Catalysis by Pd(I) complexes in olefin isomerization and acetylene carbonylation

Carbonyl palladium(I) halide complexes have been tested as catalysts of olefin isomerization and acetylene carbonylation reactions. A new complex Pd(I)-MPdJ₂.2H₂O, where M=Li, Cs has been synthesized. It is shown that Pd(I) complexes are active catalysts in acetylene carbonylation.

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. Pd(1) MPdJ₂·2H₂O, M=Li, Cs. , .

     

Generalized resolvents of linear relations generated by a nonnegative operator function and a differential elliptic-type expression

We study invertible extensions of the minimal relation generated by a nonnegative operator function and a differential elliptic-type expression. We prove that the operators inverse to such extensions are integral operators and describe such integral operators. We obtain a formula for generalized resolvents of the minimal relation.     

The direct resist-free deposition of a lithographic mask from vapor initiated by an electron beam

A dry resist-free process of electron-beam vapor deposition of an undecane precursor (C₁₁H₂₄) mask on SiO₂-on-silicon and copper-on-silicon substrates was studied. The band section was trapezoidal, and the band width at the base was much larger than the diameter of the electron beam and depended on the substrate (it was three or four times larger on copper than on SiO₂). In mask deposition on copper, the mask thickening rate v was found to depend strongly on the scan time τ_sc when scanning was performed along the band. When τ_sc changed from 20 ms to 13 s, v decreased by a factor of 7.4 (beam current 1.0 nA). This was probably caused by significant diffusion delay of precursor transport to the reaction zone during pixel time when τ_sc was 13 s. The ion-beam etching of the substrates through the deposited masks was performed (the SiO₂ substrate was etched with SF₆ ions, and the copper substrate, with Ar ions).     

Critical phenomena as a discriminating factor in the studies of reaction mechanisms

Eleven mechanisms for heterogeneous catalytic ethylene hydrogenation obtained with a computer program MECHEM were examined for possible multiplicity of steady states in an isothermal flow-type well-stirred reactor. Of these eleven mechanisms, four allow the multiplicity of steady states, but the others do not. The multiplicity of steady states is shown to be a strong discriminating factor when considering the hypothetical mechanisms of catalytic reactions.     

Photoluminescence of ZnS:Cu crystals at various concentrations of copper

Doping of ZnS crystals with background impurities and ZnS:Al crystals by various concentrations of copper from a bismuth melt has been carried out. The photoluminescence spectra of the starting ZnS crystals annealed in the bismuth melt and doped by copper have been investigated. Interpretation of the experimental results according to the model in which the associates (Cu _Zn ^′ Cu _i ^● ) are responsible for the B-Cu band (≈460 nm) and the donor—receptor pairs [Cu _i ^● -(Cu _Zn ^′ Cu _i ^● )] are responsible for the G-Cu band (≈505 nm) is given. It is assumed that doping by copper from a bismuth melt is accompanied by the separation of a Cu_xS-type phase. It has been shown that heat treatment of ZnS crystals in the Bi melt does not lead to the appearance of luminescence centers based on Bi_Zn, Bi_S, and Bi_i. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 72, No. 6, pp. 794–798, November–December, 2005.     

Extensions of symmetric relations

Maximal accretive and dissipative extensions of symmetric relations defined by abstract boundary conditions are considered in Hubert space. Under the assumption that the resolvent of some extension has properties such as belonging to the Neumann-Shatten ideal or having given asymptotics of the s-numbers, either sufficient or necessary and sufficient conditions are found for a perturbation of the boundary conditions guaranteeing that the above properties are preserved for the resolvent of the perturbed extension.Translated from Matematicheskie Zametki, Vol. 22, No. 6, pp. 825–834, December, 1977.     

The Synthesis and Properties of New Metal-free and Metallophthalocyanines Containing Four Diloop Macrocyclic Moieties

The synthesis and characterization of new metal-free (9) and metal-containing (Zn, Ni or Cu 10, 11, 12) derivatives of a symmetrically octasubstituted phthalocyanine derived from 21,22-dicyano-2,3,5,6,8,9,11,12,15,17,18,25,26,28-tetradecahydro[1,4,7,12] benzodioxadithiacyclotetradeceno[6,7-b][1,4,7,10,13]benzopentaoxacyclopentadecene (7), which was synthesized in a multi-step reaction sequence, have been described. The novel compouds have been characterized by a combination of elemental analysis, ¹H and ¹³C NMR, IR, UV–vis and MS spectral data.