Heterogeneous phase transfer catalysts 1. Synthesis and catalytic properties of polymeric crown-ethers on inorganic supports

A number of new heterogeneous phase transfer catalysts based on polymeric dibenzo-crown-ethers supported on the carbonaceous material Sibunite, ultrafine diamonds, or silica gel are synthesized. The activity of several of the catalysts for the reaction of 1-bromooctane with KI is higher than that of previously known analogs. The catalytic effect depends on the support, linker, and solvent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1257–1262. June. 1990.     

Novel laccase redox mediators

The screening of potential redox mediators for laccase was performed using homogeneous enzyme preparations from Coriolus hirsutus and Coriolus zonatus. It was discovered that derivatives of 1-phenyl-3-methyl-pyrazolones were efficient substrates for the laccases. The characterization of two representatives of the 1-phenyl-pyrazolone class, sodium 1-phenyl-3-methyl-4-methylamino-pyrazolone-5-N(4)-methanesulfonate and 1-(3′-sulfophenyl)-3-methylpyrazolone-5, in the reaction catalyzed by laccase was carried out using spectral, electrochemical, and enzyme kinetics methods. The kinetic parameters for the oxidation of the newly discovered substrates were comparable with those for 2,2′-azino-bis (3-ethylbenzthiazoline-6-sulfonate) (ABTS) oxidation by laccase. Electrochemical experiments demonstrated that oxidation of these compounds yielded two high-potential intermediates capable of oxidizing veratryl alcohol, which was used as a lignin model substrate, to the corresponding aldehyde and acid. 1-(3′-Sulfophenyl)-3-methylpyrazolone-5 was about 30–40% as effective in degrading veratryl alcohol compared to ABTS as judged from high-performance liquid chromatography kinetic studies. 1-Phenyl-3-methyl-pyrazolones may be of commerical interest for oxidoreductase-catalyzed biodegradation of organic compounds.     

Synthesis and crystal structure determination of iridium(III) acetylacetonate and its Br-and I-substituted analogs

γ-Halogen-substituted iridium(III) acetylacetonates of general formula Ir(acacX)₃,where acacX = CH₃ -CO-CX-CO- CH₃,X =Br, I, were synthesized. The compounds are characterized by melting points and chemical analysis data for C, H, Br, and I. An X-ray diffraction analysis was performed for iridium(III) acetylacetonate and its y-substituted analogs, crystal data were obtained, and crystal structures were determined. The crystals are monoclinic;the structures are molecular. Crystal data: Ir(acac)3 _- IrO₆C₁₅H₂₁,a = 13.900(2), b = 16.440(3), c = 7.494(2) å, γ =98.63(2)?, V= 1693.2 å³,space group P2₁/b,Z = 4, d_calc =1.92 g/cm³,sin θ/λ_max = 0.703, F_hkl = 2841, R = 0.044. Ir(acacBr)_3- IrBr₃O₆C₁₅H₁₈,a = 12.794(2), b = 15.753(2), c = 9.990(2) å Β = 105.76(2)?, V= 1937.6 å³,space group P2₁/n,Z =4, d_calc =2.49 g/cm³, sinθ/λ_max = 0.702, F_hkl = 1748, R = 0.048. Ir(acacI)3- M₃O₆C₁₅H₁₈,a = 12.855(2), b = 10.136(2), c =16.338(3)å, Β = 104.6(2)?, V=2059.8å³,space group P2₁/n, Z =4, d_calc = 2.79g/cm³, θ_max =25?, F_hkl = 2817, R =0.032. The Ir..Ir distances were estimated to be > 7.49 å for Ir(acac)3 and > 8.10 å for Ir(acacBr)3 and Ir(acacl)₃.If the estimate is limited to 10 å, the intermolecular coordination number (ICN) in the structures is 10.     

Analysis of the hyperfine structure of the EPR spectrum of the radical ions of aryl- and diaryldiazocyanides

EPR and quantum chemical methods have been used to establish the nature of the distribution of spin density in electrochemically generated radical anions of diaryldiazocyanides. For the symmetrical diphenyldiazocyanides the unshared electron is distributed over the entire molecule, whereas the introduction of a bridge between the benzene rings leads to the localization of the unshared electron only on one fragment of the molecule.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. M. V. Lomonosov Moscow State University, 119899 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 7, pp. 1552–1556, July, 1992.     

Chemical Composition and Structure–Vacancy Disordering in Ag–Au,Cu–Au,Ag–Pd,and Cu–Pd Alloys as Factors of Their Electrocatalytic Activity

The oxalic acid electrooxidation kinetics is studied at polycrystalline electrodes of vacancy-disordered Au* and Pd* obtained by anodically modifying in 0.5 M H₂SO₄ the surface of Ag–Au, Cu–Au, Ag–Pd, and Cu–Pd alloys containing no less than 50 at. % of the noble metal. It is found that a qualitative correlation exists between variations in thermodynamic and electrocatalytic activities of both Au* and Pd* following a change in the surface concentration of vacancies in alloys of constant composition and in the volume concentration of the electronegative component in alloys with approximately identical concentrations of vacancies. Such a correlation may be due to the existence of some factor through which an anodically-modified alloy affects the electrocatalytic process. The factor, presumably the alloy's electronic structure, is more generic than the alloy's volume composition, the nature of components, and the vacancy concentration.     

Crystal structure and properties of the new vanadyl(IV)phosphates Na2MVO(PO4)2, M=Ca and Sr

Two new complex vanadyl(IV)phosphates Na₂MVO(PO₄)₂ (M=Ca, Sr) were synthesized in evacuated quartz ampoules and investigated by means of X-ray diffraction, electron microscopy, DTA, ESR and magnetic susceptibility measurements. The crystal structure of Na₂SrVO(PO₄)₂ was solved ab initio from X-ray powder diffraction data. Both compounds are isostructural: a=10.5233(3) Å, b=6.5578(2) Å, c=10.0536(3) Å and a=10.6476(3) Å, b=6.6224(2) Å, c=10.2537(3) Å for Ca and Sr, respectively; S.G. Pnma, Z=4. The compounds have a three-dimensional structure consisting of V⁴⁺O₆ octahedra connected by PO₄ tetrahedra via five of the six vertexes forming a framework with cross-like channels. The strontium and sodium atoms are located in the channels in an ordered manner. Electron diffraction as well as high-resolution electron microscopy confirmed the structure solution. The new vanadylphosphates are Curie-Weiss paramagnets in a wide temperature range down to 2 K with θ=12 and 5 K for Ca and Sr phases, respectively.     

Synthesis and properties of derivatives ofsym-triazine. 15. Synthesis of amine derivatives ofsym-triazine that contain indole groups

By the cyclocondensation of imino esters of acids of the indole series with N-acylguanidines, 2-amino-4,6-disubstituted sym-triazine are obtained that contain indole groups. The reaction of N-(indolyl-3-imidolyl)-guanidine with esters of carboxylic acids leads to 2-amino-4-(3-indolyl)-6-substituted sym-triazines. Indolyl-containing N-subsitituted 2,4-diamino-sym-trizines are synthesized by the reaction of imino esters of indole acids with biguanides. Similar products are also formed when 2-amino-4-trichloromethyl-sym-triazines that contain indole substituents react with dimethylamine, morpholine, or furfurylamine.I. M. Gubkin State Petroleum and Gas Academy, Moscow, 117917. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 214–223, February, 1995. Original article submitted December 21, 1994.     

Synthesis of polyacetylene with sulfoxide functions

Polyacetylene functionalized by sulfoxide groups was synthesized from poly(methyl vinyl sulfoxide) by the elimination of methanesulfenic acid under the action of a strong base at 20—50 °C.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 774–776, March, 2005.