Some derivatives of 3-aryl-2H-1,4-benzoxazine

Arylacyl esters of o-acetamidophenol, which are cyclized to 3-aryl-2H-1,4-benzoxazines by a saponification of the acetamido group, are obtained by the reaction of -bromomethyl aryl ketones with potassium o-acetamidophenoxide.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 164–166, February, 1971.     

Synthesis of some 1-substituted 2,5-diphenylimidazoles

The synthesis of 1,2,5-triphenylimidazole derivatives was accomplished by reaction of -benzamidoacetophenone with primary aromatic amines in the presence of phosphorus trichloride.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1264–1265, September, 1972.     

Reaction of 3-aryl-2-benzoyloxiranes with alkyl thiocyanates

3-Aryl-2-benzoyloxiranes and alkyl thiocyanates in the presence of an equivalent amount of anhydrous AlCl₃ form erythro-N-(2-benzoyl-l-aryl-2-chloroethyl)-S-alkyl thiocarbamates and -diketones. p-Toly1- and p-anisy1-2-benzoy1-oxiranes do not react with alkyl thiocyanates, but isomerize to the respective -diketones, and form the threo-chlorohydrins in low yield.Translated from Khimiya Geterotsilklicheskikh soedinenii, No. 12, pp. 1624–1628, December, 1985.     

Spallation neutron production and the current intra-nuclear cascade and transport codes

A recent renascent interest in energetic proton-induced production of neutrons originates largely from the inception of projects for target stations of intense spallation neutron sources, like the planned European Spallation Source (ESS), accelerator-driven nuclear reactors, nuclear waste transmutation, and also from the application for radioactive beams. In the framework of such a neutron production, of major importance is the search for ways for the most efficient conversion of the primary beam energy into neutron production. Although the issue has been quite successfully addressed experimentally by varying the incident proton energy for various target materials and by covering a huge collection of different target geometries --providing an exhaustive matrix of benchmark data-- the ultimate challenge is to increase the predictive power of transport codes currently on the market. To scrutinize these codes, calculations of reaction cross-sections, hadronic interaction lengths, average neutron multiplicities, neutron multiplicity and energy distributions, and the development of hadronic showers are confronted with recent experimental data of the NESSI collaboration. Program packages like HERMES, LCS or MCNPX master the prevision of reaction cross-sections, hadronic interaction lengths, averaged neutron multiplicities and neutron multiplicity distributions in thick and thin targets for a wide spectrum of incident proton energies, geometrical shapes and materials of the target generally within less than 10% deviation, while production cross-section measurements for light charged particles on thin targets point out that appreciable distinctions exist within these models. Received: 22 May 2001 / Accepted: 3 September 2001     

Implantation of helium and deuterium ions into tungsten-coated composite structures

Various processes occurring in tungsten coatings deposited on composite substrates under ion irradiation have been analyzed. Processes leading to formation of radiation defects of a crystal lattice, helium and deuterium accumulation, and their thermodesorption from samples are compared. Possible mechanisms behind these processes are discussed.     

Measurement of the positive muon lifetime and determination of the Fermi constant to part-per-million precision

We report a measurement of the positive muon lifetime to a precision of 1.0 ppm; it is the most precise particle lifetime ever measured. The experiment used a time-structured, low-energy muon beam and a segmented plastic scintillator array to record more than 2×10(12) decays. Two different stopping target configurations were employed in independent data-taking periods. The combined results give τ(μ(+)) (MuLan)=2?196?980.3(2.2) ps, more than 15 times as precise as any previous experiment. The muon lifetime gives the most precise value for the Fermi constant: G(F) (MuLan)=1.166?378?8(7)×10(-5) GeV(-2) (0.6 ppm). It is also used to extract the μ(-)p singlet capture rate, which determines the proton's weak induced pseudoscalar coupling g(P).     

Mass spectra and 13C NMR spectra of the adducts of epoxyenamines with sulfene

The behavior of the adducts of alicyclic epoxyenamines with sulfene under electron impact and also their ¹³C NMR spectra were studied. The initial fragmentation of these compounds, which takes place with the ejection of sulfene, is accompanied by a specific hydrogen rearrangement of the molecular ion. The degree of substitution of the cyclohexane ring has a significant effect on the nature of the subsequent dissociation, which leads to extensive degradation of the oxirane ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 267–271, February, 1986.     

Molecular polarizability of organic compounds and their complexes: XLIX. Molar volumes of polyaryl systems in solutions, extrapolated to infinite dilution, their additivity, and steric structure of the molecules

Molar volumes of a number of polyaryls and of several model systems at infinite dilution in carbon tetrachloride and benzene were determined. The molar volumes of the compounds under study are additive by bonds, groups, and molecular fragments. The dipole moments and Kerr molar constants of the compounds under study can be found by a simplified additive method. As follows from the additive analysis of the molar volumes of diphenyl, para-substituted diphenyls, heteroaromatic analogs, and a number of polyaryls, the molecules of these compounds are acoplanar in the solutions, and the degree of their acoplanarity is the same as in diphenyl.