Alkali metal amalgam, liquid

It is logical to consider the nncleophile, Nu-, as a source of the electron to be transferred onto the snbstrate molecnle, RX. However, in most cases, the nucleophile is such a poor electron donor that electron transfer from Nn- to RX is extremely slow, if it is possible at all. These reactions reqnire an external stimulation in which a catalytic amount of electrons is injected. Such kinds of assistance to the reactions from photochemical and electrochemical initiations or from solvated electrons in the reaction mediums have been pointed out earlier. Alkali metals in liquid ammonia and sodium amalgam in organic solvents can serve as the solvated electron sources. Light initiation is also used widely. However, photochemical initiation complicates the reaction performance. 

In Eqs. (122) and (123), M(Hg) is an alkali metal amalgam electrode, MX the solvated halide of the alkali metal M at concentration c in a solvent S, and AgX(s)/Ag(s) a silver halide-silver electrode. Equation (124) is the general expression for the electromotive force " of a galvanic cell without liquid junction in which an arbitrary cell reaction 0)1 Yi + 0)2Y2 + coiYi + , takes place between k components in v phases. In Eq. (124) n is the number of moles of electrons transported during this process from the anode to the cathode through the outer circuit, F the Faraday number, and the chemical potential of component Yi in phase p. Cells with liquid junctions require the electromotive force E in Eq. (124) to be replaced by the quantity E — Ej), where Ey> is the diffusion potential due to the liquid junction. The standard potential E° for the cell investigated by Eq. (122) is given by the relationship... 

Aryl ketones may be reduced to hydrocarbons by the Clemmensen reduction using zinc amalgam and HCI or by catalytic hydrogenolysis in the presence of palladium metal. Dissolving metal reduction of aromatic rings using an alkali metal in liquid ammonia gives 1,4-hexadienes. 

Rubidium can be liquid at room temperature. It is a soft, silvery-white metallic element of the alkali group and is the second most electropositive and alkaline element. It ignites spontaneously in air and reacts violently in water, setting fire to the liberated hydrogen. As with other alkali metals, it forms amalgams with mercury and it alloys with gold, cesium, sodium, and potassium. It colors a flame yellowish violet. Rubidium metal can be prepared by reducing rubidium chloride with calcium, and by a number of other methods. It must be kept under a dry mineral oil or in a vacuum or inert atmosphere. 

CHEMICAL PROPERTIES Hg Forms alloys with most metals except iron attacks most metals to form amalgams reacts violently with alkali metals, acetaldehyde, azides, ammonia gas, chlorine, chlorine dioxide, sodium carbide and ethylene oxide noncombustible liquid FP (not applicable) AT (not applicable) LFL (not applicable) UFL (not applicable). 

The most useful method for obtaining anionic metal carbonyl derivatives for preparative purposes is the reduction of various metal carbonyls with an alkali metal or amalgam, generally in the presence of a basic solvent such as liquid ammonia or various ethers. In order to minimize formation of metal... 

In thermally induced Sj l processes, the Nu" itself serves as the electron donor without external stimulation. However, in most cases, induced ET is necessary to initiate Sj l reactions. Different methodologies are used to initiate reactions, such as (i) photostimulated reaction, (ii) electrochemical initiation, (iii) inorganic salts (usually Fe ), and (iv) solvated electrons from alkali metal or sodium amalgam in liquid ammonia, among others. 

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