Effect of the Λ n interaction on the cross section of the reaction γd → K+Λ n

Taking into account the n interaction, a nonrelativistic graphical technique is used to calculate the differential cross section of the reaction d K⁺ n as a function of photon energy, K⁺-momentum, and angle of emission of the K⁺. The kinematic region in which variation of the n-scattering parameters gives the most noticeable effect is separated out.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 104–106, August, 1978.The author thanks G. M. Radutskii and V. A. Filimonov for many useful discussions.     

Formation and Transformations of Polynuclear Hydroxo- and Oxotrimethylacetate Complexes of Ni(II) and Co(II)

Transformations of polymeric trimethylacetate complexes [M(OH) _n (OOCCMe₃)_{2 – n} ] _m (M = Ni (I) and Co (II)) and clusters Ni₉(₄-OH)₃(₃-OH)₃(-O,O-OOCCMe₃)(-O,O"-OOCCMe₃)₇(₃-O,O,O"-OOCCMe₃)₃(₄-O,O,O",O"-OOCCMe₃)(HOOCCMe₃)₄(III) and Co₆(₃-OH)₂(-OOCCMe₃)₁₀(HOOCCMe₃)₄(VIII), which are formed from Iand IIupon their recrystallization from nonpolar solvents, were studied. It was shown that the action of N-phenyl-o-phenylenediamine (L) on Ior IIIresults, depending on the solvent, in different tetranuclear clusters with the hydroxo bridges. For example, in benzene, the L₂Ni₄(₃-OH)₂(HOOCCMe₃)₄(-OOCCMe₃)₆complex (IX) is formed; its L molecules are coordinated in a monodentate way, whereas in acetonitrile, they chelate to give the {[o-C₆H₄(NH₂)(NHPh)]₂Ni₄(₃-OH)₂(MeCN)₂(OOCCMe₃)₂(-OOCCMe₃)₄} compound (X). Heating of Xin the presence of atmospheric oxygen yields IX, the mononuclear bissemiquinonediimine [o-C₆H₄(NH)(NPh)]₂Ni complex (XI), and water. It was noted that the use of aniline in these reactions affords, independent of the nature of the solvent, only one (NH₂C₆H₅)₂Ni₄(₃-OH)₂(HOOCCMe₃)₄(-OOCCMe₃)₆cluster (VI); in acetonitrile, this cluster is formed as the solvate VI· 2HOOCCMe₃(VIa). When treated with ethanol, Iand IIIgive the Ni₄(EtOH)₆(₃-OH)₂(₂-OOCCMe₃)₄(OOCCMe₃)₂cluster (V), which is structurally close to the known cobalt-containing analog IV. Thermolysis of IVin decalin at 170° causes its dimerization, giving the octanuclear Co₈(₄-O)₂( _n -OOCCMe₃)₁₂complex (VII) with the tetradentate oxo bridges.     

Observation of difluorinated higher fullerene anions by Knudsen cell mass spectrometry and determination of electron affinities of C60F2 and C70F2

Difluorinated higher fullerenes have been studied by Knudsen cell mass spectrometry. Thermal negative ions C_nF₂⁻ (n=60, 70, 72, 74, 76 and 78) were produced inside the effusion cell as well as the neutral molecules C₆₀F₂ and C₇₀F₂. From the equilibrium constants for the electron exchange reactions between difluorinated fullerenes and their parents electron affinity values were derived for C₆₀F₂ (2.74 eV) and C₇₀F₂ (2.80 eV).     

Unusual condensation of propargylamine. Generation of the 1,3-di(propargylimino)propane anion coordinated to the cobalt(iii) atom

The reaction of propargylamine with the hexanuclear complex Co^II ₆(₃-OH)₂(OOCCMe₃)₁₀(HOOCCMe₃)₄ or the polymer [Co(OH)_n(OOCCMe₃)_2–n]_x under an argon atmosphere afforded the unstable paramagnetic tetramine complex Co^II(OOCCMe₃)₂(H₂NCH₂CCH)₄ (1). In air, if an excess of propargylamine is present, the latter complex is transformed into the complex Co^III(OOCCMe₃)₂(NH₂CH₂CCH)₂[²-N,N"-(HCCCH₂N=CHCHCH=N—CH₂CCH)] (2) containing a new ligand, viz., the 1,3-di(propargylimino)propane anion, which is a formal analog of the acetylacetonate anion. In contrast to propargylamine, 1,3-diaminopropane reacted with the Co^II trimethylacetate clusters in air to produce the cationic complex [Co^III{1,3-(NH₂)₂(CH₂)₃}₂(OOCCMe₃)₂]⁺OOCCMe₃ ^– (3) without entering into condensation reactions. The structures of the resulting complexes were determined by X-ray diffraction analysis.     

Reactions of N-alkylazinium cations. Reaction of acridinium salts with enamines

The reaction pyridinium N-methylazinium salts and their benzo analogs — quinolinium, isoquinolinium, and acridinium ions — with enamines was investigated. Acridanyl-substituted enamines, their iminium salts, and the corresponding ketones were obtained by reaction of the N-methylacridinium salts with the enamines in dimethyl sulfoxide at room temperature. The quinolinium and isoquinolinium salts have lower activities; the N-methylpyridinium cation does not react at all under the indicated conditions.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 666–669, May, 1979.     

Cellulose conversion to polyols in subcritical water

Subcritical water is shown to be an efficient medium for the cellulose conversion process to produce polyols. A novel type of Ru-containing hyper-crosslinked polystyrene (HPS)-immobilized catalyst is suggested. Application of the catalyst containing 1% Ru can achieve a total yield of sorbitol and mannitol of about 50%; that is comparable with the results obtained in the presence of more complex and, therefore, more expensive catalytic systems. The influence of both the process conditions and the catalyst properties on the target product yield is studied. The hydrolytic hydrogenation of cellulose in subcritical water using Ru-containing HPS-immobilized catalysts can become a base for novel technologies of cellulose biomass conversion and production of raw materials for chemical synthesis and industrial production of second generation biofuels.     

Modelling of sensitivity of plasmon sensory elements based on silver nanoparticles obtained by laser evaporation and ablation

A comparison of the sensitivity of the spectral position of plasmon resonance calculated by numerical methods to a change in the refractive index of the environment for ellipsoidal and spherical silver nanoparticles with a dielectric shell synthesized by laser ablation has been performed. It has been shown that sensitivity is higher for nanoparticles with the shape of a prolate ellipsoid than for spherical nanoparticles. The modeling has shown that the optimal thickness of the dielectric shell should be 10–12 nm and its refractive index should be 1.6. With this, a sensitivity of the plasmon sensor of 32 nm/RIU (RIU is refractive index unit) may be provided.     

A prototype of a high-voltage platform for the KRION ion source

A high-voltage platform that has been developed for the KRION ion source is described. The platform design concept is explained. The calculations that have been performed of the influence of the design and materials on the source magnetic field make it possible to define a range of materials suitable for manufacturing the platform. The major components of the high-voltage platform, such as a high-voltage power supplier, and decoupling insulators of the high-voltage power source, and the main and supplementary platforms, are chosen and described. It is determined that, to exclude electric breakdowns and corona discharges, one should use an electrically shielded channel with a cryocooler and power supplies for the KRION-source coupling cables.