Uptake of radiocesium and alkali metals by mushrooms

Various mushrooms and soils were analyzed for alkali metals and for radiocesium. The obtained concentration factors of the nonradioactive Cs for mushrooms are not significantly different from that for vascular plants, whereas in the case of radiocesium the values found were orders of magnitude higher. The different behaviour of natural and radioactive cesium may be due to their disequilibrium in the ecosystems. The irradiation of man due to ingestion of contaminated mushrooms cannot cause a significant health risk.     

On the mechanism of the formation of ozonides of the alkali metals

Conclusions A mechanism of the formation of ozonides of alkali metals was proposed on the basis of data obtained in an investigation of the reaction of oxygen-labeled KOH with ozone, the reaction of KOH with atomic oxygen, and the reaction of KOH with ozone; this mechanism is based upon: the catalytic decomposition of ozone on the surface of the solid alkalies into molecular and atomic oxygen, the interaction of the latter with the hydroxide, forming a superperoxide, and an interaction of the superperoxide with ozone, forming the ozonide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1183–1187, June, 1967.     

Reduction of 4-hydroxy-3, 5-dialkylbenzaldehydes with complex hydrides of alkali metals

Conclusions A study was made of the reduction of seven 4-hydroxy-3,5-dialkylbenzaldehydes with aluminum lithium hydride and sodium borohydride.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1311–1313, June, 1971.     

New fluorochromatouranylates of alkali metals: Synthesis and structure

Four new fluorochromatouranylates, namely, K[UO₂(CrO₄)F] · 1.5H₂O (I), Rb[UO₂(CrO₄)F] · 1.5H₂O (II), Rb[UO₂(CrO₄)F] · 0.5H₂O (III), and Cs[UO₂(CrO₄)F] · 0.5H₂O (IV), have been synthesized, and their crystallographic characteristics have been determined. All the compounds crystallize in monoclinic system, space group P2₁/c, with the unit cell parameters a = 13.1744(5) Å, b = 9.4598(3) Å, c = 13.0710(4) Å, β = 103.746(1)°, Z = 4, R = 0.0235 (I); a = 13.5902(7) Å, b = 9.5022(4) Å, c = 13.2271(6) Å, β = 102.914(2)°, Z = 4, R = 0.0247 (II); a = 24.7724(8) Å, b = 12.6671(4) Å, c = 9.4464(3) Å, β = 97.661(1)°, Z = 8, R = 0.0448 (III); a = 25.725(1) Å, b = 12.8261(5) Å, c = 9.4929(4) β = 97.208(1)°, Z = 8 (IV). The pairs of compounds I and II and compounds III and IV are isostructural. Crystals of compounds I–III have been subjected to complete X-ray diffraction study. It has been established that the structures of compounds I–III are built of [UO₂(CrO₄)F] _n ^n? layers, which are parallel to the (100) plane and linked into a framework by alkali-metal cations located between layers, together with water molecules. The effect of topological and geometric isomerism on the structural features of 34 known uranyl compounds of the AT³M² crystallochemical group, to which the studied compounds I–III also belong, is discussed.     

Determination of alkali metals by laser-induced atomic-ionization in flames

The technique of laser-induced atomic-ionization (AI) in flames has been used for direct determination of Na, K, Rb, and Cs in samples such as water, high-purity alkali metals and their salts and polymeric organosilicon compounds. Different procedures for sample introduction into the flame were studied: (a) the sample was placed onto the cathode of the detector (this gave limits of detection for Na and Cs of 4 x 10(-16) and 2 x 10(-15) g, respectively), (b) electrothermal vaporization and (c) aspiration of the sample into the flame. To reduce the interference of SiO(2) in the AI determination of K in polymeric organosilicon compounds (at the level of 10(-3)-10(-5)%), a procedure involved additional electrical heating of the FID cathode was developed. The efficiency of certain schemes for the laser stepwise and two-photon excitation of atoms was compared for determination of Na.     

The aromaticity of pyracylene: an experimental and computational study of the energetics of the hydrogenation of acenaphthylene and pyracylene

In this work, the aromaticity of pyracylene (2) was investigated from an energetic point of view. The standard enthalpy of hydrogenation of acenaphthylene (1) to acenaphthene (3) at 298.15 K was determined to be minus sign(114.5 +/- 4.2) kJ x mol(-1) in toluene solution and minus sign(107.9 +/- 4.2) kJ x mol(-1) in the gas phase, by combining results of combustion and reaction-solution calorimetry. A direct calorimetric measurement of the standard enthalpy of hydrogenation of pyracylene (2) to pyracene (4) in toluene at 298.15 K gave -(249.9 plus minus 4.6) kJ x mol(-1). The corresponding enthalpy of hydrogenation in the gas phase, computed from the Delta(f)H(o)m(cr) and DeltaH(o)m(sub) values obtained in this work for 2 and 4, was -(236.0 +/- 7.0) kJ x mol(-1). Molecular mechanics calculations (MM3) led to Delta(hyd)H(o)m(1,g) = -110.9 kJ x mol(-1) and Delta(hyd)H(o)m(2,g) = -249.3 kJ x mol(-1) at 298.15 K. Density functional theory calculations [B3LYP/6-311+G(3d,2p)//B3LYP/6-31G(d)] provided Delta(hyd)H(o)m(2,g) = -(244.6 +/- 8.9) kJ x mol(-1) at 298.15 K. The results are put in perspective with discussions concerning the "aromaticity" of pyracylene. It is concluded that, on energetic grounds, pyracylene is a borderline case in terms of aromaticity/antiaromaticity character.     

Separation of alkali metals by extraction chromatography with dipicrylamine and nitrobenzene

An extraction chromatographic method to separate rubidium and cesium using a nitrobenzene solution of ammonium dipicrylaminate has been developed. The procedure is used in connection with a concentration-dependent radioisotope distribution method for determining traces of cesium in rubidium salts. A frontal chromatographic enrichment method to eliminate excess sodium, lithium and calcium salts has been worked out. The results are compared with the conclusions drawn from the extraction mechanism and with other separation procedures. Part VIII of the series “The method of concentration-dependent distribution in the quantitative use of radioisotopes”; for Part VII, seeChem. Listy, 61 (1967) 440.     

Determination of alkali metals in high-temperature Bi-containing superconductors by ICP-AES

Lowering of the detection limits of the alkali elements in Bi-containing superconductors was achieved by optimization of the carrier gas flow rate in ICP-AES. The contents of the alkali metals in the final superconducting products, obtained on the basis of the Li, Na, K, Rb and Cs doped Bi-containing materials, were investigated. A significant decrease of their concentrations after the synthesis was found. The limits of detection with respect to the dissolved solid were as follows: 1.0×10^–4% Li, 1.0×10^–3% Na, 7.7×10^–4% K and 9.7×10^–4% Rb. The relative standard deviation was not more than 0.6 % for Li, 1% for Na and 2% for K and Rb.     

Phase formation, crystal structure, and electrical conductivity of triple phosphates of alkali metals and titanium

For triple phosphates of composition A′_0.5A_0.5 Ti₂(PO₄)₃ (A?A′=Li?Na, Na?K, K?Rb), phase formation is studied, the crystal structure is refined, and the electrical conductivity is measured. The compounds are classified with the NaZr₂(PO₄)₃ structure type (NZP, space group R $\bar 3$ c). The phosphate frameworks are built of TiO₆ octahedra and PO₄ tetrahedra. Extraframework positions M1 are fully occupied by randomly distributed alkali cations. Positions M2 are vacant. Correlations are found between the structural distortion and electrical conductivity of the phosphates, on one hand, and the alkali cation size, on the other.     

Chromatographic separation of some alkali metals

The chromatography of the alkali metals is described using 5% 15 N NH₃ in methanol as solvent and bromophcnol blue to identify the spots. Interfering elements have been studied. The method gives a rapid and more positive method of separation and identification than previously possible.     

Reduction of methylene blue and related dyes by gamma-irradiated alkali halides

A spectrophotometric study is reported of the reduction of some dyes having the methylene blue structure used in bacteriological staining. The reduction is effected by the species liberated during the dissolution of -irradiated sodium chloride, in the same way as by direct low -dose. The G values for the two modes of the reduction are compared and the effects of radical scavengers on the reactions are studied. Results are found to be similar to the chemically and biologically induced reductions. The dyes studied include besides Methylene Blue, Janus Green B and Nile Blue sulfate.