Cyclic-type cohomology of strict inductive limits of Fréchet algebras

We present methods for the computation of the Hochschild and cyclic-type continuous homology and cohomology of some locally convex strict inductive limits of Fréchet algebras A_m. In the pure algebraic case it is known that, for the cyclic homology of A, for all n?0 [Cyclic Homology, Springer, Berlin, 1992, E.2.1.1]. We show that, for a locally convex strict inductive system of Fréchet algebras such that

0→A_m→A_m+1→A_m+1/A_m→0     

Structural study of bismuth complexes with diethylenetriaminepentaacetic acid in aqueous solutions

Bismuth complexes with diethylenetriaminepentaacetic acid were examined in aqueous solutions (pH 4–10) by UV, IR, and NMR spectroscopy. In aqueous solutions, the polydentate ligand is coordinated to bismuth through three N atoms and five O atoms.     

Adsorption modification of solid surfaces with aqueous solutions of fullerene C60 derivatives containing maleimide and dipeptide addends

The regularities of the adsorption modification of different solid surfaces with aqueous solutions of amino-acid derivatives of fullerene C₆₀ (ADF) that contain the maleimide and dipeptide addends were studied by the methods of wetting and Quartz Crystal Microbalance (QCM). It was found that, despite the absence of surface activity at the solution-air interface, ADFs are well adsorbed at the solution-solid interface. On high-energy surfaces with different charges in aqueous media, at neutral pH, the studied ADF act as ionic surfactants with polar groups charged opposite to the solid surface. The modification of polymers with AFD solutions results in the hydrophilization of their surfaces as in the case of classical low-molecular surfactants.     

A practical and efficient green synthesis of β-aminophosphoryl compounds via the aza-Michael reaction in water

Biphasic systems room temperature imidazolium ionic liquid (RTIL)/water or water as a solvent significantly accelerate the addition of amines to vinylphosphoryl compounds hence opening green and effective synthesis of β-aminophosphoryl compounds in excellent yields over short reaction times. The application of water, being the cheapest and most non-toxic solvent, without any catalyst or co-solvent, is more advantageous as it provides a simple isolation procedure for products having high purity (> 95% according to the NMR data) via simple freeze-drying and does not require extraction with organic solvents. The solubility of the starting phosphorus substrate in water does not play crucial role in the reaction as it was demonstrated using water insoluble diphenylvinylphosphine oxide. In contrast to typical procedures, using a reactant ratio (vinylphosphoryl compound: amine) of 2:1 readily resulted in double phosphorylation of primary amines, including polyamines, in water.     

ZnS:Cr and ZnSe:Cr thin‐film waveguide structures as electrically pumped laser media with an impact excitation mechanism

ZnS:Cr and ZnSe:Cr are the focus of studies as media for broadly tunable optically pumped lasers operating in the near‐ and mid‐IR regions. It is of great interest to obtain such lasers electrically pumped. The effective electrical excitation of Cr²⁺ ions was demonstrated only in the case of the impact mechanism for thin‐film structures with insulator layers between an electroluminescent film and electrodes, which prevent avalanche breakdown at high electric field (≥ 1 MV/cm). To obtain lasing, the waveguide electroluminescent structures were used. For the first time, the stimulated emission and the laser oscillation were demonstrated in the ZnS:Cr waveguide structures. Although the lasing is unstable as yet, these results lay the foundations of a new direction in laser physics aimed at creation of electrically pumped lasers by dint of impact excitation. Published results concerning various aspects of ZnS:Cr and ZnSe:Cr thin films and waveguide structures as promising electrically pumped laser media are reviewed. The causes of the instability of the laser oscillation and means of improving their characteristics are also considered.     

Study of catalase electrode for organic peroxides assays

The catalytic activity of immobilized catalase (EC 1.11.1.6) for two model peroxide compounds (dibenzoyl peroxide and 3-chloroperoxibenzoic acid) in a non-aqueous medium was used to prepare an organic-phase enzyme electrode (OPEE). The enzyme was immobilized within a polymeric film on spectrographic graphite. The amperometric signal of the enzyme electrode in substrate solutions was found to be due to the reduction of oxygen generated in the enzyme layer. The electrode response is proportional to peroxide concentrations up to about 40 microM within the potential range from -450 to -650 mV (vs. Ag/AgCl), and the response time is at most 90 s. The enzyme electrode retains about 35% of its initial activity after a 3-week storage at room temperature.     

Study of the catalytic activity of electrochemically reduced forms of phthalocyanines in the reaction of CO2 with epoxides

Catalytic activity of electrochemically reduced forms of mono- and diphthalocyanine complexes of transition and rare-earth elements in the reaction of carbon dioxide with epoxides is considerably higher than that of corresponding neutral forms. The catalytic efficiency depends on the nature of the phthalocyanine complex, the method of the catalyst immobilization, and the electrophilicity of epoxide. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2205–2213, November, 1998.     

Examples of banach algebras over commutativebanach algebras of given homological dimension

We prove that, for every natural number n, there exists a unital semisimple Banach star algebra Aand a closed star subalgebra Bof the centre of A, different from C, such that the global B-homological dimension and the B-homological bidimension of Aare both equal to n. The algebras Aand Bcan be taken to be function algebras.     

Addition of CCl4 to unsaturated compounds catalyzed by M3(CO)12 (M=Fe, Ru, Os)

The addition of CCl₄ to hex-1-ene and to the methyl ester ofN-(trans-cinnamoyl)-l-proline (2) catalyzed by M₃(CO)₁₂ or by the M₃(CO)₁₂+DMF system (M=Fe, Ru, Os) was studied. The use of ruthenium and osmium dodecacarbonyls in combination with DMF increases the yields of adducts CCl₃CH₂CHClC₄H₉ (4) and PhCHClCH(CCl₃)C(O)R′ (3) over those obtained in reactions catalyzed by the same carbonyls without DMF. In addition to adduct3, salts [M(CO₃)Cl₃]⁻[Me₂NH₂]⁺ were isolated from the products of the reaction between CCl₄ and1 in the presence of M₃(CO)₁₂+DMF (M=Ru, Os). These salts do not catalyze this reaction and apparently result from chain termination. Experimental results in favor of a coordination mechanism of the addition of CCl₄ to olefins in the presence of Ru₃(CO)₁₂ and Os₃(CO)₁₂ were obtained. Translated fromIzvestiya Akademii Nauk Seriya Khimicheskaya, No. 6, pp. 1174–1179, June, 1997.