Beryllium selenide

Beryllium sulfide, BeS beryllium selenide, BeSe beryllium telluride, BeTe beryllium polonide, BePo magnesium sulfide, MgS magnesium selenide, MgSe magnesium telluride, MgTe calcium sulfide, CaS (oldhamite) calcium selenide, CaSe calcium telluride, CaTe strontium sulfide, SrS strontium selenide, SrSe barium sulfide, BaS barium selenide, BaSe barium hydrosulfide, Ba(HS)2 barium hydrosulfide tetrahydrate, Ba(HS)2 H20. 

No experimental thermodynamic information is available for beryllium selenides. 

Beryllium selenide is prepared from the elements in a Hg stream at 1100°C. Pure Se and pure pulverized Be are placed in a quartz reaction tube in separate boats made of AlgO or BeO, (or at least of quartz). The hydrogen should pass first over the heated Se and then, when laden with Its vapor, over the Be. A wash bottle filled with lead acetate is mounted at the exit end of the reaction tube to absorb the very toxic HgSe present in the discharged gas. The Se is heated with a Bunsen burner the uniform heat of an electric furnace is required for the Be. The BeSe so obtained often shows a tendency to crystallize in long needles. 

Beryllium Selenide, Beryllium Telluride.—Preparation claimed by Wohler (1828 2), but probably he was mistaken. 

Beryllium selenide BeSe n F4Zm fee Zinc blende Fig. 4.1-131... 

Beryllium selenide BeSe a = 0.51520 (23) RT Epitaxial film, X-ray diffraction... 

Beryllium oxide Beryllium sulfide Beryllium selenide Beryllium telluride... 

The Transition to the Sphalerite Structure.—The oxide, sulfide and selenide of beryllium have neither the sodium chloride nor the cesium chloride structure, but instead the sphalerite or the wurzite structure. The Coulomb energy for the sphalerite arrangement is... 

It is also shown that theoretically a binary compound should have the sphalerite or wurzite structure instead of the sodium chloride structure if the radius ratio is less than 0.33. The oxide, sulfide, selenide and telluride of beryllium conform to this requirement, and are to be considered as ionic crystals. It is found, however, that such tetrahedral crystals are particularly apt to show deformation, and it is suggested that this is a tendency of the anion to share an electron pair with each cation. 

Using the periodic table if necessary, write formulas for the following compounds (a) hydrogen bromide, (b) magnesium chloride, (c) barium sulfide, (d) aluminum fluoride, (e) beryllium bromide, (/) barium selenide, and (g) sodium iodide. 

Water-free inorganic solvents, such as ammonia, sulfur dioxide, and hydrazine, have been tested in terms of their suitability for electrolytic metal deposition. Liquid ammonia is used for a series of electrolytic metal deposition processes. Besides the low boiling point (- 33 °C) of this solvent its toxicity is disadvantageous. It has been reported that group lA and IIA metals, such as hthium, sodium, magnesium, and beryllium can be deposited from solutions based on ammonia as a solvent [45]. However, only thin or incoherent layers are thus produced [43, 44]. Because it is possible to form anions of molybdenum, lead, selenium, and tellmium in anunonia, these elements can be anodically deposited. Thus, deposition of the semiconductor lead selenide has also been achieved with ammonia as a solvent. 

The a-furildioxime method has been used for determining nickel in silicate and sulphide minerals [16], tungsten selenide [83], steel [16], indium and aluminium [84], cadmium [85], alkalis [3], beryllium [86], rhenium [87], compounds of rare-earth elements [88,89], petroleum products [90], and boiler water [91]. 

Beryllium oxide, selenide, sulphide, and telluride, values of properties.. See Semiconductors Basis states, 5... 

Wohler (182812) thought he had prepared the selenide, telluride, arsenide and phosphide by fusing with the respective elements hut his observations have not been confirmed. Beryllium has probably never been obtained in combination with hydrogen although Winkler, (1891 3) thought he had produced a hydride. Beryllium unites directly with carbon, boron and silicon at the heat of the electric furnace (Ldieau, 1895 2, 1898 7, 1899 ii). It reduces SiCl when heated, (Rauter, 1892 2). 

---