Alkaline Halide Examples

The main example presented will be the alkaline-hypohalite method as it is the easiest to acquire the necessary chemicals. It Is of interest to note that the alkaline-halide method is much easier to perform, process- wise, in that it is more forgiving of sloppy technique. 

Aromatic halides (example 21, Table VII) also react in the presence of Ni(0) complexes in alkaline media. Complex nickel carbonyl anions, such as Ni5(CO),22, Ni6(CO)122, Ni9(CO)182 (194) are formed which, being more nucleophilic, can attack aromatic halides. 

Although the motion of protons does not lead to electrical conduction in the case of benzoic acid, electronic and even ionic conductivity can be found in other molecular crystals. A well-studied example of ionic conduction is a film of polyethylene oxide (PEO) which forms complex structures if one adds alkaline halides (AX). Its ionic conductivity compares with that of normal inorganic ionic conductors (log [cr (Q cm)] -2.5). Other polymers with EO-units show a similar behavior when they are doped with salts. Lithium batteries have been built with this type of... 

All the above-said concerns alkali-metal carbonates dissolved in melts based on alkaline- and alkaline-earth metal halides. It should be mentioned that there is a lack of data on the behaviour of alkaline-earth carbonates, in high-temperature alkaline halide melts. Nevertheless, these data are necessary, in particular, for the purification of halide melts. For example, it is known that alkaline-earth oxides possess appreciable solubilities in molten alkaline halides, and that they can be used for precipitation of less soluble transition metal-oxides. After such a precipitation, the excess of alkaline-earth oxide remains in the dissolved state. The question arises, therefore, whether it can be removed from the halide melt by passing C02 according to the conventional reaction... 

The outer-sphere coordination of OAc ligands in cluster 6 is in line with the ease of their replacement by another anions. This cluster can be precipitated from aqueous solution by various salts, e.g., alkaline halides, perchlorate, and fluoro-phosphate. For example, complete substitution of OAc anions, accompanied by some hydrolysis, was observed on treatment of a solution of cluster 6 with K[ PF ] to form a cluster with the idealized formula Pd56iphen6o06o(PF6)6o (7) ... 

Of course, the chemistry of zirconium cluster phases has been well described and reviewed in the literature [1-4]. Apart from a very few examples, mostly in the binary halides, almost all reduced zirconium halides contain octahedra of zirconium atoms centred on an interstitial atom Z. Several possible and experimentally realized Z include H, Be-N, K, Al-P, and the transition metals Mn-Ni. All these compounds have the general formula Ax"[(Zr6Z)Xi2X[J], with a " = alkali or alkaline earth metal cation, X=C1 Br or I, X =inner edge-bridging halide [5], X =outer exo-bonded halide, and 0[Pg.61]

Reactions of alcohols, ethers, and aliphatic halides with carbon monoxide were described as far back as 1948-1953 (173, 195). High pressure and temperature were required, however, for these processes. The use of alkaline media allowed carbonylation of alkyl iodides under mild conditions (example 22, Table VII). More recently, carbonylation of alkyl-nickel complexes was reported (example 26, Table VII). 

As the last example of C-C bond-formation reactions catalyzed by alkaline earth hydroxides, we mention the recently reported a-arylation of diethyl malonate in the presence of a palladium catalyst and a base in a separate phase 299). The arylation of carbonyl compounds is a carbon-carbon coupling reaction between an aryl halide and an enolate, which is usually catalyzed by palladium salts in the presence of an appropriate base (300,301). The arylation of diethyl malonate with bromobenzene (Scheme 48) was performed with tetrachloropalladate as the... 

Alkaline-Earth Sulfides and Sulfoselenides. Activated alkaline-earth sulfides have been known for a long time their luminesence is very varied. Emission bands between the ultraviolet and near infrared can be obtained by varying the activation. They are produced by precipitation of sulfates or selenites from purified solutions, followed by reduction with Ar-H2. The addition of activators, for example, copper nitrate, manganese sulfate, or bismuth nitrate, is followed by firing for 1 - 2 h. Alkaline-earth halides or alkali-metal sulfates are sometimes added as fluxes. 

A variation of the above tests is that devised by Lenher.1Ms which depends on tho low solubility of certain metal ions in alkaline solution. Treatment of an epoxide with concentrator aqueous man ganoua chloride, for example, causes the gradual appearance of a manganous hydroxide precipitate as OH ions are liberated (Eq. SS i). Other halides examined by Lenher but found to he less effective wore nine chloride, ferrous chloride, and stannous chloride. 

The majority of inorganic systems reported to exhibit photochromism are solids, examples being alkali and alkaline earth halides and oxides, titanates, mercuric chloride and silver halides.184 185 The coloration is generally believed to result from the trapping of electrons or holes by crystal lattice defects. Alternatively, if the sample crystal is doped with an impurity capable of existing in variable oxidation states (i.e. iron or molybdenum), an electron transfer mechanism is possible. 

Alkali metal halides can be volatile at incineration temperatures. Rapid quenching of volatile salts results in the formation of a submicrometer aerosol which must be removed or else exhaust stack opacity is likely to exceed allowed limits. Sulfates have low volatility and should end up in the ash. Alkaline earths also form basic oxides. Calcium is the most common and sulfates are formed ahead of halides. Calcium carbonate is not stable at incineration temperatures (see Calcium compounds). Transition metals are more likely to form an oxide ash. Iron (qv), for example, forms ferric oxide in preference to halides, sulfates, or carbonates. Silica and alumina form complexes with the basic oxides, eg, alkali metals, alkaline earths, and some transition-metal oxidation states, in the ash. 

In addition to the bimetallic complexes of rhenium and alkaline metals formed as byproducts in the exchange reactions of rhenium halids with alkali alkoxides (such as, for example, LiReO(OPr )5 xLiCl(THF)2 [519]) there has been recently prepared a number ofbimetallic complexes ofrhenium and molybdenum, rhenium and tungsten, and rhenium and niobium [904, 1451]. The latter are formed either due to the formation of a metal-metal bond, arising due to combination of a free electron pair on rhenium (V) and a vacant orbital of molybdenum (VI) atom or via insertion of molybdenum or tungsten atoms into the molecular structure characteristic of rhenium (V and VI) oxoalkox-ides. The formation of the compounds with variable composition becomes possible in the latter case. 

---