Diamines, sodium ions

The reason for so many sodium ions in diamines can be explained as follows. Diamine is prepared by reduction of dinitro-compoundsCV). The diamine then reacts with hydrochloric acid ... 

Figure 5.21 Change in transport number of nitrate ions relative to chloride ions with the number of methylene groups of a, co-diamines. ( ) Concentration of Na+, 0.01 N (A) concentration of Na+, 0.04 N. The transport number of nitrate ions relative to chloride ions was measured using a 1 1 mixed salt solution of sodium nitrate and sodium chloride (concentration of sodium ions 0.01 or 0.04 N) at a 0.10 mA cm 2 for 60 min at 25.0 °C under vigorous agitation.

Ion Exchangers. Ion exchangers, resin or zeolite, have been judged most advantageous for use against ammonia, concentrated sulphuric acid, sodium hydroxide, potassium cyanide, cadmium chloride, oxalic acid, ethylene diamine, sodium alkylbenzenesulfonates, and phenol. They are sorbents for the ionic, most polar, and soluble solutes and complement polymeric sorbents for covalent nonmixers. 

Macrocycles have been prepared by formation of macrocyclic imines as well as by using variations of the Williamson ether synthesis ". Typically, a diamine or dialdehyde is treated with its counterpart to yield the Schiff s base. The saturated macrocycle may then be obtained by simple reduction, using sodium borohydride, for example. The cyclization may be metal-ion templated. In the special case of the all-nitrogen macrd-cycle, 15, the condensation of diamine with glyoxal shown in Eq. (4.14), was unsuccess-ful ... 

A synthesis of 5-(aioylamino)-2-aryloxazoles 39 is outlined in Scheme 9. Heating the glycol 37 (Bt = benzotriazol-l-yl), prepared from glyoxal and benzotriazole, with an amide in the presence of an ion exchange resin yields the acylated diamine 38, which cyclises by the action of sodium hydiide in DMF <95JHC1651>. 

Rather than preforming the a-amino ketimines to be reduced, it is often advantageous to form in situ the more reactive iminium ions from a-aminoketones and primary amines or ammonium salts in the presence of the reducing agent, e.g., sodium cyanoborohydride. Use of this procedure (reductive amination) with the enantiopure a-aminoketone 214 and benzylamine allowed the preparation of the syn diamines 215 with high yields and (almost) complete diastereoselectivities [100] (Scheme 32). Then, the primary diamines 216 were obtained by routine N-debenzylation. Similarly, the diamine 217 was prepared using ammonium acetate. In... 

Derivatized polyethers such as polyether sulfate have been investigated for both positive- and negative-ion calibration [11]. Although poly ether sulfates are not commercially available, they are easily synthesized. Lauryl sulfate ethoxy-lates were also used as calibrants for negative-ion ESI. Polyether amines and quaternary ammonium salts were used as positive-ion calibration solutions [11]. These commercially available compounds do not exhibit significant sodium or potassium adducts, and they are more easily flushed out of the mass spectrometer ion source than are nonderivatized polyethers. In addition, doubly charged poly ether diamines can produce reference peaks at low m/z values. 

In the simplest case, reaction of a primary monoamine via a two-fold Michael reaction with acrylonitrile (bis-cyanoethylation) led to the dinitrile (Fig. 1.1). Subsequent reduction of the two nitrile functions - by hydrogenation with sodium borohydride in the presence of cobalt(II) ions - afforded the corresponding terminal diamine. Repetition (iteration) of this synthetic sequence, consisting in Michael addition followed by reduction, provided the first - structurally variable - access to regularly branched, many-armed molecules. 

The effect of a complex-forming agent on the cation-exchange processes of montmorillonite is well demonstrated in calcium-montmorillonite, manganese(II) ion, and the sodium salt of the ethylene diamine tetraacetic acid (EDTA) system (K6nya and Nagy 1998 Konya et al. 1998). The reactions are illustrated in Figure 2.9. 

Tetra sodium salt of ethylene diamine tetracetic acid. 40% aqueous solution. Sequesters metal ions as described for TETRALON ACID above and would be chosen for economy and where liquids are suitable. 

Recently, a new type of reaction - that is, aerobic oxidative cyanation of tertiary amines - was discovered. In this reaction, oxidation with molecular oxygen in place of peroxides, in addition to direct carbon-carbon bond formation by trapping of the iminium ion intermediates with a carbon nucleophile under oxidative conditions, is accomplished simultaneously. The ruthenium-catalyzed oxidation of tertiary amines with molecular oxygen (1 atom) in the presence of sodium cyanide gives the corresponding a-aminonitriles (Eq. 3.74) [132], which are useful for synthesis of a-amino acids and 1,2-diamines. 

Chelating agents. The role of the chelating agents is to block the polyvalent ions and to make them undetectable and ineffective. Sodium salts of ethylene diamine tetraacetic acid (EDTA) and of nitrilo triacetic acid (NTA) are members of the group of chelating agents and their use has increased in the last few years. 

For the hydrodimerization of butadiene with water, attempts have been made to increase the reactivity by adding acidic solids [4], salts such as sodium phosphate [5], emulsifiers [6], carbon dioxide [7], or the like, with no satisfactory results. In particular, the reaction rate increases under a carbon dioxide pressure, but carbonate ions, not carbon dioxide itself, are considered to play an important role in this effect. It is known that the carbonate ion concentration in water is very low even under a carbon dioxide pressure. If the carbonate ion is the true reactant, the reaction rate should increase with the carbonate ion concentration. Since inorganic carbonates show almost no effect, the addition of various tertiary amines having no active hydrogen, under a carbon dioxide pressure was tested [8]. Diamines and bifunctional amines inhibited the reaction. The reaction rate increased only in the presence of a monoamine having a p/f of at least 7, almost linearly with its concentration (Figure 3). 

Alternatively, QAE-Sephadex A-50 may be rapidly equilibrated with ethylene-diamine (2.88 g/l)-acetic acid (73 ml of 1 M/1) buffer, pH 7.0, in a fume hood. The rabbit or human serum is diluted with an equal volume of the same buffer, and applied to the column. IgG passes through while other proteins are adsorbed. Contaminants may be desorbed with a buffer consisting of 435 ml 600 mM acetic acid and 130 ml 600 mM sodium acetate per litre (pH 4.0). Volume change of the ion-exchanger is avoided since the ionic strength of the buffer is maintained at 0.1 (Tijssen and Kurstak, 1974). The yield is 70-85% for the various sera with at least 90% purity if overloading is avoided. Not more than half the column volume of diluted serum should be applied. 

It is prepared by the reaction of sodium or potassium thiocyanate with chloroformic acid methyl ester, and the intermediate product reacts with o-phenylene diamine to form the thiophanate. Thiophanate-methyl is a colourless, crystalline compound hardly soluble in water. It forms unstable salts and complexes with bivalent ions in alkaline solutions. The range of action of each thioallophanic acid derivative is identical with that of the benzimidazole derivative into which it is converted in the plant. Thiophanate-methyl has both a preventive and a curative action. 

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