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The hydride reacts with the weak Bronsted acid releasing H 2. Hydrides such as calcium hydride are used as desiccants, i.e. drying agents, to remove trace water from organic solvents. The hydride reacts with water forming hydrogen and hydroxide salt. The dry solvent can then be distilled or vacuum transferred from the "solvent pot".
An electric discharge through hydrogen gas at low pressure (20 pascals) containing pieces of magnesium can produce MgH. [7] Thermally produced hydrogen atoms and magnesium vapour can react and condense in a solid argon matrix. This process does not work with solid neon, probably due to the formation of MgH 2 instead. [8]
A metal hydride can be a thermodynamically a weak acid and a weak H − donor; it could also be strong in one category but not the other or strong in both. The H − strength of a hydride also known as its hydride donor ability or hydricity corresponds to the hydride's Lewis base strength. Not all hydrides are powerful Lewis bases.
Magnesium hydride is the chemical compound with the molecular formula MgH 2. It contains 7.66% by weight of hydrogen and has been studied as a potential hydrogen storage medium. It contains 7.66% by weight of hydrogen and has been studied as a potential hydrogen storage medium.
A molecular hydride may be able to bind to hydrogen molecules acting as a ligand. The complexes are termed non-classical covalent hydrides. These complexes contain more hydrogen than the classical covalent hydrides, but are only stable at very low temperatures. They may be isolated in inert gas matrix, or as a cryogenic gas.
The transition state of two transfer-hydrogenation reactions from ruthenium-hydride complexes onto carbonyls. Transfer hydrogenation uses hydrogen-donor molecules other than molecular H 2. These "sacrificial" hydrogen donors, which can also serve as solvents for the reaction, include hydrazine, formic acid, and alcohols such as isopropanol. [18]
Tungsten dihydride complexes can hydrogenate ketones stoichiometrically with no external acids. One hydride serves as the hydride source, and the other serves as a proton source. [2] In the case of ionic hydrogenation, a dihydride complex is regenerated by hydrogen gas following hydrogenation. Typical catalysts are tungsten or molybdenum complexes.
Potassium hydride is produced by direct combination of the metal and hydrogen at temperatures between 200 and 350 °C: 2 K + H 2 → 2 KH. This reaction was discovered by Humphry Davy soon after his 1807 discovery of potassium, when he noted that the metal would vaporize in a current of hydrogen when heated just below its boiling point. [4]: p.25