Analysis of the interaction kinetics of two phases in a binary system. Formulation of the problem,model, and method

An approach to the analysis of the interaction kinetics of two phases in a binary system is outlined, on the basis that: 1) the rates of transfer of the matter of the components through the phase boundary, the rates of boundary motion, and the diffusional flux densities in the boundary layers are represented as explicit functions of the boundary concentrations of foreign components in the phases c ^B and c ^A ; 2) the features of the system behavior in various regions of the field of values of c ^B and c ^A are considered; 3) the trajectory of the process in the space of the parameters c ^B and c ^A is determined.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 43–49, June, 1985.     

Laser-induced reactions of NO2 in the visible region

The reaction of NO₂ with isobutane, induced by 488 nm laser radiation, to form 2-nitro-2-methylpropane has been investigated and the results computer-modeled according to two possible reaction mechanisms. The first scheme involves the direct abstraction of H from isobutane by vibronically excited NO₂ (NO ₂ ^* ), and the second, abstraction by an intermediate NO₃ radial produced by NO ₂ ^* +NO₂. The modeling results strongly support the NO ₂ ^* scheme as the dominant reaction mechanism.     

Synthesis of o- and m-Carborane-substituted Porphyrins of the Natural Type

Basing on protoporphyrin IX, its monobenzyl ester, deuteroporphyrin IX, 9-hydroxymethyl-m- and 9-hydroxymethyl-p-carboranes, mono- and dicarborane-containing porphyrins were prepared.     

Conversions of 9-chloro-4-azafluorene to azalenes

The iodomethylate of 9-chloro-4-azafluorene is converted to 1H-1-methyl-indeno[1,2-b]pyridine when treated with base. We discuss the structure of compounds containing azalene fragments, which are formed upon heating 9-chloro-4-azafluorene. We discuss some considerations concerning the nomenclature of azulenes with the azafluorene skeleton.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 915–920, July 1992.     

Chemistry of 1,1,2,2-tetracyanoethane. 11. Synthesis and stereochemical characteristics of 3-methyl-5-oxo-2′-amino-5′-phenyl -3′,4′,4′-tricyanoisoxazoline-4-spiro-1′-cyclopent-2′-ene

The Michael condensation of 1,1,2,2-tetracyanoethane with 3-methyl-4-benzylideneisoxazolin-5-one having the Z configuration leads to a heterocyclic spiran with retention of the cis orientation of the phenyl and keto groups. The deviations of the series of bond angles of the spiran from the standard values, the abnormal lengths of the C-C bonds adjacent to the gem-dicyano group, and the appearance of nonbonding >C=O(...)CN interactions and conjugation effects in the enaminonitrile fragment are discussed.For Communication 10, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1404–1410, October, 1988.     

Comparative study of reflectance cells for PLS-FTIR determination of sugars in soft drinks

A comparative study has been carried out between a horizontal Attenuated Total Reflectance (h-ATR) cell and a Cylindrical Internal Reflection (CIR) cell (CIRCLE cell). Both cells were employed for the determination of glucose, fructose, sucrose and total sugar in soft drinks and fruit juices using absorbance measurements at two resolution values (4 and 8 cm^–1). Data were processed by Partial Least Squares regression (PLS). Using a resolution of 4 cm^–1, mean relative errors of prediction from 0.6% to 1.3% were obtained using the horizontal-ATR and from 0.6% to 2.8% using the CIRCLE cell resulting in a limit of detection from 0.03% in the case of sucrose to 0.21% for total sugar for the h-ATR and from 0.06% for sucrose to 0.13% for glucose using the CIRCLE cell. Both cells provided appropriate figures of merit, but the analytical sensitivity obtained using the h-ATR cell was three times higher than that obtained using the CIRCLE cell.