Thermodynamic properties of cytisine dithiocarbamate derivatives

The heat of solution in water and the heat capacity in the range 173 K-T _m of triethylammonium, sodium, and potassium dithiocarbamates derived from cytisine were studied by calorimetry. The heats of combustion and melting and the standard enthalpies of formation of the compounds were calculated.     

Throwing power of a dilute sulfuric acid copper plating electrolyte during intensive electrodeposition

A method of determination of the throwing power (TP) of electrolytes in conditions of forced convection in a Hull cell with a rotating cylindrical electrode is presented. The method is used to determine TP of a copper plating electrolyte containing 0.15–0.5 M CuSO₄ and 1 M H₂SO₄ at current densities of up to 75 mA cm^-2. The TP decreases with increasing current density at a constant i _av/i _d ratio, where i _av is the average working current density and i _d the limiting diffusion current density. With increasing the i _av/i _d ratio due to an increase in the cathodic polarizability conditions for an increase in TP may be achieved. In optimum (for uniform deposition) modes, i _av/i _d 0.4–0.5. The TP may increase upon diluting electrolyte with respect to its main component.Translated from Elektrokhimiya, Vol. 41, No. 1, 2005, pp. 91–96.Original Russian Text Copyright © 2005 by Dikusar, Bobanova, Yushchenko, Yakovets.To the Centennial of B.N. Kabanov.     

Fluorescent properties of cationic-anionic polymethine dyes

The fluorescence spectra were studied and the quantum yields of the fluorescence of a number of cationic-anionic polymethine dyes were measured in polar, low-polarity, and nonpolar solvents. It was shown that the fluorescence spectra of cationic-anionic dyes in polar solvents, like the absorption spectra, represent the sum of the fluorescence spectra of the corresponding cationic and anionic dyes. For dyes in which the absorption bands of the anion and cation are close and a new short-wave band arises in the ion pairs, excitation into this band virtually does not lead to fluorescence, which is a consequence of the forbidden nature of the long-wave transition that arises as a result of the interaction of the chromophores. For a number of cationic-anionic dyes in ion pairs an energy transfer is observed: When an ion possessing short-wave absorption is excited, an ion with long-wave absorption fluoresces.N. N. Semenov Institute of Chemical Physics, Russian Academy of Sciences, 117977 Moscow. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2532–2539, November, 1992.     

Reaction of dimethylaminomethylenemalonaldehyde bis-N,O-acetal with ketones. A novel route to N-methylpyrroles

Condensation of the bis-N,O-acetal of amethylarrtinomethylenerrzalonaldehyde with ketones, -dimethylaminovinylketones, and -dimethylaminodienones is accompanied by an unusual intramolecular cyclization to give cross conjugated cyclic or acylic ketones containing an N-methyl pyrrole ring in the - or - and'-positions. This is a novel route to substituted pyrroles. Treatment of the bis-N,O-acetal of dimethylaminomethylenemalonaldehyde with 2-(3'-dimethylaminopropen-2'-ylidene)cyclopentanone gave a polyenyl tris-dimethylaminodiketone.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, Moscow 117913. Translated from Khimiya Geterotsiklicheskikh Soednenii, No.5, pp. 654–662, May, 1996. Original article submitted February 14, 1996.     

Study on the United Glucose Oxidase Electrode Constructed by Composite Electrode

A novel type of united glucose oxidase (GOD) electrode was designed. Glucose oxidase and ferrocene (Fc), which was a mediator, were added into the composite electrode that was constructed by graphite powder, acetylene black, and epoxy resin. These three materials in composite electrode kept constant proportion in weight. And the optimum amounts of GOD and Fc among united enzyme electrode were 5% and 2%, respectively. The glucose was detected linearly in the concentration range 0.01–9.0 mM with a 20-s steady-state response time and 36 nA/mM of the sensitivity at 0.15 V applied potential. And electrode fouling problem and the response current from the interferents were avoided. The response current of the united GOD electrode had no obvious deterioration within 80 days when stored at 4°C in a refrigerator. The detecting results of human serum by the united GOD electrode had good consistency with that by standard enzyme method. The maximum deviation between these two detecting values was 5%. It might be used for detecting the blood sugar in clinical assay.     

Transformations of polymers and copolymers of acrylonitrile during heterogeneous saponification

The kinetic and thermodynamic specific features of the process of heterogeneous alkaline saponification of the copolymer of acrylonitrile (92.2%), methyl acrylate (6.3%), and sodium monoithaconate (1.5%) were investigated. Chemical and infrared spectroscopic methods reveal that the saponification of the nitrile groups of copolymer of acrylonitrile proceeds faster to yield amide groups and then slower to yield carboxylate groups. The order of both stages of the process with respect to the accumulation of the respective groups was evaluated. The dependence of the rate of saponification on the packing density of the structural units was demonstrated. With increasing conversion, the fiber structure becomes looser, as demonstrated by density and sorption investigations. If acrylonitrile copolymer is treated with alkali, the carboxylate groups in the polymer substrate accumulate as a result of saponification of the ester groups of the copolymer, while the nitrile groups are predominantly transformed into the amide groups. If the degree of conversion (with respect to the CN groups) is higher than 62.7%, the copolymer abruptly suffers a marked change in its mechanical properties and gradually dissolves. The products of partial saponification of copolymer were investigated by thermomechanical methods and DTA. The polycyclization of the polymer substrate was found to proceed at a temperatures which decreases as the content of the amide groups increases.     

Stereochemical dependence of chemical shifts of13C carbonyl carbon atoms in conjugated ω-amino-, alkoxy-, alkyl-, dialkyl-, phenyl-α-carbonyl-, and α,α′-dicarbonyl-containing compounds

Stereospecificity has been shown for the¹³C chemical shift (CS) of carbonyl carbon atoms for monoene, diene, and triene ketoesters; monoene, diene, and triene linear diketones; diene and triene cyclohexadiketones; linear diene and triene diesters, pyrazolones and imides: CO (trans) > CO (cis). The influence of structural factors on the¹³C CS is examined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 6, pp. 1304–1314, June, 1990.     

Sulfenyl Halides in the Synthesis of Heterocycles. 2. Cyclization in Reactions of Hetarenesulfenyl Chlorides with 3,3-Dimethyl-1-butene

Products of additive cyclization with ring closure at the nitrogen atom of the thiohetaryl unit were synthesized by the interaction of 4,6-dimethylpyrimidine-2-, 3-cyano-4,6-dimethylpyridine-2-, quinoline-8-, and 1,3-benzothiazole-2-sulfenyl chlorides with 3,3-dimethyl-1-butene. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, 893–900, June, 2005.     

Terpenoids of the oleoresins ofPicea orientalis andAbies normanniana growing in the Caucasus

The terpenoid compositions of the oleoresins of the oriental spruce and of the Nordmann fir growing in the Caucasus have been studied. From the oleoresin ofPicea orientalis (L.) Link, which belongs to the sectionOmorica, 32 mono-, sesqui-, and diterpene compounds have been identified, and fromAbies nordmanniana Stev. 37 mono-, sesqui, and diterpene compounds. Together with other diterpenoids that are characteristic for the oleoresins of all species of fir, methyl dehydroabietate and methyl 15-hydroxy dehydroabietate have been found in the oleoresin of the Nordmann fir. Three new sesquiterpene hydrocarbons have been isolated.