Reactions with Alkali and Alkaline Earth Metals

Reactions with Alkali and Alkaline Earth Metals 

Step-wise replacement of all three hydrogen atoms in phosphine by lithium can be obtained by the reaction of phosphine with an alkyl lithium compound in the corresponding molar ratio. The preparations of LiaP and Na3 from the elements were described by Brauer and Zintl.  

Potassium dihydrogenphosphide dissolved in dimethylformamide, is probably dissociated into ions. This is confirmed by the equivalent conductance, the value of 77.0 f2 cm mol was found for a 8 10 mol/cm solution. The PH2 ion is a strong nucleophilic reagent. The study of its chemical behaviour towards oxygen, sulphur and white phosphorus has produced, to date, no conclusive results. The reaction with the latter element results in the formation of an amorphous red-brown substance of composition KPsH2 which is soluble in dimethylformamide.  

LiaP and NaaP have the same structure as NaaAs. Each phosphorus atom is surrounded by 5 alkali metal ions at the comers of a trigonal bipyramid. The lattice contains two types of alkali metal atoms. One sort is surrounded by a trigonal prism of other alkali metal ions, in which the centres of the three vertical faces of the prism are occupied by three phosphorus atoms. The other type of alkali metal ion is surrounded by 4 phosphorus atoms in a distorted tetrahedron. Seven alkali metal ions are found at larger distances. In sodium phosphide the distance between the central phosphorus atom of the trigonal bipyramid and an axial sodium atom is 2.93 A and that between the phosphorus atom and an equatorial sodium atom 2.88 A 

As well as for the preparation of alkali phosphides, the reaction of phosphine with the elements, their oxides or halides, at higher temperatures in quartz tubes have been much used recently for the preparation of other phosphides, in particular those which play important roles in semi-conductor technology. The preparations of the following phosphides using these methods have been described for example, NdP 3s 36) 3p 137,138) Q p 139.140) SmP, LaP 136,141) TiP, Ti2P (possibly TisP) and InP See also Section IV.9. 

The flame reactions of alkali metal vapors (Li, Na, Cs) with nitrogen trifluoride between about 500 and 1000 K and at a few Torr show strong chemiluminescence. The emission results from electronically excited alkali metal atoms. Photon yields of up to 3% were measured. The excitation mechanism was assumed to involve the formation of an excited species and the transfer of energy from this species to the alkali metal atom (A) according to the simplified sequence [1,2] A +NF,- AF(v) +NF,,  

Emissions from electronically excited CN molecules (and Li atoms) were observed in the ternary Li-NFg-CCU flame system [3]. No difference in the chemiluminescence was seen in the Na-NF3 N20 system compared to the Na-Np3 system. However, in the CS-NF3 flame system, NO (A Z+ X n) emission together with emission from the Cs atom were observed. The NO emission was probably caused by O2 impurities in the gases [4]. 

Chemiluminescence spectra of BaF result from the flame reaction of barium vapor and nitrogen trifluoride. The highest photon yield measured was 50% at 2 Torr [7] whereas the corresponding quantity in the Mg + NF3 reaction was 3x10 % at 100 Torr [8]. 

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Reactions with alkali and alkaline earth metal hydrides also produce the same ionic metallic hydrazides ... 

At almost the same time as other polymer-supported phase transfer catalysts were first reported, polymer-supported solvents and cosolvents were found to be effective catalysts for phase transfer reactions 155-156>. Dipolar aprotic solvents such as hexa-methylphosphoramide (HMPA)157, dimethylsulfoxide (DMSO)158), and tertiary amides159,1601 are well known to coordinate strongly with alkali and alkaline earth metal cations, and hence promote nucleophilic displacement reactions of the anions161). Catalysts 44 155-162>163> and 45163),... 

With some catalyst systems, selectivity to primary metathesis products is near 100%, but side reactions (double-bond migration, dimerization, cyclopropanation, polymerization) often reduce selectivity. Such side reactions, such as oligomerization and double-bond shift over oxide catalysts, may be eliminated by treatment with alkali and alkaline-earth metal ions.26... 

As already known (Addison Logan 1964), anhydrous nitrates exhibit oxidizing properties. Their oxidizing activity increases from ionic nitrates with alkali and alkaline earth metal cations to covalent nitrates with transient metal cations. Oxidation reactions result in the formation of nitrogen-containing oxides. Depending on the kind of nitrate salt and on the reaction conditions, one of these oxides can be predominant. Organic substrates can evidently serve as reductant. 

All the arsinic acids dealt with in the following pages arc crystalline solids. Some of tlie primary acids, when heated above their melting-points, eliminate water and form anliydrides. The acids are very stable but may be reduced by amalgamated zinc dust and hydrochloric acid, or by electrolysis in aqueous alcoholic hydrochloric acid, to arylarsines, RAsIIs- An exception to tlie above-mentioned stability is the case of benzylarsinic acid, which is decomposed by mineral adds, and differs from all other members of this series in its reactions. The salts formed with alkali and alkaline earth metals show that the acids are dibasic. Esters may be formed by heating the silver salts of tlie acids in ethereal solution under reflux with the calculated amount of alkyl iodide, but excess of the latter must be avoided or alkyi-arylarsenites are formed ... 

Due to the inherent limitation of those functional groups that react with alkali and alkaline-earth metals, postpolymerization is applicable to a broad range of functionalization. The most important issue in these reactions is the possibility of side reactions that break down the Si-Si bonds in organosilicon molecules... 

The preparation of soda and lime bleaches (sodium and calcium hypochlorite) is typical of reactions of chlorine with alkalis and alkaline earth metal hydroxides. The hypochlorites formed are powerfiil oxidizing agents. Because of its great affinity for hydrogen, chlorine removes hydrogen from some compounds such as its reaction with hydrogen sulfide to form hydrochloric acid and sulfur. 

Although non-ionic surfactants would appear to be unlikely candidates as complexing agents for metal ions, the interaction of some polyoxyethylene glycols with metal ions has recently attracted interest [90,91]. The reaction of non-cyclic polyoxyethylene derivatives with alkali and alkaline earth metals has been studied by means of solvent extraction of their thiocyanates or iodides. Polyoxyethylene dodecyl ethers with more than 7 ethylene oxide units were able to bind potassium ion in the water phase and to transfer the complexed salt to the organic phase the extracting power of Ci2Eg was about one sixth of that of a crown ether [92]. Some results are shown in Fig. 11.13. 

Reactions of 44 with alkali and alkaline-earth metal cations are accompanied by considerable displacement of tautomeric equilibrium toward enolimine complexes 45 K. The intensity of the absorption maximum at 480 nm (corresponding to the tautomer K) in the electronic spectra decreases by 25% for alkaline-earth and 15% for alkali metal cations with the subsequent increase of intensity of the 420 nm absorption band. Compound 44 showed high sensitivity for Cu and Co " " ions. Acetonitrile and dimethyl sulfoxide solutions of 44 exhibit strong fluorescence with maximum at 530 nm. Addition of Cu " and Co " " leads to the formation of chelates 46 demonstrating pronounced naked-eye CHEQ effect the fluorescence intensity decreased by a factor of 39 and 33, respectively, without any appreciable shift of the emission maximum (Figure 10.30). 

Chemical Properties. In addition to the reactions Hsted in Table 3, boron trifluoride reacts with alkali or alkaline-earth metal oxides, as well as other inorganic alkaline materials, at 450°C to yield the trimer trifluoroboroxine [13703-95-2] (BOF), MBF, and MF (29) where M is a univalent metal ion. The trimer is stable below — 135°C but disproportionates to B2O2 and BF at higher temperatures (30). 

Explosive reactions can occur between oxygen and a wide range of chemicals including organic compounds (such as acetone, acetylene, secondary alcohols, hydrocarbons), alkali and alkaline earth metals, ammonia, biological specimens previously anaesthetized with ether, hydrogen and foam rubber. 

The in-out bicyclic amines prepared by Simmons and Park bear a remarkable semblance to the cryptands but lack the binding sites in the bridges. As a result, these molecules interact with electrophiles in a fashion similar to other tertiary amines and generally do not exhibit strong interactions with alkali or alkaline earth metal ions. The in-out bicyclic amines are prepared by reaction of the appropriate acid chlorides and amines in two stages to yield the macrobicyclic amine after reduction of the amidic linkages. A typical amine is shown above as compound 18. 

Section 20.1 deals with the processes by which these metals are obtained from their principal ores. Section 20.2 describes the reactions of the alkali and alkaline earth metals, particularly those with hydrogen, oxygen, and water. Section 20.3 considers the redox chemistry of the transition metals, their cations (e.g., Fe2+, Fe3+), and their oxoanions (e.g., Cr042-). ... 

The compounds formed by the reaction of hydrogen with the alkali and alkaline earth metals contain H- ions for example, sodium hydride consists of Na+ and H- ions. These white crystalline solids are often referred to as saline hydrides because of their physical resemblance to NaCL Chemically, they behave quite differently from sodium chloride for example, they react with water to produce hydrogen gas. Typical reactions are... 

Foreign cations can increasingly lower the yield in the order Fe, Co " < Ca " < Mn < Pb " [22]. This is possibly due to the formation of oxide layers at the anode [42], Alkali and alkaline earth metal ions, alkylammonium ions and also zinc or nickel cations do not effect the Kolbe reaction [40] and are therefore the counterions of choice in preparative applications. Methanol is the best suited solvent for Kolbe electrolysis [7, 43]. Its oxidation is extensively inhibited by the formation of the carboxylate layer. The following electrolytes with methanol as solvent have been used MeOH-sodium carboxylate [44], MeOH—MeONa [45, 46], MeOH—NaOH [47], MeOH—EtsN-pyridine [48]. The yield of the Kolbe dimer decreases in media that contain more than 4% water. 

That eh is the intermediate species and not the H atom has been verified by adding NzO and methanol to water then, N2, not H2, is the principal product. Alkali and alkaline earth metals above Na in the electrochemical series will also generate eh on dissolution in water. Moreover the H/D isotope effect in water containing 50% D is consistent with the reaction 2eh—H2 + 20H (Anbar and Meyerstein, 1966 Hart and Anbar, 1970). 

Up till now anionic mercury clusters have only existed as clearly separable structural units in alloys obtained by highly exothermic reactions between electropositive metals (preferably alkali and alkaline earth metals) and mercury. There is, however, weak evidence that some of the clusters might exist as intermediate species in liquid ammonia [13]. Cationic mercury clusters on the other hand are exclusively synthesized and crystallized by solvent reactions. Figure 2.4-2 gives an overview of the shapes of small monomeric and oligomeric anionic mercury clusters found in alkali and alkaline earth amalgams in comparison with a selection of cationic clusters. For isolated single mercury anions and extended network structures of mercury see Section 2.4.2.4. 

The compositions of biomass among fuel types are considerably varied, especially with respect to inorganic constituents important to the critical problems of fouling and slagging. Alkali and alkaline earth metals, in combination with other fuel elements such as silica and sulfur, and facilitated by the presence of chlorine, are responsible for many imdesirable reactions in combustion furnaces and power boilers. 

Besides oxidative coupling of methane and double bond isomerization reactions (242), a limited number of organic transformations have been carried out with alkali-doped alkaline earth metal oxides, including the gas-phase condensation of acetone on MgO promoted with alkali (Li, Na, K, or Cs) or alkaline earth (Ca, Sr, or Ba) (14,120). The basic properties of the samples were characterized by chemisorption of CO2 (Table VI). 

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