Temperature-programmed reaction of methane with Re- and Pt-containing oxide contacts

Mass-spectrometric data for the products of temperature-programmed reaction of methane with Re- and Pt-containing Al₂O₃ contacts show that the active sites for methane conversion to benzene over these systems are formed during high-temperature contact of these systems with methane.

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- Re, Pt- , , , .

     

O-Directed free-radical hydrostannations of propargyl ethers, acetals, and alcohols with Ph3SnH and Et3B

[reaction: see text] The O-directed hydrostannation of various propargyloxy substrates is reported with Ph(3)SnH/Et(3)B.     

Reaction of 9-amino(phenylamino)methylene- and 9-α-aminobenzylidene-4-azafluorenes with some electrophilic reagents

It was shown that initial protonation of 9-aminomethylene-4-azafluorene takes place at the pyridine nitrogen atom. In nitrosation of this azafluorene, 4-azafluorenone oxime is formed, and in reaction with dichlorocarbene, 1-amino-2, 2'-dichlorospiro[4-azafluorene-9,3-cyclopropane] is formed. Acylation yields mono- or diacyl derivatives as a function of the acylating agent and reaction conditions.Russian University of National Friendship, Moscow 117923. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 527–533, April, 1995. March 14, 1995.     

Photon polarization effects inb → sγg decay

We analyze the polarization properties of photons which are produced in the unpolarizedb-quark decay,bsg. Using the structure function formalism we carry out a general analysis of the polarization characteristics of in terms of the standard Stokes parameters. The expressions for five independent structure functions are constructed in terms of the weak magnetic transition form factors of the verticesbs andbsg. Numerical calculations of the Stokes parameters and various differential distributions forbsg are performed for the two-Higgs doublet model (2HDM). We studied the dependences of all these characteristics to the model parameters. These results were compared with the Standard Model predictions for different top quark masses. Strong sensitivity of the Stokes parameters, which defines the linear photon polarization, to the model is demonstrated.     

Synthesis and certain transformations of γ-nitrosoalcohols

The -nitrosoalcohols (II), (XII), and (IX), respectively, have been synthesized by acid-catalyzed hydrolysis of 2-alkoxyisoxazolidines (I), (Xa, b), (Xla, b), and 3-(dimethoxyamino)-3-trifluoromethylbutanol-1 (VIII). The nitrosoalcohol (II) readily rearranges into the oxime (III), and (XII) is converted into the diol (XIII) by oxidation with atmospheric O₂ and denitrosation. For (IX) and (XII) ring-chain tautomerism with formation of 2-hydroxyisoxazolidines could not be detected by PMR spectroscopy.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1563–1568, July, 1991.