4-hetarylidene-2-aryloxazol-5-ones

The corresponding 4-hetarylidene-2-aryloxazol-5-ones were synthesized by condensation of furyl- and thienyl-containing aldehydes with hippuric acid and substituted hippuric acids via the Erlenmeyer-Plöchl reaction. The electronic absorption and fluorescence spectra of the compounds in toluene were investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1624–1627, December, 1979.Original article submitted April 17, 1979.     

Nitration of 2-(2-quinolyl)thiophene and 5-(2-quinolyl)-2,2′-dithiophene

2-(2-Quinolyl)thiophene is nitrated in the 5 position, while its 2-thiophenyl analog is nitrated in the 3′ and 5′ positions simultaneously.     

Study of some nitrogen compounds of 2,2′-dithienyl

5-Formyl-5-nitro-2,2-dithienyl and 5-formyl-3-nitro-2,2t'-dithienyl were obtained by nitration of 5-formyl-2,2t'-dithienyl with copper nitrate in acetic anhydride. The structures of the nitroaldehydes were established by their oxidation to the corresponding nitro acids of the 2,2-dithienyl series, the decarboxylation of which yielded 5-nitro- and 3-nitr o-2,2 -dithienyls.See [1] for communication II.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 918–919, July, 1971.     

Composite coatings based on copper oxides electrodeposited from solutions and on polymers

The possibility of obtaining composite coatings consisting of metal oxides deposited from solutions with an asymmetric ac current and of a polymer was studied. Protective properties of the composite coatings were examined.     

A Dynamic Nuclear Polarization spectrometer at 95 GHz/144 MHz with EPR and NMR excitation and detection capabilities

A spectrometer specifically designed for systematic studies of the spin dynamics underlying Dynamic Nuclear Polarization (DNP) in solids at low temperatures is described. The spectrometer functions as a fully operational NMR spectrometer (144 MHz) and pulse EPR spectrometer (95 GHz) with a microwave (MW) power of up to 300 mW at the sample position, generating a MW B(1) field as high as 800 KHz. The combined NMR/EPR probe comprises of an open-structure horn-reflector configuration that functions as a low Q EPR cavity and an RF coil that can accommodate a 30-50 μl sample tube. The performance of the spectrometer is demonstrated through some basic pulsed EPR experiments, such as echo-detected EPR, saturation recovery and nutation measurements, that enable quantification of the actual intensity of MW irradiation at the position of the sample. In addition, DNP enhanced NMR signals of samples containing TEMPO and trityl are followed as a function of the MW frequency. Buildup curves of the nuclear polarization are recorded as a function of the microwave irradiation time period at different temperatures and for different MW powers.     

The quark model and b baryons

The recent observation at the Tevatron of (uub and ddb) baryons within 2 MeV of the predicted Σ_b-Λ_b splitting and of baryons at the Tevatron within a few mega electron volts (MeV) of predictions has provided strong confirmation for a theoretical approach based on modeling the color hyperfine interaction. The prediction of  = 5790-5800 MeV is reviewed and similar methods used to predict the masses of the excited states and . The main source of uncertainty is the method used to estimate the mass difference m_b-m_c from known hadrons. We verify that corrections due to the details of the interquark potential and to Ξ_b- mixing are small. For S-wave qqb states we predict , and . For states with one unit of orbital angular momentum between the b quark and the two light quarks we predict , and . Results are compared with those of other recent approaches.