Potassium-Ammonia

Potassium Ammonia Methyl iodide Maleic acid... 

The volume expansions of alkali metals in liquid ammonia are discussed in the light of the current available data. Special emphasis is made of the anomalous volume minimum found with sodium-ammonia and potassium-ammonia solutions. Recent studies of potassium in ammonia at —34° C. were found to exhibit a large minimum in the volume expansion, AV, vs. concentration curve. The results of these findings were compared with the previous results of potassium in ammonia at —45° C. The volume minimum was found to be temperature dependent in that the depth of the minimum increased and shifted to higher concentrations with increasing temperature. No temperature effect was observed on either side of the minimum. These findings are discussed in light of the Arnold and Patterson and Symons models for metal-ammonia solutions. 

Let us again review the previous findings for the volume expansion of sodium and potassium in liquid ammonia. Filbert (8) reported a volume minimum for sodium in ammonia at —46° C. at approximately 0.03N. Orgell (21) confirmed the existence of this minimum for sodium in ammonia at —45° C. and extended his study to potassium in ammonia at the same temperature. Potassium-ammonia solutions were found to exhibit a minimum at O.OliV which was quite sharp and not nearly as broad as the minimum for sodium at —45° C. More recently, Brendley has investigated the volume expansion of potassium in ammonia at —34° C. Once again a pronounced minimum was found. The potassium data at —45° C. and —34° C. showed differences in the position and... 

Fig. 4. (continued) (c) The optical properties of sodium-ammonia and potassium-ammonia solutions (208 K), and variation of the near-IR band maxima with concentration. [Data of Douthit and Dye (49), Gold and Jolly (84), Koehler and Lagowski (107), Rubinstein etal.(144), and Quinn and Lagowski (142), as given by Harris (88).] (d) ESR spin-spin relaxation time TSe at 238 K. [Data from Chan etal. (V, Ref. 31), Essigd, Ref. 72), and Hutchison and Pastor (O, Ref. 98), as given in Schindewolf (148).]... 

Fig. 5. Electron spin pairing in metal-ammonia solutions at 25°C (298 K), 0°C (273 K), and -33°C (240 K). Paramagnetic spin concentrations for sodium-ammonia and potassium-ammonia solutions. [Experimental data from Refs. 47, 76, 98, 114,115, and 159. Adapted from Harris (88). Used with permission.] The solid line indicates the expected spin-pairing behavior for noninteracting electrons (88).

Since the first preparation of potassium-ammonia solution (Sir Humphrey Davy, in 1808) alkali metal-ammonia solutions have been at the centre of much theoretical and experimental interest. Novel properties include low density, high electrical conductivity, liquid-liquid phase separation, and a concentration driven metal-nonmetal transition [35]. 

The structure of Li and K ammonia solution has been recently studied by neutron diffraction experiments [36]. The results show, for saturated lithium-ammonia solutions, that the cation is tetrahedrally solvated by ammonia molecules. On the other hand, from the data of the microscopic structure of potassium-ammonia solutions, the potassium is found to be octahedrally coordinated with ammonia molecules. The Li+ is a structure making ion and K+ is a structure breaking ion in alkali metal-ammonia solutions [37, 38]. 

Overberger, Yuki, and Urukawa (50) studied the polymerization of methacrylonitrile in the potassium-liquid ammonia system. The results obtained with potassium amide-ammonia were the same as with potassium-ammonia. Isobutyronitrile was detected in the reaction products, indicating that potassium amide was initiating the quantitative polymerization as in the styrene-potassium-ammonia system (93). It was also found that potassium hydroxide initiated polymerization of methacrylonitrile in liquid ammonia, but at a slower rate than potassium or potassium amide. 

Alkali and alkaline earth metals powdered aluminum or magnesium, calcium, lithium, sodium, potassium Ammonia (anhydrous), bromine... 

Phthalimide-N-sulfenyl chloride, 375 Phthaloylamino acids, 212 Phthaloyl-L-valine, 212 Phytuberin, 197 Phytyl chloride, 499, 500 Picrotoxinin, 265, 430 Pictei-Spengler cyclization, 308 Pinacol-typc reduction, 513 -Pinene, 346, 367 Piperidine acetate, 318 Piperidinium acetate, 375-376 Polonovski reaction, 484 Polyaminolactams, 378-379 Polycyclic phenols, 102 Polyene cyclization, 291-292 Polyethylene glycols, 360, 376 Polyketides, 302 Polyphosphate ester, 376-377 Polyprenylation, 499-500 Potassium-Ammonia, 273, 377 Potassium-t-Butylamine-18-Crown-6, 377-378... 

A powerful oxidizer. Explosive reaction with acetaldehyde, acetic acid + heat, acetic anhydride + heat, benzaldehyde, benzene, benzylthylaniUne, butyraldehyde, 1,3-dimethylhexahydropyrimidone, diethyl ether, ethylacetate, isopropylacetate, methyl dioxane, pelargonic acid, pentyl acetate, phosphoms + heat, propionaldehyde, and other organic materials or solvents. Forms a friction- and heat-sensitive explosive mixture with potassium hexacyanoferrate. Ignites on contact with alcohols, acetic anhydride + tetrahydronaphthalene, acetone, butanol, chromium(II) sulfide, cyclohexanol, dimethyl formamide, ethanol, ethylene glycol, methanol, 2-propanol, pyridine. Violent reaction with acetic anhydride + 3-methylphenol (above 75°C), acetylene, bromine pentafluoride, glycerol, hexamethylphosphoramide, peroxyformic acid, selenium, sodium amide. Incandescent reaction with alkali metals (e.g., sodium, potassium), ammonia, arsenic, butyric acid (above 100°C), chlorine trifluoride, hydrogen sulfide + heat, sodium + heat, and sulfur. Incompatible with N,N-dimethylformamide. 

The base isopilocereine, obtained in small yield by the potassium-ammonia cleavage of pilocereine 111) and 0-methylpilocereine (113), was shown by degradation and synthesis to have the dimeric formula CLVII (114-119) assigned previously to pilocereine. 

Bicyclo[6,l,0]nona-2,4,6-triene reacts with 3,6-diphenyl-sym-tetrazine to give the cyclononatriene (71). Methylated cyclononatrienyl anions have been generated by potassium-ammonia reduction of bicyclo[6,l,0]nona-2,4,6-trienes, and their... 

Wasse JC, Hayama S, Skipper NT et al (2000) The stmcture of saturated lithium- and potassium-ammonia solutions as studied by neutron diffraction. J ChemPhys 112 7147-7151... 

Ruff andZedner have found similar phase separations for lithium-and potassium-ammonia solutions. Kraus and Johnson have confirmed the occurrence of phase separation for lithium-ammonia solution. Hodgins has performed careful vapor pressure and conductance measurements in cesium-ammonia solutions in the concentration range 0.04 M to 7Af but did not find any evidence for phase separation. Kraus has found from vapor pressure measurements that a liquid-liquid phase separation occurs below — 32.5° C and above a concentration of about 2M 5 mole per cent). Also the curve for vapor pressure as a function of concentration indicates the formation of the solid compound Ca(NHj)g at a temperature of — 32.5° C and concentration larger than 4 Af. 

Figure 2. Plot of conductance as a function of concentration for sodium-and potassium-ammonia solutions (Reference 40).

As regards the temperature-dependence of the temperature coefficient Kraus has found that for sodium- and potassium-ammonia solutions in the region 0.13M to saturation, the differential temperature coefficient is almost independent of temperature in the temperature range — 33° C to — 45° C. In more dilute solutions (0.04—0.004Af) also, the temperature coefficient is found to be independent of concentration and temperature in the temperature range — 30° C to — 48°C for potassium and — 30° C to — 70 C for potassium. Its value is 2 ]>er cent for sodium- and 2.9 per cent for potassium-ammonia solutions. 

Recent studies of thermoelectric effects in sodium- and potassium-ammonia solutions provide information about structure of metal-ammonia solutions and the mechanism of charge transport in them... 

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