Liquid ammonia thiocyanate solutions

The thiocyanate ion SCN forms an intensely red-coloured complex (most simply represented as [Fe(SCN)(H20)5] ) which is a test for iron(III). However, unlike cobalt(III), iron(lll) does not form stable hexammines in aqueous solution, although salts containing the ion [FefNHj) ] can be obtained by dissolving anhydrous iron(III) salts in liquid ammonia. 

A solution or suspension of 0.22 mol of the lithium or sodium alkynylide in 300 ml of liquid ammonia is prepared as described on p. 20. The disulfide, thiosulfonate or thiocyanate (0.20 mol, diluted with 50 ml of Et20, is added dropwise over 10 min with efficient stirring. In many cases a rather thick suspension is formed an additional volume of-100 ml of liquid... 

This reaction can also be run in a continuous fashion. In the initial reactor, agitation is needed until the carbon disulfide liquid phase reacts fully. The solution can then be vented to a tower where ammonia and hydrogen sulfide are stripped countercurrendy by a flow of steam from boiling ammonium thiocyanate solution. Ammonium sulfide solution is made as a by-product. The stripped ammonium thiocyanate solution is normally boiled to a strength of 55—60 wt %, and much of it is sold at this concentration. The balance is concentrated and cooled to produce crystals, which are removed by centrifugation. 

The trichloride dissolves in liquid cyanogen.1 It combines with cyanogen bromide when a mixture of the two is slowly heated in an autoclave to 180° C., followed by cooling and keeping at 120° C. for one hour 2 the product, of composition AsCls.2BrCN, decomposes on heating above 190° C. Arsenic trichloride reacts with potassium thiocyanate solution,3 the latter being decomposed with liberation of ammonia, but no precipitate is produced, whereas both tin and antimony are precipitated as hydroxides under similar conditions the reaction with excess of potassium thiocyanate may be used to effect a quantitative separation of these two metals from arsenic. 

Fusion of ammonium thiocyanate,6,6 either alone or in the presence of heavy metal salts, at 180°C., gives guanidine thiocyanate. This procedure has been modified by heating lead nitrate with a solution of ammonium thiocyanate in liquid ammonia at 120°.7 Lead sulfide is formed, and guanidine nitrate recovered. Other methods of formation involve the hydrolysis of dicyandiamide8-10 and the nitridation11 of methyl amine by means of ammonium azide in liquid ammonia. 

Nickelamide, Ni(NH 2)2, is precipitated as a red, flocculent mass when a solution of nickel thiocyanate in liquid ammonia is treated with... 

White Cd(CN)2 is sparingly soluble in water, except in the presence of CN ions, owing to the formation of soluble anionic complexes. On heating it darkens and decomposes at about 200 °C. Cd(CN)2, like Zn(CN)2, has a cubic anti-cuprite structure. Colorless cadmium thiocyanate is sparingly soluble in water, ethanol, and liquid ammonia. In the solid, Cd + is surrounded by an N2S4 octahedron. Cadmium thiocyanate polymers exhibit highly anisotropic physical properties. Yellow Cd(N3)2 is prepared by mixing solutions of Cd(N03)2 and NaNs. The crystals are orthorhombic and decompose with detonation when heated. Cadmium pseudohalides (see Pseudohalide) may be prepared by metathesis (equation 3). 

The [In(NH3)6] " cation has been identified in liquid ammonia solution, but attempts to prepare the perchlorate salt were unsuccessful. Mixed complexes such as [In(NH3)sBr] have been postulated in liquid ammonia, but this has not been confirmed preparatively. Ethylenediamine yields the salt [Inen3] (004)3 on reaction with In(004)3(aq) in ethanol, and the analogous nitrate and thiocyanate salts have also been prepared. 

Cellulose in liquid ammonia/ammonium thiocyanate solutions... 

Gas-activated Batteries. The gas-activated batteries were attractive because their activation was potentially simpler and more positive than liquid or heat activation. The ammonia vapor-activated (AVA) battery was representative of a system in which the gas served to form the electrolyte. (Solids such as ammonium thiocyanate will absorb ammonia rapidly to form electrolyte solutions of high conductivity.) In practice, ammonia vapor activation was found to be slow and nonuniform, and the development of the ammonia battery was directed to liquid ammonia activation which, in turn, was found to be inferior to newer developments. The chlorine-depolarized zinc/chlorine battery was representative of the gas depolarizer system. This battery used a zinc anode, a salt electrolyte, and chlorine, which was introduced into the cell, at the time of use, as the active cathode material. The battery was designed for very high rate discharge ranging from 1 to 5 min, but its poor shelf life while inactivated limited further development and use. 

Introduce the benzoic acid residue as the sodium salt into a boiling-tube and heat in a beaker of boiling brine until the liquid is driven off and all drops of condensation water have disappeared. Cool, add 0 1 g of potassium nitrate and 1 ml of concentrated sulphuric acid. Place the tube in boiling water for twenty minutes. Cool and add 2 ml of water. Hold the tube under running water and add carefully 10 ml of 15 per cent ammonia solution followed by 2 ml of a 2 per cent hydroxylamine hydrochloride solution. Mix well and place in a beaker of water at 65° for five to six minutes. Cool and match the colour with that developed by mixing the amounts of iron ammonium alum and potassium thiocyanate solution given below for varying quantities of benzoic acid. 

Still due to the strong cohesion of this material, cellulose is insoluble in most organic solvents. Only some highly polar mixtures such as A, A -dimethylacetamide/ lithium chloride, AT-methylmorpholine/water, Cu(OH)2/ammonia, trifiuoroacetic acid/alkyl chloride, calcium thiocyanate/water, and ammonium thiocyanate/liquid ammonia are solvents of cellulose. In spite of the potential applications of such solutions, they are exploited relatively little due to their high cost. 

Chitin is a white, amorphous solid, insoluble in water, dilute acids, dilute and concentrated alkali, and organic solvents. It readily dissolves in concentrated hydrochloric, sulfuric, nitric, and phosphoric acids, in anhydrous formic acid, with difficulty in liquid ammonia, but not in Schweizer s reagent. Hot, concentrated solutions of neutral salts, like lithium and calcium thiocyanate, dissolve chitin, which can then be reprecipitated by dilution with alcohol or acetone, without apparent degradation. 

Carbon disulphide interacts with dry ammonia, but the reaction has not yet been fully investigated the gas is slowly absorbed and a dark brown liquid results, which probably contains ammonium thiocarbonate and thiocyanate.6 An alcohol solution of ammonia readily dissolves carbon disulphide,7 the foregoing products being formed (see also p. 264).8... 

Huber and Van der Wielen determine the volatile oil (thiocyanate) in mustard seeds as follows. Their experiments were directed towards determining to what extent the time of maceration of the crushed seeds in water influences the result. Five gram samples of the mustard were macerated for 1, 2, 4, 18, and 20 hours respectively, with 100 c.c. of water, after which were added 20 c.c. of alcohol and 2 c.c. of olive oil. Of the mixture about 50 c.c. were distilled into a 100 c.c. measure containing 10 c.c. of ammonia, taking care that the delivery tube was immersed in the ammonia. After adding 20 c.c. of deci-normal silver nitrate solution the whole was heated over a water-bath until the silver sulphide had aggregated and the liquid was clear. The liquid was then cooled and made up with water to 100 c.c., the excess of silver nitrate was determined by titration with deci-normal ammonium thiocyanate, usW iron alum as an indicator. 

Solubilities of ammonia in ionic liquids, l-ethyl-3-methylimidazolium acetate ([EMIm]Ac), l-ethyl-3-methylimidazolium thiocyanate ([EMIm]SCN), l-ethyl-3-methylimidazolium ethylsulfate ([EMImJEtOSOs), and N,N-dimethy- lethanolammonium acetate ([DMEA]Ac) were measured for the first time by A.Yokozeki and M.B. Shiflett [7] in 2007. Six mixture compositions of each binary system were involved from about 30 to 85 mole% of ammonia. Pressure-temperature-composition (P-T-x) data were claimed at isothermal conditions of 283, 298, 323, 348, and 373 K. The observed solubility of ammonia in ionic liquids is very high, and all cases show negative deviations from ideal solution behavior. Experimental P-T-x data were successfully correlated with the equation-of-state (EOS) model [8]. The experimental data and fitting results are shown in Figure 5 8. The opportunity for the absorption cycle application using the ammonia-RTIL system, replacing the traditional ammonia-water system, has been discussed [7]. 

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