On the extremality of the disordered state for the Ising model on the Bethe lattice

We give a simple proof that the limit Ising Gibbs measure with free boundary conditions on the Bethe lattice with the forward branching ratio k2 is extremal if and only if is less or equal to the spin glass transition value, given by tanh( _c ^SG = 1/k.The work was partially supported by the NSF grant DMS 9504513.     

A high-power X-band pulsed microwave induced catalytic decomposition of methane with integral acoustic measurements

A high-power microsecond pulsed microwave system operating in the X-band region was used for the catalytic conversion of methane. Microwave microsecond pulses at repetition rates of 50 and 80 Hz were used to initiate chemical reactions. The Microwave-Induced Acoustic technique was employed in combination with gas chromatography for on-line detection of chemical products. Methane was converted to C₂ and C₃ hydrocarbons. The selectivity of ethane in hydrocarbon products can be >90 %. The contribution of hydrogen evolution and carbon deposition has been shown to be important. A comparison between previous experiments performed with millisecond pulse durations is given.     

Reactions of 1-aryl-2-bromodiazene 1-oxides with acids and bases

The reactions of 1-aryl-2-bromodiazene 1-oxides with HCl in nonaqueous media give aryldiazonium chlorides, while 1,3,3-substituted triazenes-1 are formed in the reactions with secondary amines. Using 2-{¹⁵N} label, it was shown that the aryl group does not migrate in these reactions. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 613–615, March, 1997.     

Chemistry of <Emphasis Type="Italic">N,N</Emphasis>-bis(silyloxy)enamines 7. Quaternization of tertiary amines and nitrogen-containing heterocycles by <Emphasis Type="Italic">N,N</Emphasis>-bis(silyloxy)enamines

Coupling of N,N-bis(silyloxy)enamines with tertiary amines and nitrogen-containing heterocycles affording the corresponding functionalized ammonium or iminium salts was studied. The area of its application was determined, and optimal procedures for the synthesis of the target products were proposed. The mechanism including the formation of conjugated nitroso alkene or a silylnitrosonium cation as key intermediates is discussed.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2137–2143, October, 2004.     

Photoelectron spectroscopy of isolated multiply negatively charged oligonucleotides

Ultraviolet photoelectron spectroscopy in an ion beam was used to investigate the electronic properties of isolated DNA oligonucleotides [dA(5)-4H](4-) and [dT(5)-4H](4-), carrying four excess negative charges. We find the fourth adiabatic electron affinity to be slightly negative for [dA(5)-4H](4-), while it is positive for [dT(5)-4H](4-). This implies a significant influence of the base composition on energetics, which is in turn relevant for analytic applications and also for charge transport properties.     

Synthesis of brominated 2-(tert-butyl-NNO-azoxy)anilmes

2-(tert-Butyl-NNO-azoxy)aniline was prepared by selective reduction of 2-(tert-butyl-NNO-azoxy)nitrobenzene. Its bromination yielded the correspondingpara-bromo- andortho, para-dibromoanilines (3a,b).meta-Bromoanilines (6a,b) were synthesized by selective replacement of theortho-bromine atoms in ortho,para-bromo(tert-butylazoxy)benzenes (5a,b) by ammonia in toluene under pressure.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1620–1623, September, 1994.This work was carried out with the financial support of the Russian Foundation for Basic Research (Project No. 93-03-18461).     

Unusual transfoemation of trimethylsilyl ester of 5-chloromethyl-2-isoxazoline-3-carboxylic acid

Conclusions The silylation of 5-chloromethyl-2-isoxazoline-3-carboxylic acid with the usual silylating agents leads to the corresponding trimethylsilyl ester, which when heated is converted to 4-chloro-3-trimethylsiloxybutyronitrile.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2818–2819, December, 1981.