChemInform Abstract: THE INTERACTION OF AROMATIC HYDROCARBONS WITH ORGANOMETALLIC COMPOUNDS OF THE MAIN GROUP ELEMENTS. IV. THE PREPARATION AND STRUCTURE OF THE NOVEL SELENIDE, , POTASSIUM METHYLTRIS(TRIMETHYLALUMINUM)SELENATE‐BISBENZENE. Abstract Aus dem Salz (I) wird mit Trimethylaluminium (II) in einem geschlossenen System der Komplex (III) erhalten, aus dem das unbeständige Selenid (IV) beim Erhitzen gebildet wird.

Evidence: 58 • authority: 80

Studies on selenium-related compounds VI. Biosynthesis of dimethyl selenide in rat liver after oral administration of sodium selenate*1