Alkali metal halides, insoluble

The chief contaminants of organoalkalis made from organic halides with alkali metals [Eq. (a)] are the alkali-metal halide and unreacted alkali metal. For such organoalkalis as n-pentylsodium, which is insoluble in all solvents with which it does not react, there is no known method of purification of the product made by Eq. (a). 

Silicon dioxide, one of the products of this interaction, is insoluble in pure alkali metal halides and separates from the molten medium owing to the difference in densities. Thermodynamic analysis of the processes of molten iodide purification with different halogenating agents shows that their effectiveness reduces in the sequence SH4 > HI >h [294], An obvious advantage of silicon halides for the purification of halide melts used for singlecrystal growth is the fact that their use does not result in the appearance of additional impurities in the purified melts, since these processes are usually performed in quartz (Si02) vessels-reactors. 

Water and the alcohols are difficult to use as solvents in IR spectrometry. Water shows several strong absorption bands in the IR region, as can be seen in Figure 17-2. Here, the spectrum of water is shown along with the spectrum of an aqueous solution of aspirin. The computer-calculated difference spectrum reveals the spectrum of the water-soluble aspirin. Water and alcohols also attack alkali-metal halides, the most common materials used for cell windows. Hence, water-insoluble window materials, such as barium fluoride, must be used with such solvents. Care must also be taken to dry the solvents shown in Figure 17-1 before use with typical cells. 

The solubilities of inorganic substances in HF resemble those in water, with some marked differences. Most elements are not dissolved, except the active metals, which react with evolution of hydrogen gas. Alkali metal and some alkaline earth salts are soluble, but many react liberating weaker acids in solution. Alkali metal halides evolve the nearly insoluble hydrogen halides. Salts of transition metals are at most... 

Compounds of Tl have many similarities to those of the alkali metals TIOH is very soluble and is a strong base TI2CO3 is also soluble and resembles the corresponding Na and K compounds Tl forms colourless, well-crystallized salts of many oxoacids, and these tend to be anhydrous like those of the similarly sized Rb and Cs Tl salts of weak acids have a basic reaction in aqueous solution as a result of hydrolysis Tl forms polysulfldes (e.g. TI2S3) and polyiodides, etc. In other respects Tl resembles the more highly polarizing ion Ag+, e.g. in the colour and insolubility of its chromate, sulfide, arsenate and halides (except F), though it does not form ammine complexes in aqueous solution and its azide is not explosive. 

Rubidium metal alloys with the other alkali metals, the alkaline-earth metals, antimony, bismuth, gold, and mercury. Rubidium forms double halide salts with antimony, bismuth, cadmium, cobalt, copper, iron, lead, manganese, mercury, nickel, thorium, and zinc. These complexes are generally water insoluble and not hygroscopic. The soluble rubidium compounds are acetate, bromide, carbonate, chloride, chromate, fluoride, formate, hydroxide, iodide,... 

Unlike boron, aluminum, gallium, and indium, thallium exists in both stable univalent (thallous) and trivalent (thallic) forms. There are numerous thallous compounds, which are usually more stable than the corresponding thallic compounds. The thallium(I) ion resembles the alkali metal ions and the silver ion in properties. In this respect, it forms a soluble, strongly basic hydroxide and a soluble carbonate, oxide, and cyanide like the alkali metal ions. However, like the silver ion, it forms a very soluble fluoride, but the other halides are insoluble. Thallium(III) ion resembles aluminum, gallium, and indium ions in properties. 

All halides of alkali metals, except Li, are practically insoluble in pyridine this situation is... 

Beryllium reacts with fused alkali halides releasing the alkali metal until an equilibrium is established. It does not react with fused halides of the alkaline-earth metals to release the alkaline-earth metal. Water-insoluble fluoroberyllates, however, are formed in a fused-salt system whenever barium or calcium fluoride is present. Beryllium reduces halides of aluminum and heavier elements. Alkaline-earth metals can be used effectively to reduce beryllium from its halides, but the use of alkaline-earths other than magnesium [7439-95 4] is economically unattractive because of the formation of water-insoluble fluoroberyllates. Formation of these fluorides precludes efficient recovery of the unreduced beryllium from the reaction products in subsequent processing operations. 

There are two principal synthetic routes to dicarboxylate complexes. One of these uses an aqueous solution of the alkali metal dicarboxylate and the corresponding metal halide,93 while the other depends upon the dicarboxylic acid reduction of higher oxidation state metals. This reductive property of oxalic acid results in its ready dissolution of iron oxides and hence a cleaning utility in nuclear power plants.94 Mention must also be made of the successful ligand exchange synthesis of molybdenum dicarboxylates, Mo(dicarboxylate)2 H2 O, from the corresponding acetate complex. Unfortunately the polymeric, amorphous and insoluble nature of these complexes has restricted the study of these systems, which may well provide examples of multiple M—M bonding in dicarboxylate coordination chemistry.95... 

The lanthanide halides are usually bi(cyclopentadienyl) and related lanthanide complexes M is an alkali metal or silver, and A is an anionic transition metal carbonyl compound or tetraphenyl borate. The formation of the insoluble salt MX is a driving force for this reaction. 

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