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Sample of cadmium selenide, a pigment. The parent inorganic selenide is hydrogen selenide (H 2 Se). It is a colorless, malodorous, toxic gas. It dissolves in aqueous solution, to give the hydrogenselenide or biselenide ion HSe −. At higher pH, selenide forms. Solutions of hydrogen selenide and selenide are oxidized by air to give elemental ...
One example is dimethylselenide ((CH 3) 2 Se). These are the most prevalent organoselenium compounds. Symmetrical selenides are usually prepared by alkylation of alkali metal selenide salts, e.g. sodium selenide. Unsymmetrical selenides are prepared by alkylation of selenoates.
Sodium benzeneselenolate; Trimethylsilyl phenyl selenide; The most common oxidizing agent employed is hydrogen peroxide (H 2 O 2). [9] It is sometimes used in excess, to overcome catalytic decomposition of H 2 O 2 by selenium; however, undesired oxidation of starting material has been observed under these conditions.
Sodium selenide is an inorganic compound of sodium and selenium with the chemical formula Na 2 Se. Preparation. This colourless solid is prepared by the reaction of ...
Hydrogen selenide is an extremely toxic, corrosive gas. [21] Selenium also occurs in organic compounds, such as dimethyl selenide, selenomethionine, selenocysteine and methylselenocysteine, all of which have high bioavailability and are toxic in large doses.
The Shorigen reaction is also used in the generation of phenylsodium, where an alkyl sodium compound is treated with benzene: [3] RNa + C 6 H 6 → RH + C 6 H 5 Na. The method can also result in the addition of a second sodium. This dimetallation occurs in the meta and para positions. The use of certain alkyl sodium compounds such as n-amyl ...
For example, benzeneselenol is generated by the reaction of phenylmagnesium bromide with selenium followed by acidification: [8] Another preparative route to selenols involves the alkylation of selenourea, followed by hydrolysis. Selenols are often generated by reduction of diselenides followed by protonation of the resulting selenolate:
Selenium is toxic in high concentrations. As sodium selenite, the chronic toxic dose for human beings was described as about 2.4 to 3 milligrams of selenium per day. [7] In 2000, the US Institute of Medicine set the adult Tolerable upper intake levels (UL) for selenium from all sources - food, drinking water and dietary supplements - at 400 μg/day. [8]