Ammonia electropositive

Reactions with electropositive metals. Ammonia gas reacts with strongly electropositive metals to form the amide, for example... 

Arsine is formed when any inorganic arsenic-bearing material is brought in contact with zinc and sulfuric acid. The arsenides of the electropositive metals are decomposed with the formation of arsine by water or acid. Calcium arsenide [12255-53-7] Ca2As2, treated with water gives a 14% yield of arsine. Better yields (60—90%) are obtained by decomposing a solution of sodium arsenide [12044-25-6] Na As, in Hquid ammonia with ammonium bromide (14,15). Arsine may be accidentally formed by the reaction of arsenic impurities in commercial acids stored in metal tanks, so that a test should be made for... 

Reaction of acetylene with electropositive metals in liquid ammonia. 

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. 

Fullerenes can be easily chemically reduced by the reaction with electropositive metals [1, 97-99], for example, alkali- and alkaline earth metals. The anions Cjq"" (n = 1-5) can be generated in solution by titrating a suspension of in liquid ammonia with a solution of Rb in liquid ammonia [100], whereupon the resulting anions dissolve. Monitoring of this titration is possible by detecting the characteristic NIR absorption of each anion by UV/Vis/NIR spectroscopy. The solubility of the alkali metal fullerides in the polar solvent NHj demonstrates their salt character. 

Kraus has shown that many of these compounds of the alkali metals with the less electropositive metals (some of which are soluble in liquid ammonia) possess many of the properties of typical salts. He calls these salts of homoatomic anions. It should be noted that in handbooks or indexes, these compounds are to be found... 

Only amides of the more electropositive metals can be prepared by the direct interaction of ammonia or a primary or secondary amine with the metal. Hence, the molten alkali metals will react with gaseous ammonia liberating hydrogen (e.g. equation 1).M... 

Electropositive leaving groups such as phosphonium and ammonium ions [ROP+(Ph)3, RN+R3] can have favourable dipolar interactions in the transition state and therefore reaction rates can be enhanoed. Similarly, the use of a neutral nucleophile such as ammonia or hydrazine will reverse the polarity of the forming bond in the transition state, giving rise to favourable polar interactions with neighbouring electronegative substituents. 

Liquid ammonia has lower reactivity than H20 toward electropositive metals, which may dissolve, giving blue solutions (Section 3-3). 

IR studies have shown that strongly electropositive metals form salts with nitroimidazoles in which the negative charge is largely associated with the nitro function (Section 4.06.3.7). Nitroimidazoles dissolve in aqueous solutions of alkali metal hydroxides, carbonates or ammonia to form yellow solutions containing the nitroimidazole anion (B-76MI40701). 

Sodium metal is a good source of free electrons. It is so electropositive, it readily gives up one electron to form the cation. At room temperature, sodium reacts with ammonia to form sodamide, NaNH2, and hydrogen in a simple inorganic redox reaction. However, if the temperature of the... 

Amides and imides. These salts, formed only by the more electropositive metals, contain respectively the NHJ and NH " ions. The alkali, alkaline-earth, and zinc amides are colourless crystalline compounds formed directly by the action of ammonia on the molten metal or in solution in liquid ammonia. A solution of NaNH2 in liquid ammonia is a good conductor of electricity, indicating that the salt is ionized in this solvent. 

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