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Ionic hydrides are used as bases and, occasionally, as reducing reagents in organic synthesis. [12] C 6 H 5 C(O)CH 3 + KH → C 6 H 5 C(O)CH 2 K + H 2. Typical solvents for such reactions are ethers. Water and other protic solvents cannot serve as a medium for ionic hydrides because the hydride ion is a stronger base than hydroxide and most ...
The hydrogen anion, H −, is a negative ion of hydrogen, that is, a hydrogen atom that has captured an extra electron. The hydrogen anion is an important constituent of the atmosphere of stars, such as the Sun. In chemistry, this ion is called hydride. The ion has two electrons bound by the electromagnetic force to a nucleus containing one proton.
Binary hydrogen compounds in group 1 are the ionic hydrides (also called saline hydrides) wherein hydrogen is bound electrostatically. Because hydrogen is located somewhat centrally in an electronegative sense, it is necessary for the counterion to be exceptionally electropositive for the hydride to possibly be accurately described as truly behaving ionic.
In lithium aluminium hydride, the [AlH 4] − anion carries hydridic centers firmly attached to the Al(III). Although hydrides can be formed with almost all main-group elements, the number and combination of possible compounds varies widely; for example, more than 100 binary borane hydrides are known, but only one binary aluminium hydride. [16]
A celebrated example is K 2 ReH 9, a salt containing two K + ions and the ReH 9 2− anion. Other homoleptic metal hydrides include the anions in Mg 2 FeH 6 and Mg 2 NiH 4. Some of these anionic polyhydrides satisfy the 18-electron rule, many do not.
The concentration of hydrogen ions and pH are inversely proportional; in an aqueous solution, an increased concentration of hydrogen ions yields a low pH, and subsequently, an acidic product. By definition, an acid is an ion or molecule that can donate a proton, and when introduced to a solution it will react with water molecules (H 2 O) to ...
In general, complex metal hydrides have the formula M x M' y H n, where M is an alkali metal cation or cation complex and M' is a metal or metalloid.Well known examples feature group 13 elements, especially boron and aluminium including sodium aluminium hydride, NaAlH 4), lithium aluminium hydride, LiAlH 4, and lithium borohydride, (LiBH 4).
The helium hydride ion HeH + has been known since 1925. [70] The protonated dihelium ion He 2 H + can be formed when the dihelium cation reacts with dihydrogen: He + 2 + H 2 → He 2 H + + H. This is believed to be a linear molecule. [70] Larger protonated helium cluster ions exist He n H + with n from 3 to 14. He 6 H + and He 13 H + appear to ...