N-Arylation of azoles with low basicity by 1,4-dimethoxybenzene during undivided electrolysis

The reactions of 1,4-dimethoxybenzene with 4-nitropyrazole, 3,4-dinitro-5-methylpyrazole, 1,2,4-triazole, 3-nitro-1,2,4-triazole, and tetrazole were studied during undivided amperostatic electrolysis on a Pt electrode in MeCN, CH₂Cl₂, and MeOH. The main reaction products were 2-azolyl-1,4-dimethoxybenzenes and (or) 1,4-diazolyl-1,4-dimethoxycyclohexa-2,5-dienes. In all cases except 1,2,4-triazole, N-arylation occurs only in the presence of the Alk₄N⁺ salts of azoles or 2,4,6-trimethylpyridine as a base. The mechanism of the reactions is discussed.     

Applying scattered-ion spectroscopy to the analyzing of plasma-surface interactions

A setup based on an ion mass monochromator and intended for investigating plasma interactions with surfaces of plasma facility materials is described. It analyzes the composition and thickness of surface films by means of ion scattering spectroscopy. An analysis of the composition of stainless steel and graphite is performed using helium and argon ions in the range of 2?C8 keV. The obtained results demonstrate the possibility of investigating the dynamics of carbon and oxygen behavior on the surface of materials using negatively charged recoil ions and scattered helium ions.     

Discharge Characteristics of the Penning Plasma Source

The results of investigation of discharge characteristics of the Penning plasma source are presented. Volt-ampere characteristics (VAC), energy distribution, and mass-charge composition of ions emitted from the discharge under different modes of its combustion were measured. The connection between the discharge current bursts and increase in the potential drop (up to 50% of the anode voltage) is established. The measured VACs agree well with the theoretical dependencies. It is shown that the content of atomic hydrogen ions increases from 5 to 10% with an increase in the anode voltage from 1 to 3.5 kV and the power applied in the discharge (from 0.2 to 3 W).     

Modeling of the mechanism for the acidolysis of epichlorohydrin by aliphatic and aromatic carboxylic acids catalyzed by amines

A model was constructed for the mechanism of the reaction of aliphatic and aromatic carboxylic acids with epichlorohydrin catalyzed by tertiary amines. A mechanism for the catalysis of the transfer of the anion of the nucleophilic reagent by an ion pair was proposed taking account of the kinetic data and selected chemical and mathematical models.     

On q-Analogues of Bounded Symmetric Domains and Dolbeault Complexes

A very well known result by Harish-Chandra claims that any Hermitiansymmetric space of non-compact type admits a canonical embedding into acomplex vector space V. The image of this embedding is a bounded symmetricdomain in V. This work provides a construction of q-analogues of apolynomial algebra on V and the differential algebra of exterior forms on V.A way of producing a q-analogue of the bounded function algebra in a boundedsymmetric domain is described. All the constructions are illustrated bydetailed calculations in the case of the simplest Hermitian symmetric spaceSU (1,1)/U(1).     

Electronic absorption spectra determination of C60 content in soot produced in hydrocarbon flames

We analyze the possibilities of eliminating hydrocarbon compounds from soot produced in hydrocarbon flames for the purpose of using the method of electronic absorption spectra to measure the content of fullerenes. The sensitivity limit of the spectral-absorption method has been determined. The solubility of C₆₀ in ether has been measured. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 4, pp. 253–256, March–April, 2000.     

Photophysics of boron difluoride chelates with dihalogenated tetraphenyl-<Emphasis Type="Italic">ms</Emphasis>-azadipyrromethenes

Spectral, luminescent, and photophysical properties of the BF₂ chelates with dichloroand dibromotetraphenyl-ms-azadipyrromethene (derivatives of tetraphenyl-aza-BODIPY) have been studied experimentally and theoretically by quantum chemistry methods. The positions of fluorescence bands, quantum yields, and lifetimes were measured experimentally. The rate constants of intramolecular photophysical processes have been estimated, and the quantum yields of fluorescence and phosphorescence and the lifetimes of excited states have been calculated. Complete energy schemes of electronically excited states and photophysical processes in the molecules of the compounds under study have been built on the basis of calculation results. The decrease in the fluorescence quantum yields upon excitation into the second absorption band and the absence of the phosphorescence of the chelates have been explained.     

Investigation of the peculiarities of Ge island growth on Si (100) under MBE conditions

The results of investigating the features of Ge-island formation on Si (100) under conditions of molecular-beam epitaxy is presented. Nanosized structures at heteroboundaries (islets and quantum dots) are attracting great interest due to new useful properties and broad prospects of their application.