Examples of selenium- and tellurium-containing organic polymeric and oligomeric materials that have selenium or tellurium atoms in the backbone but not as a part of the heterocyclic ring are quite rare and will be discussed toward the end of this chapter.
The application of selenium in the responsive polymer system and the enzyme mimic system have been well studied. Our group initiated this line of research in 2009 by first extending selenium chemistry to dynamic chemistry.
Selenium dioxide is a colorless solid that consists of a one-dimensional polymeric chain with alternating atoms of selenium and oxygen. It is an acidic oxide and dissolves to form selenous acid. Selenium compounds are poisonous and contain a strong odor.
It exists as one dimensional polymeric chain with alternating selenium and oxygen atoms. * It sublimes readily and hence the commercial samples of SeO 2 can be purified by sublimation. * SeO 2 is an acidic oxide and dissolves in …
Selenium's wiki: Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It rarely oc
Organic compounds which contain selenium as an integral part of the molecule. | Explore the latest articles, projects, and questions and answers in Organoselenium Compounds, and find ...
Selenium's wiki: Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, and also has similarities to arsenic. It …
Selenium compounds can trap free radicals, thereby converting them into stable compounds. For human beings, selenium is an essential element, that plays a major role in many physiological and biochemical processes.
Because of selenium’s electronegativity and atomic radius, selenium-containing compounds exhibit unique bond energy (C–Se bond 244 kJ mol –1; Se–Se bond 172 kJ mol –1). These values give the C–Se or Se–Se covalent bonds dynamic character and make them responsive to mild stimuli.
A method of preparing monomeric and polymeric aromatic organic selenium compounds comprising reacting a suspension of finely divided selenium with an alkali metal in a polar aprotic solvent, wherein the molar ratio of alkali metal to selenium is about 2:1, to produce an alkali metal monoselenide reagent; and reacting said alkali …
Sigma-Aldrich Online Catalog Product List: Selenium Compounds
This invention constitutes a method for preparing molecular and polymeric aromatic selenide compounds such as bis-phenyl selenide and poly(p-phenylene selenide). The method comprises reacting an aryl halide with an alkali metal selenide reagent formed in an aprotic solvent.
Selenium is a nonmetallic chemical element found in trace amounts in human body. Selenium primarily occurs in vivo as selenocompounds, mostly selenoproteins such as glutathione peroxidase and thioredoxin reductase (enzymes responsible for detoxification). Alone or in combination with Vitamin E, selenocompounds act as antioxidants.
Jul 05, 1988· This invention constitutes a method for the synthesis of conjugated molecular and polymeric aromatic selenium compounds. The method involves the reaction of aromatic halides with an alkali metal monoselenide reagent such as Na 2 Se or K 2 Se.
In selenium: Compounds …with oxygen, it occurs as selenium dioxide, SeO 2 , a white, solid, chainlike polymeric substance that is an important reagent in organic chemistry. The reaction of this oxide with water produces selenious acid, H 2 SeO 3 .
9 Olaf Conrad, Christoph Jansen, Bernt Krebs, ChemInform Abstract: Boron-Sulfur and Boron-Selenium Compounds - From Unique Molecular Structural Principles to Novel Polymeric Materials, ChemInform, 2010, 30, 17, noWiley Online Library
Selenium is a chemical element with symbol Se and atomic number 34. It is a nonmetal with properties that are intermediate between the elements above and below in the periodic table , sulfur and tellurium . It rarely occurs in its elemental state or as pure ore compounds in the Earth's crust. Selenium ( Greek σελήνη selene meaning "Moon") was discovered in 1817 by Jöns Jacob Berzelius ...
The structure of black selenium is irregular and complex and consists of polymeric rings with up to 1000 atoms per ring. Black Se is a brittle, lustrous solid that is slightly soluble in CS 2. ... Selenium compounds commonly exist in the oxidation states −2, +2, +4, and +6. Chalcogen compounds.
Sulfur- and selenium-based linkers in polymer-supported organic synthesis JOVI TZE WAI KAN and PATRICK H. TOY* Department of Chemistry, The University of Hong Kong, Pokfulam Road, ... Compounds were released from the solid support by treatment with TFA in the presence of scavengers.
Selenium nanoparticles inhibit Staphylococcus aureus growth. Phong A Tran 1 and ... A bacterial biofilm is an aggregate of one or more types of bacteria in a hydrated polymeric matrix.2 Biofilms are a ... nanoparticles and their biological effects toward mammalian cells in vitro.15,16 Others reported inhibitory effects of selenium compounds ...
Low cytotoxic trace element selenium nanoparticles and their differential antimicrobial properties against S. aureus and E. coli ... compounds (such as chlorohexidine–silver sulfadiazine), one ... polymers are some of the most common polymeric materials
Selenium dioxide adopts a polymeric structure in the solid state; however, two reports suggest that this polymer may still serve as a source of molecular selenium oxides: The first report deals with the reaction of [Pt(PPh 3) 2 (η 2-CH 2 CH 2)] and selenium dioxide.
Apr 23, 1996· While most uses of the modified polymers to remove transition metals occur at optimum pH values of from about 6 to about 10, we have surprisingly found that the modified polymer treatment is more effective in the removal of selenium compounds when the water to be treated is acidic, having a pH value of about 5 or less.
Nanostructure selenium compounds as pseudocapacitive electrodes for high-performance asymmetric supercapacitor ... 2.0 mg) as well as 10 wt% polymer binder (polyvinylidene fluoride, 2 mg) were mixed with some N-methyl-2-pyrrolidone to ... Learn about displayed equations in Royal Society Open Science. Open science. ROYAL SOCIETY OPEN SCIENCE ...
The researchers used compounds with a positively polarised selenium atom. It forms a weak bond to the substrate of the reaction, the transformation of which was accelerated by 20 to 30 times as a ...
In combination with oxygen, it occurs as selenium dioxide, SeO 2, a white, solid, chainlike polymeric substance that is an important reagent in organic chemistry. The reaction of this oxide with water produces selenious acid, H 2 SeO 3 .
Selenium dioxide is the chemical compound with the formula SeO 2. This colorless solid is one of the most frequently encountered compounds of selenium. Selenium dioxide Names Other names ... The relative stereochemistry at Se alternates along the polymer chain (syndiotactic).
The application of selenium/tellurium containing polymers in fabricating functional nanomaterials is highlighted. • Selenium/tellurium chemistry can be used to construct stimuli-responsive systems with enhanced sensitivity.
6 SELENIUM IN NUTRITION CHEMISTRY OF SELENIUM-CONTAINING COMPOUNDS The chemistry of organic selenium compounds has been reviewed in detail by Klayman and Gunther (1973~.
Organic compounds in general have some reducing power and can in principle react with compounds in this class. Actual reactivity varies greatly with the identity of the organic compound. Inorganic oxidizing agents can react violently with active metals, cyanides, esters, and thiocyanates.